The Usefulness of Respiratory Mechanic Instability in Evaluating the Effect of Continuous Positive Airway Pressure for Obstructive Sleep Apnea.

OBJECTIVES: Respiratory mechanics instability (RMI) based on paradoxical movement is correlated with respiratory disturbance such as apnea-hypopnea index (AHI) and reflects the severity of obstructive sleep apnea (OSA). The purpose of this study was to identify RMI as a method for assessing the effectiveness of continuous positive airway pressure (CPAP) in the management for OSA. METHODS: A total of 71 consecutive OSA patients with CPAP titration were included in this study. We compared sleep (sleep efficiency, arousal index, and sleep stages), respiratory (AHI, oxygen desaturation index ≥3% [ODI3], and lowest oxygen saturation), and RMI parameters (events, index, duration, and % of stage duration) between diagnostic polysomnography and CPAP titration data. RESULTS: All RMI parameters (events [157.5 ± 80.9 vs 80.0 ± 47.1; P < .001], index [25.3 ± 12.4 vs 12.7 ± 7.0; P < .001], duration [182.6 ± 96.2 vs 79.8 ± 88.9; P < .001], and % of stage duration [49.0 ± 24.4 vs 20.5 ± 21.3; P < .001]) were significantly improved by the alleviation of obstructive respiratory disturbance parameters (AHI [45.1 ± 23.0 vs 4.2 ± 4.3; P < .001], ODI3 [44.9 ± 22.6 vs 4.8 ± 4.6; P < .001], and lowest oxygen saturation [77.7 ± 7.3 vs 89.3 ± 3.8; P < .001]) compared to diagnostic polysomnography and CPAP titration data. CONCLUSION: RMI may be a useful method for evaluating the effect of CPAP in OSA patients.

Association of Respiratory Mechanic Instability and Respiratory Parameters among Adults with Obstructive Sleep Apnea.

OBJECTIVES: Respiratory mechanic instability (RMI) is derived from analysis of paradoxical thoracoabdominal movements during airway obstruction. This study aimed to evaluate RMI parameters in obstructive sleep apnea (OSA) and the correlation between RMI parameters and other parameters in polysomnography. STUDY DESIGN: Retrospective review. SETTING: A university hospital. METHODS: A retrospective chart review was performed, and data from 189 adult patients who underwent an in-laboratory sleep study and were seen in our clinic during the past 8 months. The RMI parameters were measured from thoracoabdominal bands during polysomnography. RESULTS: Subjects were divided into 2 groups: control (n = 67, apnea-hypopnea index [AHI] <5) and OSA (n = 122, AHI ≥5). The OSA group was divided into 3 subgroups according to AHI: mild, 5 ≤ AHI < 15; moderate, 15 ≤ AHI < 30; severe, AHI ≥30. As AHI increased, all RMI parameters showed a significant rising pattern and difference between control and subgroups. Arousal index, lowest oxygen saturation, and oxygen desaturation index ≥3% were significantly correlated with all RMI parameters. Based on cutoff values, areas under the curves of the RMI index for predicting mild, moderate, and severe OSA were >0.85. CONCLUSION: All RMI parameters were well related to respiratory parameters of polysomnography, such as arousal index, lowest oxygen saturation, and oxygen desaturation index ≥3%. The areas under the curves of all RMI parameters for predicting OSA and subgroups showed significant diagnostic performance. These parameters may be useful to identify OSA cases from control.

In vivo evidence on the functional variation within fatty acid synthase gene associated with lipid metabolism in bovine longissimus dorsi muscle tissue.

In Korean cattle, intramuscular fat (IMF), or marbling, of the longissimus dorsi muscle (LM) cross section is one of the most important indicators of beef quality and are influenced by environmental and genetic factors. This study was to evaluate the effect of SNPs on the beef quality in Korean cattle for functional studies, such as site-directed mutagenesis based on bovine adipocytes. The fatty acid synthase (FASN) gene plays an important role in lipogenesis. FASN is an essential metabolic and multifunctional enzyme in fatty acid synthesis. Several studies have reported that SNPs g.841G, g.16024A, g.16039T, and g.17924G have a significant impact on marbling scores in Korean cattle and Japanese Black cattle population. These SNPs are located in transcription factor binding sites, the beta-ketoacyl reductase, and thioesterase domains. Our results revealed that the g.17924 A>G SNP is located in the thioesterase domain of the FASN protein, and changes from polar, neutral, and hydrophilic to nonpolar, aliphatic, and hydrophobic, respectively. In in vivo LM tissue of Korean cattle, the g.17924A>G SNP has an effect on increasing fat deposition. Therefore, g.17924A>G SNP could be a causal mutation for increasing fat deposition in Korean cattle LM tissue.

Gender Difference in the Epidemiological Association between Metabolic Syndrome and Olfactory Dysfunction: The Korea National Health and Nutrition Examination Survey.

Metabolic syndrome (MetS) is associated with a higher risk of morbidity and/or mortality for various chronic diseases. The aim of this study was to investigate the relationships of MetS and its components with olfactory dysfunction in a representative Korean population. We analyzed the data from the Korean National Health and Nutrition Examination Survey (2008-2010). A total of 11,609 adults who underwent otolaryngological examination were evaluated. The olfactory function was classified as normosmia or hyposmia by a self-report questionnaire according to the sense problems of smell during the past 3 months. MetS was diagnosed if a participant had at least three of the following: (1) WC ≥90 cm in men and ≥80 cm in women; (2) fasting blood sugar ≥ 100 mg/dL or medication use for elevated glucose; (3) fasting triglyceride ≥ 150 mg/dL or cholesterol-lowering medication use; (4) HDL-cholesterol <40 mg/dL in men and <50 mg/dL in women or cholesterol-lowering medication use; and (5) SBP ≥ 130 mmHg and/or DBP ≥ 85 mmHg or antihypertensive drug use for patients with a history of hypertension. The prevalence of olfactory dysfunction in the study population was 6.3%. The prevalence of olfactory dysfunction was significantly higher in older people with MetS than in those without MetS in both sexes (male, 42.0 ± 3.4% vs. 34.7 ± 0.9%, p = 0.0354; female, 46.2 ± 2.8% vs. 37.8 ± 0.8%, p = 0.0026). However, elevated waist circumference, elevated fasting glucose, elevated triglycerides, reduced HDL cholesterol, elevated blood pressure, severe stress, depressed mood, and suicidal ideation were significantly associated with olfactory dysfunction only in women. After controlling for confounders, olfactory dysfunction was significantly associated with MetS (odds ratio, 1.352; 95% confidence interval, 1.005-1.820) only in women. MetS are associated with olfactory dysfunction only in Korean women.

Relationship between olfactory dysfunction and suicidal ideation: The Korea National Health and Nutrition Examination Survey.

BACKGROUND: We investigated the relationship between olfactory dysfunction and depressive symptoms and suicidal ideation in South Korea by using data from the 2010-2011 Korea National Health and Nutrition Examination Surveys (KNHANES). METHODS: Cross-sectional data of 11,972 adults who completed the KNHANES were analyzed. RESULTS: The prevalence of olfactory dysfunction was 5.0% among the population ≥ 19 years of age. Olfactory dysfunction was significantly associated with age, alcohol consumption, waist circumference, job, education level, and rhinitis. Depressed mood for two or more continuous weeks was reported by 19.2% of participants with olfactory dysfunction and 12.8% of participants without olfactory dysfunction (p = 0.0009). Suicidal ideation was reported by 20.5% of participants with olfactory dysfunction and 14.1% of participants without olfactory dysfunction (p < 0.0001). The participants with olfactory dysfunction were at higher risk for depressed mood than were participants without olfactory dysfunction (odds ratio [OR] 1.505 [95% confidence interval [CI], 1.106-2.048]) after adjusting for confounders. The participants with olfactory dysfunction were also at higher risk for suicidal ideation (OR 1.306 [95% CI, 1.027-1.662]). CONCLUSION: In the Korean population, olfactory dysfunction was associated with an increased risk for depressed mood and suicidal ideation. Further epidemiologic and experimental studies are necessary to clarify the impact of olfactory dysfunction on psychological diseases.

Human turbinate mesenchymal stromal cell sheets with bellows graft for rapid tracheal epithelial regeneration.

Rapid functional epithelial regeneration on the luminal surface is essential when using artificial tracheal grafts to repair tracheal defects. In this study, we imposed human turbinate mesenchymal stromal cell (hTMSC) sheets for tracheal epithelial regeneration, and then assessed their potential as a new clinical cell source. In vitro, hTMSCs sheets showed high capacity to differentiate into tracheal epithelium. We fabricated a poly(ε-caprolactone) (PCL) tracheal graft by indirect three-dimensional (3D) printing technique and created a composite construct by transplanting the hTMSC sheets to its luminal surface of the tracheal graft, then applied this tissue-engineered tracheal graft to non-circumferential tracheal reconstruction in a rabbit model. 4 weeks after implantation, the luminal surface of tissue-engineered tracheal graft was covered by a mature and highly-ciliated epithelium, whereas tracheal grafts without hTMSC sheets were covered by only a thin, immature epithelium. Therefore, hTMSC sheets on the luminal surface of a tissue-engineered tracheal graft can accelerate the tracheal epithelial regeneration, and the tissue-engineered tracheal graft with hTMSC sheets provides a useful clinical alternative for tracheal epithelial regeneration.

Changes in salivary cortisol levels in pediatric patients with obstructive sleep apnea syndrome after adenotonsillectomy.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) activates the stress response system, including the hypothalamic-pituitary-adrenocortical (HPA) axis. The salivary cortisol, as an index of free circulating cortisol levels, may be used as a measure of HPA axis activity. We examined the change in the salivary cortisol level in pediatric OSAS patients before and after adenotonsillectomy (AT). METHODS: Forty-eight subjects from 80 subjects suspicious of having OSAS were diagnosed with OSAS by overnight PSG, 34 of 48 OSAS patients undergoing AT, and 13 of 34 OSAS patients were finally enrolled prospectively for this study. Before and three months after the AT, the saliva was collected at night before PSG (n-sCor) and in the early morning after PSG (m-sCor) for the measurements of the salivary cortisol level. RESULTS: Children in the study population (n=13) were divided into mild (1< or = AHI <5, n=5), moderate (5 < or = AHI <10, n=3), and severe (AHI > or =10, n=5) OSAS groups. The mean preoperative AHI in the children was 14.7, and the mean postoperative AHI was 0.33. The percentage of children with AHI <1 after AT was 92.3%. Postoperative m-sCor, the difference of cortisol level (sub-sCor: m-sCor minus n-sCor), and the ratio of cortisol level (r-sCor: m-sCor/n-sCor) showed significant difference postoperatively. CONCLUSIONS: AT was associated with improvements in PSG and subjective symptoms in pediatric OSAS patients. In addition, these improvements were significantly related to normalization of salivary cortisol level after AT. Although further study on salivary cortisol levels needs to be done, the measurement of salivary cortisol level before and after AT may predict the outcome of AT as a treatment of OSAS.

Correlation of salivary alpha amylase level and adenotonsillar hypertrophy with sleep disordered breathing in pediatric subjects.

STUDY OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) and sleep disordered breathing (SDB) can affect the sympathetic adrenomedullary system (SAM). As a biomarker of SAM activity, salivary α-amylase (sAA) in pediatric subjects was evaluated whether it has any correlation with polysomnographic (PSG) parameters related to SDB. METHODS: Sixty-seven children who attended our clinic during 1 year were enrolled prospectively and underwent clinical examinations and in-lab polysomnography. The sAA was measured at 2 points--at night before PSG and in the early morning after PSG. RESULTS: Subjects were divided into control (n = 26, apneahypopnea index [AHI] < 1) and OSAS (n = 41, AHI ≥ 1) groups. The OSAS group was subdivided according to AHI (mild-moderate, 1 ≤ AHI < 10; severe, AHI ≥ 10). The sAA subtraction and ratio (p = 0.014 and p < 0.001, respectively) were significantly higher in severe OSAS than in the mild-moderate and control groups. Although oxygen desaturation index (ODI) and AHI were significantly associated with sAA, sAA in the OSAS group was not related to lowest oxygen saturation or adenotonsillar hypertrophy. CONCLUSION: sAA was well related to polysomnographic (PSG) parameters related to SDB, such as AHI and ODI. Therefore, screening test for sAA in children suspected to have SBD may help to identify OSAS patients from control.

Age-related changes of the larynx and trachea assessed by three-dimensional computed tomography in children: Application to endotracheal intubation and bronchoscopy.

The purpose of this study was to establish normative data of laryngotracheal dimensions and shape and to evaluate differences associated with age and sex using three-dimensional (3D) imaging. A total of 120 patients (64 boys and 56 girls) were included. Subjects were divided into four groups: Group 1 (0-2 years), Group 2 (3-7 years), Group 3 (8-13 years), and Group 4 (14-20 years). Using 3D image processing software, the laryngeal volume (LV), tracheal volume (TV), anteroposterior diameter at the glottis, cross-sectional area (CSA) at the subglottis, and laryngeal angle (LA) of the thyroid laminae were measured. Parameters of laryngotracheal volume and size were positively correlated with age, whereas the LA was inversely correlated with age. The LV, TV, CSA-3 mm, and CSA-5 mm exhibited a growth spurt in Groups 2 and 3. The LA decreased at a faster rate in Group 1 (P = 0.012). In Groups 1 and 2, there were no differences between genders for each laryngotracheal segmentation or plane. However, gender differences in the TV of Group 3 were statistically significant (P = 0.030). In Group 4, gender differences of all airway parameters were evident. Volume and other dimensions of the laryngotracheal airway increase with age. There was a significant increase in the LV, TV, CSA-3 mm, and CSA-5 mm in Groups 2 and 3. The LA correlated negatively with age in the Group 1. Significant sex dimorphisms are evident in Group 4.

Relationships between Tumor Volume and Lymphatic Metastasis and Prognosis in Early Oral Tongue Cancer.

OBJECTIVES: Although T stage is an important prognostic tool for oral tongue cancer, it fails to define the depth of invasion and true three-dimensional volume of primary tumors. The purpose of this paper is to determine the relations between tumor volume and lymph node metastasis and survival in early oral tongue cancer. METHODS: Forty-seven patients with T1-2 tongue cancer were included. Tumor volumes were measured by the computerized segmentation of T2-weighted magnetic resonance imaging. RESULTS: The overall average tumor volume was 27.7 cm(3) (range, 1.4 to 60.1 cm(3)). A significant positive correlation was found between tumor volume and pathological T stage, depth of invasion, and cervical lymph node metastasis (P<0.001, P<0.001, and P=0.002, respectively). When the tumor volume exceeded 20 cm(3), the cervical metastasis rate increased to 69.2%. The overall 5-year disease specific survival rate was 80%. There was a statistically significant association between large tumor volume (≥20 cm(3)) and the 5-year disease-specific survival (P=0.046). CONCLUSION: Tumor volume larger than 20 cm(3) was associated with greater risk cervical lymph node metastasis and poor 5-year disease-specific survival rate in early oral tongue cancer patients.

Correlation of salivary cortisol level with obstructive sleep apnea syndrome in pediatric subjects.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is associated with stress system activation involving the hypothalamic-pituitary-adrenocortical (HPA) axis. The relationships among salivary cortisol, a measure of the HPA axis, and objective parameters of polysomnography (PSG) and subjective sleep symptoms were examined. METHODS: Our prospective study enrolled 80 children who had a physical examination, underwent overnight PSG, and completed the Korean version of the modified pediatric Epworth sleepiness scale (KMPESS) and OSA-18 (KOSA-18) questionnaires. Saliva was collected at night before PSG and in the early morning after PSG. RESULTS: Subjects (N=80) were divided into control (n=32, apnea-hypopnea index [AHI]<1) and OSAS (n=48, AHI > or =1) groups; the OSAS group was subdivided into mild (1< or = AHI < 5) and moderate to severe (AHI > or =5) groups. Although salivary cortisol before PSG (n-sCor) did not show a significant change with OSAS severity, salivary cortisol after PSG (m-sCor) significantly decreased with OSAS severity. This decrease resulted in a salivary cortisol ratio (r-sCor) that was significantly different between the control group and the two OSAS subgroups. The m-sCor and sub-sCor of the total group as well as the m-sCor, sub-sCor, and r-sCor of the OSAS group were negatively related to the oxygen desaturation index (ODI). The m-sCor and r-sCor in the OSAS group also were related to subjective sleep symptoms (quality of life [QOL] by KOSA-18). CONCLUSIONS: Among the four salivary cortisol parameters, r-sCor was negatively associated with OSAS severity, ODI, and QOL (KOSA-18), which may indicate a chronically stressed HPA axis. These results demonstrate that salivary cortisol may be a useful biomarker of OSAS.

Usefulness of adenotonsillar size for prediction of severity of obstructive sleep apnea and flow limitation.

OBJECTIVE: Adenotonsillar hypertrophy is considered the most common cause of pediatric obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the relationships between tonsil/adenoid size, parameters of polysomnography, and subjective sleep symptoms. STUDY DESIGN: Case-control studies. SETTING: Tertiary care center. SUBJECTS AND METHODS: A 4-point tonsil grading method and adenoid-nasopharynx (AN) ratio were used to categorize tonsil and adenoid size, respectively. Sleep questionnaires (Korean version of the Obstructive Sleep Apnea-18 [KOSA-18]) and full-attended polysomnography were performed. RESULTS: The subjects (n = 70) were divided into a control group (n = 31, apnea-hypopnea index [AHI] <1) and an OSAS group (n = 39, AHI ≥ 1), which was subdivided into mild and moderate to severe groups. Tonsil/adenoid size showed a statistically significant difference between control and OSAS groups, but these differences had no clinical significance. In addition, tonsil/adenoid size did not differ significantly among 2 OSAS severity subgroups. Only adenoid size in the total and OSAS groups was related to quality of life (QOL) by the KOSA-18. The AN ratio was related to lowest oxygen saturation only in the OSAS group, especially in the moderate to severe OSAS group, but tonsil size was related to flow limitation in total and supine positions in the control group. In the control group, flow limitation was not associated with QOL. CONCLUSION: Tonsil/adenoid size did not predict the severity of AHI. Nevertheless, adenoid size might be related to lowest oxygen saturation, which is thought to be related to subjective symptoms. Although flow limitation was related to tonsil size but not to QOL in the control group, further research will be needed to understand the importance of flow limitation and upper airway resistance syndrome in the pediatric population.

Histiocytic necrotizing lymphadenitis in children: a clinical and immunohistochemical comparative study with adult patients.

OBJECTIVES: Limited information is available regarding the characteristics of histiocytic necrotizing lymphadenitis (HNL) in children. This study compares the clinical and laboratory features as well as the immunohistochemical findings of HNL in children with those of adults. STUDY DESIGN: Retrospective analysis. METHODS: Thirty patients who underwent a biopsy of a cervical lymph node and were histologically proven to have HNL were enrolled in this study. There were 13 children and 17 adults. CD68, CD163 and myeloperoxidase expression were analyzed by immunohistochemical staining. RESULTS: Children had more bilateral lymphadenopathy (P=0.045) and a higher expression of CD68 (P=0.043) than did the adult patients. However, there was no significant difference between the groups in the following variables: patient gender, presence of fever, size and necrosis of enlarged lymph node, multiplicity of lymphadenopathy, WBC count, ESR, CRP, recurrence, and expression of myeloperoxidase and CD163. CONCLUSIONS: The clinical and immunohistological characteristics of HNL in pediatric patients are similar to those of adults. Bilateral involvement of lymph nodes and a high expression of CD68 were the only features significantly associated with children with HNL.

Functional outcome after partial glossectomy with reconstruction using radial forearm free flap.

OBJECTIVE: The purpose of this study was to investigate the relationship between the radial forearm free flap (RFFF) volume changes and speech and swallowing outcomes. METHODS: The study included 18 subjects with squamous cell carcinoma of the oral tongue. RESULTS: Average percentage changes in flap volume between 3 and 12 months was 19.2%. Postoperative free flap volume changes were significantly and negatively correlated with the word and sentence intelligibility (Y=-0.338X+43.641, r(2)=0.383, p=0.006 and Y=-0.246X+34.322, r(2)=0.321, p=0.014, respectively). A significant positive correlation was also found between word and sentence intelligibility and floor of mouth resected, postoperative irradiation. Postoperative flap volume changes between 3 and 12 months were correlated with reduced posterior bolus movement by tongue (p=0.002), reduced tongue base to posterior pharyngeal wall contact (p=0.002), reduced laryngeal elevation (p=0.005), increased aspiration (p=0.005), delayed oral (p=0.010) and pharyngeal transit time (p=0.011). Floor of mouth resected, tongue base resected, and postoperative irradiation also influenced the swallowing outcomes. CONCLUSIONS: This study shows that postoperative flap volume changes are significantly related to speech and swallowing outcomes in patients undergoing partial glossectomy reconstructed with RFFF.

Treatment assessment based on computerized lymph node volume and ratio of necrotic area in tuberculous cervical lymphadenitis.

OBJECTIVE: The objective of this study was to investigate the feasibility of computerized segmentation of lymph nodes to evaluate the relationship of treatment outcomes in tuberculous cervical lymphadenitis (TCL). METHODS: The study included 52 subjects with TCL that had CT before standard medical treatment. The relationship between the medication treatment response, volume and ratio of necrotic area of the largest lymph node in patients with TCL was evaluated. The treatment outcome was defined as the 'responder' (n=35) and 'non-responder' (n=17) groups. Seventeen non-responder patients required surgery. RESULTS: The average lymph node volumes and ratio of necrotic area were 58.59cm(3) (range, 4.96-249.48cm(3)) and 0.30 (range, 0-0.59), respectively. There was a significant difference in the lymph node volumes (34.91±24.00cm(3) vs. 107.04±69.12cm(3), p<0.001) and ratio of necrotic area (0.26±0.12 vs. 0.40±0.14, p=0.001) between responders and non-responders. The receiver-operating-characteristic (ROC) curve analysis was used for differentiating responders from non-responders; it showed that the area under the curve for the lymph node volumes and ratio of necrotic area was 0.845 and 0.759, respectively. The cut-off value for the lymph node volumes and ratio of necrotic area was 44.15cm(3) and 0.36 based on the ROC curve. CONCLUSIONS: A large lymph node volume and high ratio of necrotic area on the 3D reconstruction of CT images were associated with the response to medical treatment for TB. These findings might be useful for assessing treatment outcomes.

Assessment of volume changes of radial forearm free flaps in head and neck cancer: long-term results.

The goal of this study was to evaluate changes in radial forearm free flap (RFFF) volumes after 5 years of follow-up after ablative tumor surgery in the head and neck. Eighteen patients underwent RFFF reconstruction. Flap volumes were measured by computerized segmentation of CT or MR images. Average postoperative 3 months, and 1, 3, and 5 years flap volumes were 167.4, 129.0, 104.9, and 88.7 cm³, respectively. Average percentage changes between 3 months and 1-year, 3 months and 3-years, and 3 months and 5-years scans were 20.4, 30.3, and 42.7%, respectively. A significant relation was found between postoperative irradiation and RFFF volume changes from 3 months to 5 years (p=0.046). Overcorrection with a 40% greater RFFF volume is recommended for the reconstruction of tumor-related defects in the head and neck.