How to objectively measure snoring: a systematic review

PURPOSE

Snoring is the most common symptom of obstructive sleep apnea. Various objective methods of measuring snoring are available, and even if the measurement is performed the same way, communication is difficult because there are no common reference values between the researcher and clinician with regard to intensity and frequency, among other variables. In other words, no consensus regarding objective measurement has been reached. This study aimed to review the literature related to the objective measurement of snoring, such as measurement devices, definitions, and device locations.

METHODS

A literature search based on the PubMed, Cochrane, and Embase databases was conducted from the date of inception to April 5, 2023. Twenty-nine articles were included in this study. Articles that mentioned only the equipment used for measurement and did not include individual details were excluded from the study.

RESULTS

Three representative methods for measuring snoring emerged. These include (1) a microphone, which measures snoring sound; (2) piezoelectric sensor, which measures snoring vibration; and (3) nasal transducer, which measures airflow. In addition, recent attempts have been made to measure snoring using smartphones and applications.

CONCLUSION

Numerous studies have investigated both obstructive sleep apnea and snoring. However, the objective methods of measuring snoring and snoring-related concepts vary across studies. Consensus in the academic and clinical communities on how to measure and define snoring is required.

Validation of Korean Olfactory Questionnaire for Perioperative Olfactory Assessment in Endoscopic Endonasal Skull Base Surgery

Objective: To analyze changes in olfactory function after endoscopic endonasal skull base surgery and compare performance of the olfactory questionnaire with those of conventional psychophysical tests. Methods: Patients were classified into 5 categories for olfactory function evaluation (normal, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia) based on a self-assessment. Patients also underwent the butanol threshold test (BTT), Cross-Cultural Smell Identification Test (CCSIT), and 11-item olfactory questionnaire. Subjects with normosmia preoperatively and who were followed up at least 6 months after surgery were analyzed. Receiver operating characteristic curves and confusion matrix analysis were performed for BTT, CCSIT, and olfactory questionnaire to compare their diagnostic abilities. The effects of age, preoperative olfaction, septal flap, tumor pathology, and tumor size on postoperative olfaction were evaluated using multivariate linear regression analysis. Results: Data from 108 patients were analyzed. Postoperative changes in the olfactory questionnaire were significantly associated with changes in the BTT and CCSIT. The area under the curve for postoperative self-olfactory function classification was highest for olfactory questionnaire (0.894), followed by BTT (0.767) and CCSIT (0.688). Patient age at the time of surgery and preoperative BTT score were significantly related to postoperative olfactory outcomes. Conclusion: The olfactory questionnaire correlated well with conventional psychosomatic olfactory function tests. In combination with clinical parameters and preoperative psychosomatic olfactory function tests, the olfactory questionnaire is suitable for assessing subjective olfactory function after endoscopic endonasal skull base surgery.

Treatment Outcome of Olfactory Neuroblastoma: A Multicenter Study by the Korean Sinonasal Tumor and Skull Base Surgery Study Group

Objectives

Due to the rarity of olfactory neuroblastoma (ONB), there is an ongoing debate about optimal treatment strategies, especially for early staged or locally advanced cases. Therefore, our study aims to explore experiences from multiple centers, focusing on factors that influence the oncological outcomes of ONB.

Methods

We retrospectively analyzed 195 ONB patients treated at nine tertiary hospitals in South Korea between December 1992 and December 2019. Kaplan-Meier survival analysis was used to evaluate oncological outcomes, and the Cox proportional hazards regression model was employed to analyze prognostic factors for survival outcomes. Furthermore, we conducted 1:1 nearest-neighbor matching to investigate differences in clinical outcomes according to the use of neoadjuvant chemotherapy.

Results

In our cohort, the 5-year overall survival rate (OS) was 78.6%, and the 5-year disease-free survival rate (DFS) was 62.4%. The Cox proportional hazards model revealed that the mKadish stage and Dulguerov T status were significant for DFS, while the mKadish stage and Hyams grade were identified as prognostic factors for OS. The subgroup analyses indicated a trend toward improved 5-year DFS with dural resection in mKadish A and B cases, even though that result was statistically insignificant. Induction chemotherapy did not provide a survival benefit in this study after matching for the mKadish stage and nodal status.

Conclusion

Clinical staging and pathologic grading are important prognostic factors in ONB. Dural resection in mKadish A and B did not show a significant survival benefit. Induction chemotherapy did not show a survival benefit, even after stage matching.

PA2G4/EBP1 ubiquitination by PRKN/PARKIN promotes mitophagy protecting neuron death in cerebral ischemia

Cerebral ischemia induces massive mitochondrial damage, leading to neuronal death. The elimination of damaged mitochondria via mitophagy is critical for neuroprotection. Here we show that the level of PA2G4/EBP1 (proliferation-associated 2G4) was notably increased early during transient middle cerebral artery occlusion and prevented neuronal death by eliciting cerebral ischemia-reperfusion (IR)-induced mitophagy. Neuron-specific knockout of Pa2g4 increased infarct volume and aggravated neuron loss with impaired mitophagy and was rescued by introduction of adeno-associated virus serotype 2 expressing PA2G4/EBP1. We determined that PA2G4/EBP1 is ubiquitinated on lysine 376 by PRKN/PARKIN on the damaged mitochondria and interacts with receptor protein SQSTM1/p62 for mitophagy induction. Thus, our study suggests that PA2G4/EBP1 ubiquitination following cerebral IR-injury promotes mitophagy induction, which may be implicated in neuroprotection.Abbreviations: AAV: adeno-associated virus; ACTB: actin beta; BNIP3L/NIX: BCL2 interacting protein 3 like; CA1: Cornu Ammonis 1; CASP3: caspase 3; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; DMSO: dimethyl sulfoxide; PA2G4/EBP1: proliferation-associated 2G4; FUNDC1: FUN14 domain containing 1; IB: immunoblotting; ICC: immunocytochemistry; IHC: immunohistochemistry; IP: immunoprecipitation; MCAO: middle cerebral artery occlusion; MEF: mouse embryonic fibroblast; OGD: oxygen-glucose deprivation; PRKN/PARKIN: parkin RBR E3 ubiquitin protein ligase; PINK1: PTEN induced kinase 1; RBFOX3/NeuN: RNA binding fox-1 homolog 3; SQSTM1/p62: sequestosome 1; TIMM23: translocase of inner mitochondrial membrane 23; TOMM20: translocase of outer mitochondrial membrane 20; TUBB: tubulin beta class I; WT: wild-type.

In-Home Smartphone-Based Prediction of Obstructive Sleep Apnea in Conjunction With Level 2 Home Polysomnography

Importance

Consumer-level sleep analysis technologies have the potential to revolutionize the screening for obstructive sleep apnea (OSA). However, assessment of OSA prediction models based on in-home recording data is usually performed concurrently with level 1 in-laboratory polysomnography (PSG). Establishing the predictability of OSA using sound data recorded from smartphones based on level 2 PSG at home is important.

Objective

To validate the performance of a prediction model for OSA using breathing sound recorded from smartphones in conjunction with level 2 PSG at home.

Design, Setting, and Participants

This diagnostic study followed a prospective design, involving participants who underwent unattended level 2 home PSG. Breathing sounds were recorded during sleep using 2 smartphones, one with an iOS operating system and the other with an Android operating system, simultaneously with home PSG in participants' own home environment. Participants were 19 years and older, slept alone, and had either been diagnosed with OSA or had no previous diagnosis. The study was performed between February 2022 and February 2023.

Main Outcomes and Measures

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the predictive model based on the recorded breathing sounds.

Results

Of the 101 participants included during the study duration, the mean (SD) age was 48.3 (14.9) years, and 51 (50.5%) were female. For the iOS smartphone, the sensitivity values at apnea-hypopnea index (AHI) levels of 5, 15, and 30 per hour were 92.6%, 90.9%, and 93.3%, respectively, with specificities of 84.3%, 94.4%, and 94.4%, respectively. Similarly, for the Android smartphone, the sensitivity values at AHI levels of 5, 15, and 30 per hour were 92.2%, 90.0%, and 92.9%, respectively, with specificities of 84.0%, 94.4%, and 94.3%, respectively. The accuracy for the iOS smartphone was 88.6%, 93.3%, and 94.3%, respectively, and for the Android smartphone was 88.1%, 93.1%, and 94.1% at AHI levels of 5, 15, and 30 per hour, respectively.

Conclusions and Relevance

This diagnostic study demonstrated the feasibility of predicting OSA with a reasonable level of accuracy using breathing sounds obtained by smartphones during sleep at home.

Differences in Clinical and Immunological Characteristics According to the Various Criteria for Tissue Eosinophilia in Chronic Rhinosinusitis With Nasal Polyps

OBJECTIVES

Several criteria exist for classifying chronic rhinosinusitis with nasal polyps (CRSwNP) as eosinophilic or non-eosinophilic. This study attempted to evaluate several criteria for defining eosinophilic CRSwNP from clinical and immunological perspectives.

METHODS

A cohort of 84 patients (73 patients with CRSwNP and 11 control patients) was retrospectively analyzed. Patients were divided into eosinophilic and non-eosinophilic CRSwNP based on four different criteria: eosinophils (EOS) accounting for more than 20% of the total inflammatory cells; ≥70 EOS per high-power field (HPF); >55 EOS/HPF; and ≥10 EOS/HPF. Preoperative clinical characteristics, the immunological profiles of 14 cytokines from nasal tissue, and postoperative outcomes were compared between eosinophilic and non-eosinophilic CRSwNP based on each criterion. These criteria were immunologically validated by using 14 cytokines to predict the performance of tissue eosinophilia with a random forest model.

RESULTS

Patients with eosinophilic CRSwNP were significantly older when the criterion of ≥10 EOS/HPF or EOS >20% was used. The number of patients with aspirin intolerance was significantly higher in eosinophilic CRSwNP based on the criterion of EOS >20%. From an immunological perspective, non-type 2 inflammatory cytokines were significantly higher in non-eosinophilic CRSwNP with the criterion of EOS >20% of the total inflammatory cells. In addition, the criterion of EOS >20% of the total inflammatory cells resulted in the best prediction of eosinophilic CRSwNP, with an accuracy of 88.10% and area under the curve of 0.94.

CONCLUSION

Clinical and immunological characteristics were different between eosinophilic and non-eosinophilic CRSwNP depending on a variety of criteria, and the.

RESULTS

of this study should be taken into account when choosing the criterion for defining eosinophilic CRSwNP and interpreting the data accordingly.

Inflammatory Endotypes of Chronic Rhinosinusitis in the Korean Population: Distinct Expression of Type 3 Inflammation

PURPOSE

Cluster analyses on inflammatory markers of chronic rhinosinusitis (CRS) in Asians from multicenter data are lacking. This multicenter study aimed to identify the endotypes of CRS in Koreans and to evaluate the relationship between the endotypes and clinical parameters.

METHODS

Nasal tissues were obtained from patients with CRS and controls who underwent surgery. The endotypes of CRS were investigated by measuring interleukin (IL)-5, interferon (IFN)-γ, IL-17A, IL-22, IL-1β, IL-6, IL-8, matrix metalloproteinase-9, eotaxin-3, eosinophil cationic protein, myeloperoxidase (MPO), human neutrophil elastase (HNE), periostin, transforming growth factor-β1, total immunoglobulin E (IgE), and staphylococcal enterotoxin (SE)-specific IgE. We performed hierarchical cluster analysis and evaluated the phenotype, comorbidities, and Lund-Mackay computed tomography (LM CT) score in each cluster.

RESULTS

Five clusters and 3 endotypes were extracted from 244 CRS patients: cluster 1 had no upregulated mediators compared to the other clusters (mild mixed inflammatory CRS); clusters 2, 3, and 4 had higher concentrations of neutrophil-associated mediators including HNE, IL-8, IL-17A, and MPO (T3 CRS); and cluster 5 had higher levels of eosinophil-associated mediators (T2 CRS). SE-specific IgE was undetectable in T3 CRS and had low detectable levels (6.2%) even in T2 CRS. The CRS with nasal polyps (CRSwNP) phenotype and LM CT scores showed no significant differences between T2 and T3 CRS, while the incidence of comorbid asthma was higher in T2 CRS than T3 CRS. In T3 clusters, higher levels of neutrophilic markers were associated with disease severity and CRSwNP phenotype.

CONCLUSIONS

In Koreans, there is a distinct T3 CRS endotype showing a high proportion of CRSwNP and severe disease extent, along with T2 CRS.

Protective effects of cell permeable Tat-PIM2 protein on oxidative stress induced dopaminergic neuronal cell death

Background

Oxidative stress is considered as one of the main causes of Parkinson's disease (PD), however the exact etiology of PD is still unknown. Although it is known that Proviral Integration Moloney-2 (PIM2) promotes cell survival by its ability to inhibit formation of reactive oxygen species (ROS) in the brain, the precise functional role of PIM2 in PD has not been fully studied yet.

Objective

We investigated the protective effect of PIM2 against apoptosis of dopaminergic neuronal cells caused by oxidative stress-induced ROS damage by using the cell permeable Tat-PIM2 fusion protein in vitro and in vivo.

Methods

Transduction of Tat-PIM2 into SH-SY5Y cells and apoptotic signaling pathways were determined by Western blot analysis. Intracellular ROS production and DNA damage was confirmed by DCF-DA and TUNEL staining. Cell viability was determined by MTT assay. PD animal model was induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and protective effects were examined using immunohistochemistry.

Results

Transduced Tat-PIM2 inhibited the apoptotic caspase signaling and reduced the production of ROS induced by 1-methyl-4-phenylpyridinium (MPP⁺) in SH-SY5Y cells. Furthermore, we confirmed that Tat-PIM2 transduced into the substantia nigra (SN) region through the blood-brain barrier and this protein protected the Tyrosine hydroxylase-positive cells by observation of immunohistostaining. Tat-PIM2 also regulated antioxidant biomolecules such as SOD1, catalase, 4-HNE, and 8-OHdG which reduce the formation of ROS in the MPTP-induced PD mouse model.

Conclusion

These results indicated that Tat-PIM2 markedly inhibited the loss of dopaminergic neurons by reducing ROS damage, suggesting that Tat-PIM2 might be a suitable therapeutic agent for PD.

Association between Systemic Inflammatory Markers Based on Blood Cells and Polysomnographic Factors in Obstructive Sleep Apnea

Objectives

Systemic inflammation plays a key role in the pathogenesis of obstructive sleep apnea (OSA); however, methods to easily evaluate the severity of systemic inflammation are yet to be developed. This study aimed to analyze the association between systemic inflammation markers, which could be derived from the complete blood count (CBC) profile, and sleep parameters in a large number of patients with OSA.

Methods

Patients who visited our hospital's Otorhinolaryngology Sleep Clinic between January 2017 and February 2022 underwent polysomnography and routine laboratory tests, including CBC. Associations between three systemic inflammatory markers, systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR), and polysomnographic and demographic factors including age, sex, body mass index, apnea-hypopnea index (AHI), hypopnea index (HI), lowest oxygen saturation (%), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and percentages of non-Rapid Eye Movement (REM) sleep stage 3, REM sleep, and snoring time were analyzed. The inflammation markers of different OSA subgroups were also compared. The association was also analyzed in subgroups with different OSA severities.

Results

A total of 1102 (984 male, 134 female) patients were included, and their mean age was 46.70 ± 13.15 + mean AHI. PSQI (p = 0.027) was significantly associated with SII. There were no significant independent factors for the NLR and PLR. Within the simple snorer and mild OSA subgroups, there was no significant association between sleep parameters and the SII. In the severe OSA subgroup, AHI (p=0.004) and PSQI (p=0.012) were independently associated with SII.

Conclusion

Our study analyzed systemic inflammatory markers based on a simple, relatively cost-effective test, complete blood count, and showed that AHI and SII were significantly correlated only in the severe OSA subgroup.

Tat-Thioredoxin-like protein 1 attenuates ischemic brain injury by regulation of MAPKs and apoptosis signaling

Thioredoxin-like protein 1 (TXNL1), one of the thioredoxin superfamily known as redox-regulator, plays an essential in maintaining cell survival via various antioxidant and anti-apoptotic mechanisms. It is well known that relationship between ischemia and oxidative stress, however, the role of TXNL1 protein in ischemic damage has not been fully investigated. In the present study, we aimed to determine the protective role of TXNL1 against on ischemic injury in vitro and in vivo using cell permeable Tat-TXNL1 fusion protein. Transduced Tat-TXNL1 inhibited ROS production and cell death in H₂O₂-exposed hippocampal neuronal (HT-22) cells and modulated MAPKs and Akt activation, and pro-apoptotic protein expression levels in the cells. In an ischemia animal model, Tat-TXNL1 markedly decreased hippocampal neuronal cell death and the activation of astrocytes and microglia. These findings indicate that cell permeable Tat-TXNL1 protects against oxidative stress in vitro and in vivo ischemic animal model. Therefore, we suggest Tat-TXNL1 can be a potential therapeutic protein for ischemic injury.

MiR-30a-5p and miR-153-3p regulate LPS-induced neuroinflammatory response and neuronal apoptosis by targeting NeuroD1

Neurogenic differentiation 1 (NeuroD1) is an essential transcription factor for neuronal differentiation, maturation, and survival, and is associated with inflammation in lipopolysaccharide (LPS)-induced glial cells; however, the concrete mechanisms are still ambiguous. Therefore, we investigated whether NeuroD1-targeting miRNAs affect inflammation and neuronal apoptosis, as well as the underlying mechanism. First, we confirmed that miR-30a-5p and miR-153-3p, which target NeuroD1, reduced NeuroD1 expression in microglia and astrocytes. In LPS-induced microglia, miR-30a-5p and miR-153-3p suppressed pro-inflammatory cytokines, reactive oxygen species, the phosphorylation of c-Jun N-terminal kinase, extracellular-signal-regulated kinase (ERK), and p38, and the expression of cyclooxygenase and inducible nitric oxide synthase (iNOS) via the NF-κB pathway. Moreover, miR-30a-5p and miR-153-3p inhibited the expression of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, NLRP3, cleaved caspase-1, and IL-1β, which are involved in the innate immune response. In LPS-induced astrocytes, miR-30a-5p and miR-153-3p reduced ERK phosphorylation and iNOS expression via the STAT-3 pathway. Notably, miR-30a-5p exerted greater anti-inflammatory effects than miR-153-3p. Together, these results indicate that miR-30a-5p and miR-153-3p inhibit MAPK/NF-κB pathway in microglia as well as ERK/STAT-3 pathway in astrocytes to reduce LPS-induced neuronal apoptosis. This study highlights the importance of NeuroD1 in microglia and astrocytes neuroinflammation and suggests that it can be regulated by miR-30a-5p and miR-153-3p.

MiR-30a-5p and miR-153-3p regulate LPS-induced neuroinflammatory response and neuronal apoptosis by targeting NeuroD1

Neurogenic differentiation 1 (NeuroD1) is an essential transcription factor for neuronal differentiation, maturation, and survival, and is associated with inflammation in lipopolysaccharide (LPS)- induced glial cells; however, the concrete mechanisms are still ambiguous. Therefore, we investigated whether NeuroD1-targeting miRNAs affect inflammation and neuronal apoptosis, as well as the underlying mechanism. First, we confirmed that miR-30a-5p and miR-153-3p, which target NeuroD1, reduced NeuroD1 expression in microglia and astrocytes. In LPS-induced microglia, miR-30a-5p and miR-153-3p suppressed pro-inflammatory cytokines, reactive oxygen species, the phosphorylation of c-Jun N-terminal kinase, extracellular-signal-regulated kinase (ERK), and p38, and the expression of cyclooxygenase and inducible nitric oxide synthase (iNOS) via the NF-κB pathway. Moreover, miR-30a-5p and miR-153-3p inhibited the expression of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, NLRP3, cleaved caspase-1, and IL-1β, which are involved in the innate immune response. In LPS-induced astrocytes, miR-30a-5p and miR-153-3p reduced ERK phosphorylation and iNOS expression via the STAT-3 pathway. Notably, miR-30a-5p exerted greater anti-inflammatory effects than miR-153-3p. Together, these results indicate that miR-30a-5p and miR-153-3p inhibit MAPK/NF-κB pathway in microglia as well as ERK/STAT-3 pathway in astrocytes to reduce LPS-induced neuronal apoptosis. This study highlights the importance of NeuroD1 in microglia and astrocytes neuroinflammation and suggests that it can be regulated by miR-30a-5p and miR-153-3p. [BMB Reports 2022; 55(9): 447-452].

Aggressive Treatment Including Endonasal Surgical Sequestrectomy with Vascularized Nasoseptal Flap Can Improve Outcomes of Skull Base Osteoradionecrosis

Objective Skull base osteoradionecrosis (SB-ORN) is a serious, potentially lethal complication of radiation therapy. We aimed to review the clinical characteristics and outcomes of SB-ORN according to the extent of treatment.

Design Retrospective analysis design was used for this study.

Setting The study was conducted in two tertiary care hospitals.

Participants Patients included who had been clinically diagnosed with SB-ORN from January 2006 to 2017.

Main Outcome Measures Clinical characteristics, including demographics, predisposing factors, presenting symptoms, radiological findings, treatment modalities, and treatment outcomes, were reviewed. Treatment was classified into conservative and aggressive types. Aggressive treatment included radical surgical removal of soft tissue and bony sequestrum with the placement of vascularized tissue. Treatment outcome was analyzed in terms of clinical control, survival, and carotid artery blow out.

Results Fifteen patients (11 males and 4 females) were identified during the study period. Eight patients were managed conservatively, whereas seven patients were managed with aggressive treatment. The 2-year survival was 75% in the aggressive treatment group and 15% in the conservative group (log-rank, p = 0.049). The estimated 2-year blow out free rate was 46.7% for the conservative group and 100% for the aggressive group (log-rank, p = 0.100).

Conclusion In patients with SB-ORN, aggressive management, including surgical removal of sequestrum and coverage with a pedicled flap, is associated with increased survival.

Evaluating Prediction Models of Sleep Apnea From Smartphone-Recorded Sleep Breathing Sounds

Importance

Breathing sounds during sleep are an important characteristic feature of obstructive sleep apnea (OSA) and have been regarded as a potential biomarker. Breathing sounds during sleep can be easily recorded using a microphone, which is found in most smartphone devices. Therefore, it may be easy to implement an evaluation tool for prescreening purposes.

Objective

To evaluate OSA prediction models using smartphone-recorded sounds and identify optimal settings with regard to noise processing and sound feature selection.

Design, Setting, and Participants

A cross-sectional study was performed among patients who visited the sleep center of Seoul National University Bundang Hospital for snoring or sleep apnea from August 2015 to August 2019. Audio recordings during sleep were performed using a smartphone during routine, full-night, in-laboratory polysomnography. Using a random forest algorithm, binary classifications were separately conducted for 3 different threshold criteria according to an apnea hypopnea index (AHI) threshold of 5, 15, or 30 events/h. Four regression models were created according to noise reduction and feature selection from the input sound to predict actual AHI: (1) noise reduction without feature selection, (2) noise reduction with feature selection, (3) neither noise reduction nor feature selection, and (4) feature selection without noise reduction. Clinical and polysomnographic parameters that may have been associated with errors were assessed. Data were analyzed from September 2019 to September 2020.

Main Outcomes and Measures

Accuracy of OSA prediction models.

Results

A total of 423 patients (mean [SD] age, 48.1 [12.8] years; 356 [84.1%] male) were analyzed. Data were split into training (n = 256 [60.5%]) and test data sets (n = 167 [39.5%]). Accuracies were 88.2%, 82.3%, and 81.7%, and the areas under curve were 0.90, 0.89, and 0.90 for an AHI threshold of 5, 15, and 30 events/h, respectively. In the regression analysis, using recorded sounds that had not been denoised and had only selected attributes resulted in the highest correlation coefficient (r = 0.78; 95% CI, 0.69-0.88). The AHI (β = 0.33; 95% CI, 0.24-0.42) and sleep efficiency (β = -0.20; 95% CI, -0.35 to -0.05) were found to be associated with estimation error.

Conclusions and Relevance

In this cross-sectional study, recorded sleep breathing sounds using a smartphone were used to create reasonably accurate OSA prediction models. Future research should focus on real-life recordings using various smartphone devices.

Definition of the snoring episode index based on the analyses of snoring parameters and the apnea hypopnea index

Although snoring is the most common subjective symptom in obstructive sleep apnea (OSA), an international consensus on the definition of snoring is lacking. This study aimed to define snoring by analyzing correlations between snoring parameters and the apnea hypopnea index (AHI). We retrospectively analyzed the polysomnography data of patients with OSA. A snoring event was defined when airflow pressure was > 200 microbar. We included four snoring parameters. Snoring percentage was defined as the cumulative time of snoring events divided by total sleep time. A snoring episode was defined as the occurrence of ≥ 3 consecutive snoring events, and the snoring episode index was defined as the number of snoring episodes per hour. The average and longest durations of snoring episodes were also investigated. The study enrolled 5035 patients. Their mean AHI was 26.5/h and the mean snoring episode index was 19.2/h. Although the four snoring parameters showed significant correlations with the AHI, the snoring episode index showed the strongest positive correlation with the AHI (r = 0.741, P < 0.001). The snoring episode index may be used as a definition of snoring from the perspective of a highly positive correlation with the AHI.

Cerebellar dysfunction and schizophrenia-like behavior in Ebp1-deficient mice

Cerebellar deficits with Purkinje cell (PCs) loss are observed in several neurologic disorders. However, the underlying mechanisms as to how the cerebellum is affected during development remain unclear. Here we demonstrated that specific inactivation of murine Ebp1 in the central nervous system causes a profound neuropathology characterized by reduced cerebellar volume and PCs loss with abnormal dendritic development, leading to phenotypes including motor defects and schizophrenia (SZ)-like behaviors. Loss of Ebp1 leads to untimely gene expression of Fbxw7, an E3 ubiquitin ligase, resulting in aberrant protein degradation of PTF1A, thereby eliciting cerebellar defects. Reinstatement of Ebp1, but not the Ebp1-E183Ter mutant found in SZ patients, reconstituted cerebellar architecture with increased PCs numbers and improved behavioral phenotypes. Thus, our findings indicate a crucial role for EBP1 in cerebellar development, and define a molecular basis for the cerebellar contribution to neurologic disorders such as SZ.

Prediction of Oxygen Desaturation by Using Sound Data From a Noncontact Device: A Proof-of-Concept Study

OBJECTIVES/HYPOTHESIS

Prediction of the apnea-hypopnea index (AHI) from breathing sounds during sleep could be used to prescreen for obstructive sleep apnea (OSA). In addition, the oxygen desaturation index (ODI) is a known risk factor for developing cardiovascular disease in OSA patients. This study focused on estimation of ODI from a noncontact manner from sleep breathing sounds.

STUDY DESIGN

Retrospective study.

METHODS

Patients who visited the sleep center due to snoring or sleep apnea underwent polysomnography in lab overnight. Sound recordings were made during polysomnography using a microphone. After noise reduction, the sound data were segmented into 5 seconds windows and features were extracted. Binary classification and regression analyses were performed to estimate the ODI during sleep (model 1). This was re-tested after inclusion of body mass index (BMI) and age as additional features (model 2: BMI only, model 3: BMI and age).

RESULTS

We included 116 patients. The mean age and AHI of all patients were 50.4 ± 16.7 years and 23.0 ± 24.0 events/hr. In binary classification, for ODI cutoff values of 5, 15, and 30 events/hr, the areas under the curve were 0.88, 0.93, 0.91, respectively, and accuracies were 85.34, 86.21, and 87.07, respectively. In regression analysis, the correlation coefficient and mean absolute error were 0.80 and 9.60 events/hr, respectively. In models 2 and 3, the correlation coefficient and mean absolute error were 0.82, 9.44 events/hr and 0.81, 9.6 events/hr, respectively.

CONCLUSION

Prediction of ODI from sleep sound seems to be feasible. Additional clinical feature such as BMI may increase overall predictability.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Anti-inflammatory effects of N-cyclooctyl-5-methylthiazol-2-amine hydrobromide on lipopolysaccharide-induced inflammatory response through attenuation of NLRP3 activation in microglial cells

Microglial activation is closely associated with neuroinflammatory pathologies. The nucleotide-binding and oligomerization domain-like receptor containing a pyrin domain 3 (NLRP3) inflammasomes are highly organized intracellular sensors of neuronal alarm signaling. NLRP3 inflammasomes activate nuclear factor kappa-B (NF-κB) and reactive oxygen species (ROS), which induce inflammatory responses. Moreover, NLRP3 dysfunction is a common feature of chronic inflammatory diseases. The present study investigated the effect of a novel thiazol derivative, N-cyclooctyl-5-methylthiazol-2-amine hydrobromide (KHG26700), on inflammatory responses in lipopolysaccharide (LPS)-treated BV-2 microglial cells. KHG26700 significantly attenuated the expression of several pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and interleukin-6, in these cells, as well as the LPS-induced increases in NLRP3, NF-κB, and phospho-IkBα levels. KHG26700 also suppressed the LPS-induced increases in protein levels of autophagy protein 5 (ATG5), microtubule-associated protein 1 light chain 3 (LC3), and beclin-1, as well as downregulating the LPS-enhanced levels of ROS, lipid peroxidation, and nitric oxide. These results suggest that the anti-inflammatory effects of KHG26700 may be due, at least in part, to the regulation of the NLRP3-mediated signaling pathway during microglial activation.

Inhibitor of DNA binding 2 (Id2) mediates microtubule polymerization in the brain by regulating αK40 acetylation of α-tubulin

Acetylation of α-tubulin lysine 40 (αK40) contributes to microtubule (MT) stability and is essential for neuronal development and function, whereas excessive αK40 deacetylation is observed in neurodegenerative disorders including Alzheimer’s disease (AD). Here we identified inhibitor of DNA binding 2 (Id2) as a novel MT-binding partner that interacts with α-tubulin and enhances αK40 acetylation, leading to MT polymerization in the neurons. Commensurate with our finding that the low levels of Id2 expression along with a reduced αK40 acetylation in the postmortem human AD patient and 5X-FAD, AD model mice brain, Id2 upregulation in the hippocampus of 5X-FAD, which exhibit high levels of Sirt2 expression, increased αK40 acetylation and reconstitutes axon growth. Hence our study suggests that Id2 is critical for maintaining MT stability during neural development and the potential of Id2 to counteract pathogenic Sirt2 activity in AD.

EBP1 regulates Suv39H1 stability via the ubiquitin-proteasome system in neural development

ErbB3-binding protein 1 (EBP1) is a multifunctional protein associated with neural development. Loss of Ebp1 leads to upregulation of the gene silencing unit suppressor of variegation 3-9 homolog 1 (Suv39H1)/DNA (cytosine 5)-methyltransferase (DNMT1). EBP1 directly binds to the promoter region of DNMT1, repressing DNA methylation, and hence, promoting neural development. In the current study, we showed that EBP1 suppresses histone methyltransferase activity of Suv39H1 by promoting ubiquitin-proteasome system (UPS)-dependent degradation of Suv39H1. In addition, we showed that EBP1 directly interacts with Suv39H1, and this interaction is required for recruiting the E3 ligase MDM2 for Suv39H1 degradation. Thus, our findings suggest that EBP1 regulates UPS-dependent degradation of Suv39H1 to govern proper heterochromatin assembly during neural development.

Transduced Tat-PRAS40 prevents dopaminergic neuronal cell death through ROS inhibition and interaction with 14-3-3σ protein

Proline rich Akt substrate (PRAS40) is a component of mammalian target of rapamycin complex 1 (mTORC1) and activated mTORC1 plays important roles for cellular survival in response to oxidative stress. However, the roles of PRAS40 in dopaminergic neuronal cell death have not yet been examined. Here, we examined the roles of Tat-PRAS40 in MPP⁺- and MPTP-induced dopaminergic neuronal cell death. Our results showed that Tat-PRAS40 effectively transduced into SH-SY5Y cells and inhibited DNA damage, ROS generation, and apoptotic signaling in MPP⁺-induced SH-SY5Y cells. Further, these protective mechanisms of Tat-PRAS40 protein display through phosphorylation of Tat-PRAS40, Akt and direct interaction with 14-3-3σ protein, but not via the mTOR-dependent signaling pathway. In a Parkinson's disease animal model, Tat-PRAS40 transduced into dopaminergic neurons in mouse brain and significantly protected against dopaminergic cell death by phosphorylation of Tat-PRAS40, Akt and interaction with 14-3-3σ protein. In this study, we demonstrated for the first time that Tat-PRAS40 directly protects against dopaminergic neuronal cell death. These results indicate that Tat-PRAS40 may provide a useful therapeutic agent against oxidative stress-induced dopaminergic neuronal cell death, which causes diseases such as PD.

Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements

We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of sqrt[s]=1.96  TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.

Protective Role of Transduced Tat-Thioredoxin1 (Trx1) against Oxidative Stress-Induced Neuronal Cell Death via ASK1-MAPK Signal Pathway

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H₂O₂-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

Preferential Expression of Programmed Death Ligand 1 Protein in Tumor-Associated Macrophages and Its Potential Role in Immunotherapy for Hepatocellular Carcinoma

A predictive biomarker of immune checkpoint inhibitor (ICI)-based treatments in hepatocellular carcinoma (HCC) has not been clearly demonstrated. In this study, we focused on the infiltration and programmed death ligand 1 (PD-L1) expression of tumor-associated macrophages (TAMs) in the tumor microenvironment of HCC. Immunohistochemistry demonstrated that PD-L1 was preferentially expressed on CD68+ macrophages in the tumor microenvironment of HCC, suggestive of its expression in TAMs rather than in T cells or tumor cells (P < 0.05). A co-culture experiment using activated T cells and M2 macrophages confirmed a significant increase in T cell functionality after the pretreatment of M2 macrophages with anti-PD-L1. Syngeneic mouse model experiments demonstrated that TAMs expressed PD-L1 and tumors treated with anti-PD-L1 showed smaller diameters than those treated with IgG. In these mice, anti-PD-L1 treatment increased activation markers in intratumoral CD8+ T cells and reduced the size of the TAM population. Regarding nivolumab-treated patients, three of eight patients responded to the anti-PD-1 treatment. The percentage of Ki-67-positive CD4+ and CD8+ T cells was higher in responders than non-responders after nivolumab. Overall, PD-L1 expression on TAMs may be targeted by immune-based HCC treatment, and ICI treatment results in the reinvigoration of exhausted CD8+ T cells in HCC.

Microbiome profiling of uncinate tissue and nasal polyps in patients with chronic rhinosinusitis using swab and tissue biopsy

Chronic rhinosinusitis (CRS) is characterized according to the presence or absence of nasal polyps (NPs) and displays nasal microbiota dysbiosis. However, optimal sampling methods of the nasal microbiome in CRS have not been identified. We aimed to assess the microbial composition in patients with CRS, comparing different sampling methods (swab and tissue biopsy), tissue types (uncinate tissue and NP), and disease subtypes. Samples were obtained by swabbing the middle meatus and taking a biopsy of uncinate tissue (UT) in patients with CRS with (CRSwNP, N = 8) or without NP (CRSsNP, N = 6) and controls (N = 8). NPs were also harvested in CRSwNP. DNAs were extracted from fifty-two samples and analyzed by 16S rRNA gene amplicon sequencing. As a result, a great interpersonal variance was observed in nasal swabs, while UT samples presented distinct microbiome with low inter-personal differences. Moreover, the UT microbiomes were further differentiated into three clusters which are associated with disease status (control, CRSsNP, and CRSwNP). Compared to UT, NP revealed a unique microbiome profile with significantly less bacterial diversity. Prevotella was the genus whose abundance was negatively correlated with disease severity in NP. In conclusion, tissue samples are better specimens than nasal swabs for assessing the microbiomes of CRS patients. Several bacteria in UT and NP tissues revealed an association with clinical severity of CRSwNP.

Development of HIGH-INTENSITY FOCUSED ULTRASOUND(HIFU) Therapy in Inferior Turbinate Hypertrophy

Objectives

Inferior turbinate (IT) hypertrophy is the main cause of chronic nasal obstruction. We developed a high-intensity focused ultrasound (HIFU) ablation device to treat patients with IT hypertrophy.

Methods

First, computed tomography images of patients with no evidence of sinonasal disease were evaluated to measure and compare the IT, medial mucosal thickness (MT), and space between the nasal septum and IT according to clinical characteristics such as septal deviation. A HIFU prototype was developed based on the above human anatomical studies. The experimental study was performed in five pigs; the nasal volume and histological changes at 1 and 4 weeks postoperatively were evaluated to compare the efficacy of HIFU turbinoplasty with that of radiofrequency turbinoplasty and a control group.

Results

The mean medial MT of the anterior, middle, and posterior portions of the IT were 4.66±1.14, 4.23±0.97, and 6.17±1.29 mm, respectively. The mean medial space was 2.65±0.79 mm. The diameter and focal depth of the prototype were 4 mm and 3 mm, respectively. HIFU showed no postoperative complications, including bleeding or scar formation. After HIFU treatment, the nasal volume increased by 196.62 mm³ (7.8%) and 193.74 mm³ (8.3%) at 1 week and 4 weeks, compared with the increase of 87.20 mm³ (3.1%) and 213.81 mm³ (9.0%), respectively,after radiofrequency therapy. A qualitative histological analysis after radiofrequency turbinoplasty showed epithelial layer disruption at 1 week and increased fibrosis, along with decreased glandular structure, at 4 weeks. The HIFU group had an intact epithelial layer at 1 week postoperatively. However, significant differences were observed at 4 weeks, including increased fibrosis and decreased glandular structure.

Conclusion

The efficacy and safety of HIFU turbinoplasty were demonstrated in an animal study. Our results warrant further human clinical trials.

Combined unsupervised-supervised machine learning for phenotyping complex diseases with its application to obstructive sleep apnea

Unsupervised clustering models have been widely used for multimetric phenotyping of complex and heterogeneous diseases such as diabetes and obstructive sleep apnea (OSA) to more precisely characterize the disease beyond simplistic conventional diagnosis standards. However, the number of clusters and key phenotypic features have been subjectively selected, reducing the reliability of the phenotyping results. Here, to minimize such subjective decisions for highly confident phenotyping, we develop a multimetric phenotyping framework by combining supervised and unsupervised machine learning. This clusters 2277 OSA patients to six phenotypes based on their multidimensional polysomnography (PSG) data. Importantly, these new phenotypes show statistically different comorbidity development for OSA-related cardio-neuro-metabolic diseases, unlike the conventional single-metric apnea–hypopnea index-based phenotypes. Furthermore, the key features of highly comorbid phenotypes were identified through supervised learning rather than subjective choice. These results can also be used to automatically phenotype new patients and predict their comorbidity risks solely based on their PSG data. The phenotyping framework based on the combination of unsupervised and supervised machine learning methods can also be applied to other complex, heterogeneous diseases for phenotyping patients and identifying important features for high-risk phenotypes.

Hypoxia-Induced S100A8 Expression Activates Microglial Inflammation and Promotes Neuronal Apoptosis

S100 calcium-binding protein A8 (S100A8), a danger-associated molecular pattern, has emerged as an important mediator of the pro-inflammatory response. Some S100 proteins play a prominent role in neuroinflammatory disorders and increase the secretion of pro-inflammatory cytokines in microglial cells. The aim of this study was to determine whether S100A8 induced neuronal apoptosis during cerebral hypoxia and elucidate its mechanism of action. In this study, we reported that the S100A8 protein expression was increased in mouse neuronal and microglial cells when exposed to hypoxia, and induced neuroinflammation and neuronal apoptosis. S100A8, secreted from neurons under hypoxia, activated the secretion of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) through phosphorylation of extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) in microglia. Also, phosphorylation of ERK via the TLR4 receptor induced the priming of the NLRP3 inflammasome. The changes in Cyclooxygenase-2 (COX-2) expression, a well-known inflammatory activator, were regulated by the S100A8 expression in microglial cells. Knockdown of S100A8 levels by using shRNA revealed that microglial S100A8 expression activated COX-2 expression, leading to neuronal apoptosis under hypoxia. These results suggested that S100A8 may be an important molecule for bidirectional microglia-neuron communication and a new therapeutic target for neurological disorders caused by microglial inflammation during hypoxia.

Tat‑aldose reductase prevents dopaminergic neuronal cell death by inhibiting oxidative stress and MAPK activation

Aldose reductase (AR) is known to detoxify aldehydes and prevent oxidative stress. Although AR exerts antioxidant effects, the role of AR in Parkinson's disease (PD) remains unclear. The objective of the present study was to investigate the protective effects of AR protein against 1‑methyl‑4‑phenylpyridinium (MPP+)‑induced SH‑SY5Y cell death and 1‑methyl‑4‑phenyl‑1,2,3,6‑tetrahydropyridine (MPTP)‑induced PD in a mouse model using the cell permeable Tat‑AR fusion protein. The results revealed that when Tat‑AR protein was transduced into SH‑SY5Y cells, it markedly protected the cells against MPP+‑induced death and DNA fragmentation. It also reduced the activation of mitogen-activated protein kinase (MAPKs) and regulated the expression levels of Bcl‑2, Bax and caspase‑3. Immunohistochemical analysis revealed that when Tat‑AR protein was transduced into the substantia nigra (SN) of mice with PD, it markedly inhibited dopaminergic neuronal cell death. Therefore, Tat‑AR may be useful as a therapeutic protein for PD.

Tat-indoleamine 2,3-dioxygenase 1 elicits neuroprotective effects on ischemic injury

It is well known that oxidative stress participates in neuronal cell death caused production of reactive oxygen species (ROS). The increased ROS is a major contributor to the development of ischemic injury. Indoleamine 2,3-dioxygenase 1 (IDO-1) is involved in the kynurenine pathway in tryptophan metabolism and plays a role as an anti-oxidant. However, whether IDO-1 would inhibit hippocampal cell death is poorly known. Therefore, we explored the effects of cell permeable Tat-IDO-1 protein against oxidative stress-induced HT-22 cells and in a cerebral ischemia/reperfusion injury model. Transduced Tat-IDO-1 reduced cell death, ROS production, and DNA fragmentation and inhibited mitogen-activated protein kinases (MAPKs) activation in H₂O₂ exposed HT-22 cells. In the cerebral ischemia/reperfusion injury model, Tat-IDO-1 transduced into the brain and passing by means of the blood-brain barrier (BBB) significantly prevented hippocampal neuronal cell death. These results suggest that Tat-IDO-1 may present an alternative strategy to improve from the ischemic injury.

N-Adamantyl-4-methylthiazol-2-amine suppresses glutamate-induced autophagic cell death via PI3K/Akt/mTOR signaling pathways in cortical neurons

We recently reported that N-adamantyl-4-methylthiazol-2-amine (KHG26693) attenuates glutamate-induced oxidative stress and inflammation in the brain. In this study, we investigated KHG 26693 as a therapeutic agent against glutamate-induced autophagic death of cortical neurons. Treatment with KHG26693 alone did not affect the viability of cultured cortical neurons but was protective against glutamate-induced cytotoxicity in a concentration-dependent manner. KHG26693 attenuated the glutamate-induced increase in protein levels of LC3, beclin-1, and p62. Whereas glutamate decreased the phosphorylation of PI3K, Akt, and mTOR, these levels were restored by treatment with KHG26693. These results suggest that KHG26693 inhibits glutamate-induced autophagy by regulating PI3K/Akt/mTOR signaling. Finally, KHG26693 treatment also attenuated glutamate-induced increases in reactive oxygen species, glutathione, glutathione peroxidase, and superoxide dismutase levels in cortical neurons, indicating that KHG26693 also protects cortical neurons against glutamate-induced autophagy by regulating the reactive oxygen species scavenging system.

Effects of α-lipoic acid on LPS-induced neuroinflammation and NLRP3 inflammasome activation through the regulation of BV-2 microglial cells activation

Microglial cells are known as the main immune cells in the central nervous system, both regulating its immune response and maintaining its homeostasis. Furthermore, the antioxidant α-lipoic acid (LA) is a recognized therapeutic drug for diabetes because it can easily invade the blood–brain barrier. This study investigated the effect of α-LA on the inflammatory response in lipopolysaccharide (LPS)-treated BV-2 microglial cells. Our results revealed that α-LA significantly attenuated several inflammatory responses in BV-2 microglial cells, including pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin (IL)-6, and other cytotoxic molecules, such as nitric oxide and reactive oxygen species. In addition, α-LA inhibited the LPS-induced phosphorylation of ERK and p38 and its pharmacological properties were facilitated via the inhibition of the nuclear factor kappa B signaling pathway. Moreover, α-LA suppressed the activation of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, multiprotein complexes consisting of NLRP3 and caspase-1, which are involved in the innate immune response. Finally, α-LA decreased the genes accountable for the M1 phenotype, IL-1β and ICAM1, whereas it increased the genes responsible for the M2 phenotype, MRC1 and ARG1. These findings suggest that α-LA alleviates the neuroinflammatory response by regulating microglial polarization.

Prediction of Apnea-Hypopnea Index Using Sound Data Collected by a Noncontact Device

OBJECTIVE

To predict the apnea-hypopnea index (AHI) in patients with obstructive sleep apnea (OSA) using data from breathing sounds recorded using a noncontact device during sleep.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral hospital.

SUBJECT AND METHODS

Audio recordings during sleep were performed using an air-conduction microphone during polysomnography. Breathing sounds recorded from all sleep stages were analyzed. After noise reduction preprocessing, the audio data were segmented into 5-second windows and sound features were extracted. Estimation of AHI by regression analysis was performed using a Gaussian process, support vector machine, random forest, and simple linear regression, along with 10-fold cross-validation.

RESULTS

In total, 116 patients who underwent attended, in-laboratory, full-night polysomnography were included. Overall, random forest resulted in the highest performance with the highest correlation coefficient (0.83) and least mean absolute error (9.64 events/h) and root mean squared error (13.72 events/h). Other models resulted in somewhat lower but similar performances, with correlation coefficients ranging from 0.74 to 0.79. The estimated AHI tended to be underestimated as the severity of OSA increased. Regarding bias and precision, estimation performances in the severe OSA subgroup were the lowest, regardless of the model used. Among sound features, derivative of the area methods of moments of overall standard deviation demonstrated the highest correlation with AHI.

CONCLUSION

AHI was fairly predictable by using data from breathing sounds generated during sleep. The prediction model may be useful not only for prescreening but also for follow-up after treatment in patients with OSA.

Clinical Characteristics Other Than Intralesional Hyperdensity May Increase the Preoperative Diagnostic Accuracy of Maxillary Sinus Fungal Ball

Objectives

This study aimed to evaluate the clinical characteristics of maxillary sinus fungus ball (MFB) to increase the preoperative diagnostic accuracy.

Methods

A retrospective review of 247 patients who underwent endoscopic sinus surgery for unilateral maxillary sinusitis from January 2015 to December 2017 at a single institution was performed. Patients with pathologically proven MFB were compared to those with unilateral chronic maxillary sinusitis (CMS). Patient demographics and computed tomography (CT) findings were evaluated. The CT features were categorized as intralesional hyperdensity (calcification), the irregular lobulated protruding lesion (fuzzy appearance), maxillary sinus full haziness without mass effect, maxillary sinus full haziness with mass effect, and others. A regression tree analysis was performed.

Results

In total, 247 patients were analyzed; among them, 179 (72.5%) had MFB and 68 (27.5%) had CMS. MFB showed predominance in older individuals. Among the radiological features, intralesional hyperdensity was most commonly associated with MFB. The presence of a fuzzy appearance or full opacity with mass effect was also associated with MFB. The highest area under the curve was noted with the regression tree analysis based on the model, which included the presence of intralesional hyperdensity, demographic data (age), and presence of fuzzy appearance or maxillary sinus full haziness with mass effect in case of absence of intralesional hyperdensity (0.904).

Conclusion

A simple algorithm to optimize the preoperative diagnosis of MFB was developed. Physicians should be aware of such findings in the management of patients presenting with unilateral CMS.

Transduced Tat-aldose Reductase Protects Hippocampal Neuronal Cells against Oxidative Stress-induced Damage

Aldose reductase (AR) protein, a member of the NADPH-dependent aldo-keto reductase family, reduces a wide range of aldehydes and enhances cell survival by inhibition of oxidative stress. Oxidative stress is known as one of the major pathological factor in ischemia. Since the precise function of AR protein in ischemic injury is fully unclear, we examined the function of AR protein in hippocampal neuronal (HT-22) cells and in an animal model of ischemia in this study. Cell permeable Tat-AR protein was produced by fusion of protein transduction domain in Tat for delivery into the cells. Tat-AR protein transduced into HT-22 cells and significantly inhibited cell death and regulated the mitogen-activate protein kinases (MAPKs), Bcl-2, Bax, and Caspase-3 under oxidative stress condition. In an ischemic animal model, Tat-AR protein transduced into the brain tissues through the blood-brain barrier (BBB) and drastically decreased neuronal cell death in hippocampal CA1 region. These results indicate that transduced Tat-AR protein has protective effects against oxidative stress-induced neuronal cell death in vitro and in vivo, suggesting that Tat-AR protein could be used as potential therapeutic agent in ischemic injury.

Effects of α-lipoic acid on LPS-induced neuroinflammation and NLRP3 inflammasome activation through the regulation of BV-2 microglial cells activation

Microglial cells are known as the main immune cells in the central nervous system, both regulating its immune response and maintaining its homeostasis. Furthermore, the antioxidant α-lipoic acid (LA) is a recognized therapeutic drug for diabetes because it can easily invade the blood-brain barrier. This study investigated the effect of α-LA on the inflammatory response in lipopolysaccharide (LPS)-treated BV-2 microglial cells. Our results revealed that α-LA significantly attenuated several inflammatory responses in BV-2 microglial cells, including pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin (IL)-6, and other cytotoxic molecules, such as nitric oxide and reactive oxygen species. In addition, α-LA inhibited the LPS-induced phosphorylation of ERK and p38 and its pharmacological properties were facilitated via the inhibition of the nuclear factor kappa B signaling pathway. Moreover, α-LA suppressed the activation of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, multiprotein complexes consisting of NLRP3 and caspase-1, which are involved in the innate immune response. Finally, α-LA decreased the genes accountable for the M1 phenotype, IL-1β and ICAM1, whereas it increased the genes responsible for the M2 phenotype, MRC1 and ARG1. These findings suggest that α-LA alleviates the neuroinflammatory response by regulating microglial polarization. [BMB Reports 2019; 52(10): 613-618].

SIAH1 ubiquitin ligase mediates ubiquitination and degradation of Akt3 in neural development

Akt signaling is an important regulator of neural development, but the distinctive function of Akt isoforms in brain development presents a challenge. Here we show Siah1 as an ubiquitin ligase that preferentially interacts with Akt3 and facilitates ubiquitination and degradation of Akt3. Akt3 is enriched in the axonal shaft and branches but not growth cone tips, where Siah1 is prominently present. Depletion of Siah1 enhanced Akt3 levels in the soma and axonal tips, eliciting multiple branching. Brain-specific somatic mutation in Akt3-E17K escapes from Siah1-mediated degradation and causes improper neural development with dysmorphic neurons. Remarkably, coexpression of Siah1 with Akt3-WT restricted disorganization of neural development is caused by Akt3 overexpression, whereas forced expression of Siah1 with the Akt3-E17K mutant fails to cope with malformation of neural development. These findings demonstrate that Siah1 limits Akt3 turnover during brain development and that this event is essential for normal organization of the neural network.

Protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride on hypoxia-induced β-amyloid production in SH-SY5Y cells

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer’s disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced β-amyloid (Aβ) generation and development of AD is not yet known. We have now investigated the protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride (KHG26702), a novel thiazole derivative, on oxygen-glucose deprivation (OGD)-reoxygenation (OGD-R)-induced Aβ production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with KHG26702 significantly attenuated OGD-R-induced production of reactive oxygen species and elevation of levels of malondialdehyde, prostaglandin E₂, interleukin 6 and glutathione, as well as superoxide dismutase activity. KHG26702 also reduced OGD-R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, KHG26702 reduced OGD-R-induced Aβ production and cleavage of amyloid precursor protein, by inhibiting secretase activity and suppressing the autophagic pathway. Although supporting data from in vivo studies are required, our results indicate that KHG26702 may prevent neuronal cell damage from OGD-R-induced toxicity.

KHG21834 attenuates glutamate-induced mitochondrial damage, apoptosis, and NLRP3 inflammasome activation in SH-SY5Y human neuroblastoma cells

New compounds were screened to develop effective drugs against glutamate-induced toxicity. The present study assessed the effects of the novel thiazole derivative KHG21834 against glutamate-induced toxicity in human neuroblastoma SH-SY5Y cell cultures. Treatment of SH-SY5Y cells with KHG21834 significantly protected cells against glutamate-induced toxicity in a dose-dependent manner, with an optimum concentration of 50 μM. KHG21834 protected SH-SY5Y cells against glutamate toxicity by suppressing glutamate-induced oxidative stress by 50%. KHG21834 also attenuated glutamate-induced mitochondrial membrane potential, ATP level reductions, and intracellular Ca²⁺ influx. Furthermore, KHG21834 efficiently reduced glutamate-induced ER stress and NLRP3 inflammasome activation (59% and 65% of glutamate group, respectively). In addition, KHG21834 effectively attenuated glutamate-induced levels of Bax, Bcl-2, cleaved caspase-3, p-p38, p-JNK proteins, and TUNEL positive cells. To our knowledge, this is the first study showing that KHG21834 can effectively protect SH-SY5Y cells against glutamate toxicity, suggesting that this compound may be a valuable therapeutic agent for the treatment of glutamate toxicity.

Recovery period of sinonasal quality of life and its associated factors after endoscopic endonasal approach for anterior skull base tumors

BACKGROUND

Although endoscopic endonasal approach (EEA) for skull base tumors showed a good prognosis in sinonasal quality of life (QOL), what factors have influence on QOL is still in question. Aim/Objectives: To investigate the recovery of sinonasal QOL after EEA for anterior skull base tumors and find its prognostic factors.

MATERIAL AND METHODS

The study enrolled 250 patients undergoing EEA for anterior skull base tumors over 3 years. Sinonasal QOL was evaluated via sinonasal outcome test (SNOT-22) during 6 months. Age, gender, previous surgery, surgical extent, tumor pathology, combined surgical procedures, and surgical complications were analyzed.

RESULTS

There were 101 male and 149 female with average 48.6 ± 16.1 years old. SNOT-22 increased from baseline (median 17.0; Q₁-Q₃ 8.25-30.0) to postoperative 1 and 3 months (27.0; 15.0-36.0; p   <   .001 and 20.5; 11.0-32.0; p = .021, respectively) and it returned to the baseline within 6 months. Reconstruction with calcium hydroxyapatite and postoperative mucosal edema had a negative impact on the recovery (p  = .016 and .010, respectively), after adjustment for the baseline scores and postoperative months.

CONCLUSIONS AND SIGNIFICANCE

Sinonasal QOL was recovered within 6 months. Avoidance of calcium hydroxyapatite could prevent delayed recovery. Surgeons should carefully manipulate nasal mucosa to minimize postoperative mucosal edema.