DRG2 is required for surface localization of PD-L1 and the efficacy of anti-PD-1 therapy.

More than half of tumor patients with high PD-L1 expression do not respond to anti-PD-1/PD-L1 therapy, and the underlying mechanisms are yet to be clarified. Here we show that developmentally regulated GTP-binding protein 2 (DRG2) is required for response of PD-L1-expressing tumors to anti-PD-1 therapy. DRG2 depletion enhanced IFN-γ signaling and increased the PD-L1 level in melanoma cells. However, it inhibited recycling of endosomal PD-L1 and reduced surface PD-L1 levels, which led to defects in interaction with PD-1. Anti-PD-1 did not expand effector-like T cells within DRG2-depleted tumors and failed to improve the survival of DRG2-depleted tumor-bearing mice. Cohort analysis revealed that patients bearing melanoma with low DRG2 protein levels were resistant to anti-PD-1 therapy. These findings identify DRG2 as a key regulator of recycling of endosomal PD-L1 and response to anti-PD-1 therapy and provide insights into how to increase the correlation between PD-L1 expression and response to anti-PD-1 therapy.

Extrinsic Laryngeal Muscle Activity With Different Diameters and Water Depths in a Semi-Occluded Vocal Tract Exercise.

PURPOSE: Surface electromyography (sEMG) has been used to evaluate extrinsic laryngeal muscle activity during swallowing and phonation. In the current study, sEMG amplitudes were measured from the infrahyoid and suprahyoid muscles during phonation through a tube submerged in water. METHOD: The sEMG amplitude values measured from the extrinsic laryngeal muscles and the electroglottographic contact quotient (CQ) were obtained simultaneously from 62 healthy participants (31 men, 31 women) during phonation through a tube at six different depths (2, 4, 7, 10, 15, and 20 cm) while using two tubes with different diameters (1 and 0.5 cm). RESULTS: With increasing depth, the sEMG amplitude for the suprahyoid muscles increased in men and women. However, sEMG amplitudes for the infrahyoid muscles increased significantly only in men. Tube diameter had a significant effect on the suprahyoid sEMG amplitudes only for men, with higher sEMG amplitudes when phonating with a 1.0-cm tube. CQ values increased with submerged depth for both men and women. Tube diameter affected results such than CQ values were higher for men when using the wider tube and for women with the narrower tube. CONCLUSIONS: Vocal fold vibratory patterns changed with the depth of tube submersion in water for both men and women, but the patterns of muscle activation differed between the sexes. This suggests that men and women use different strategies when confronted with increased intraoral pressure during semi-occluded vocal tract exercises. In this study, sEMG provided insight into the mechanism for differences between vocally normal individuals and could help detect compensatory muscle activation during tube phonation in water for people with voice disorders.

Clinical Practice Guidelines for Oropharyngeal Dysphagia.

OBJECTIVE: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one's physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. METHODS: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. RESULTS: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. CONCLUSION: This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

FOXO1 Is a Key Mediator of Glucocorticoid-Induced Expression of Tristetraprolin in MDA-MB-231 Breast Cancer Cells.

The mRNA destabilizing factor tristetraprolin (TTP) functions as a tumor suppressor by down-regulating cancer-associated genes. TTP expression is significantly reduced in various cancers, which contributes to cancer processes. Enforced expression of TTP impairs tumorigenesis and abolishes maintenance of the malignant state, emphasizing the need to identify a TTP inducer in cancer cells. To search for novel candidate agents for inducing TTP in cancer cells, we screened a library containing 1019 natural compounds using MCF-7 breast cancer cells transfected with a reporter vector containing the TTP promoter upstream of the luciferase gene. We identified one molecule, of which the enantiomers are betamethasone 21-phosphate (BTM-21-P) and dexamethasone 21-phosphate (BTM-21-P), as a potent inducer of TTP in cancer cells. We confirmed that BTM-21-P, DXM-21-P, and dexamethasone (DXM) induced the expression of TTP in MDA-MB-231 cells in a glucocorticoid receptor (GR)-dependent manner. To identify potential pathways linking BTM-21-P and DXM-21-P to TTP induction, we performed an RNA sequencing-based transcriptome analysis of MDA-MB-231 cells at 3 h after treatment with these compounds. A heat map analysis of FPKM expression showed a similar expression pattern between cells treated with the two compounds. The KEGG pathway analysis results revealed that the upregulated DEGs were strongly associated with several pathways, including the Hippo signaling pathway, PI3K-Akt signaling pathway, FOXO signaling pathway, NF-κB signaling pathway, and p53 signaling pathway. Inhibition of the FOXO pathway using a FOXO1 inhibitor blocked the effects of BTM-21-P and DXM-21-P on the induction of TTP in MDA-MB-231 cells. We found that DXM enhanced the binding of FOXO1 to the TTP promoter in a GR-dependent manner. In conclusion, we identified a natural compound of which the enantiomers are DXM-21-P and BTM-21-P as a potent inducer of TTP in breast cancer cells. We also present new insights into the role of FOXO1 in the DXM-21-P- and BTM-21-P-induced expression of TTP in cancer cells.

DRG2 Depletion Promotes Endothelial Cell Senescence and Vascular Endothelial Dysfunction.

Endothelial cell senescence is involved in endothelial dysfunction and vascular diseases. However, the detailed mechanisms of endothelial senescence are not fully understood. Here, we demonstrated that deficiency of developmentally regulated GTP-binding protein 2 (DRG2) induces senescence and dysfunction of endothelial cells. DRG2 knockout (KO) mice displayed reduced cerebral blood flow in the brain and lung blood vessel density. We also determined, by Matrigel plug assay, aorta ring assay, and in vitro tubule formation of primary lung endothelial cells, that deficiency in DRG2 reduced the angiogenic capability of endothelial cells. Endothelial cells from DRG2 KO mice showed a senescence phenotype with decreased cell growth and enhanced levels of p21 and phosphorylated p53, γH2AX, senescence-associated ß-galactosidase (SA-ß-gal) activity, and senescence-associated secretory phenotype (SASP) cytokines. DRG2 deficiency in endothelial cells upregulated arginase 2 (Arg2) and generation of reactive oxygen species. Induction of SA-ß-gal activity was prevented by the antioxidant N-acetyl cysteine in endothelial cells from DRG2 KO mice. In conclusion, our results suggest that DRG2 is a key regulator of endothelial senescence, and its downregulation is probably involved in vascular dysfunction and diseases.

Clinical Usefulness of the Korean Version of the Dysphagia Handicap Index: Reliability, Validity, and Role as a Screening Test.

This study aimed to measure the validity and reliability of the Korean version of the Dysphagia Handicap Index (K-DHI) and evaluate its diagnostic efficacy for predicting aspiration. We enrolled 104 patients with dysphagia symptoms (D group) and 88 controls (ND group). Among controls, there were 43 patients without dysphagia symptoms (ND patient group). All subjects completed the K-DHI survey. The D and ND group patients underwent the Gugging Swallowing Screen (GUSS) and videofluoroscopic swallowing study (VFSS). Two weeks later, the D group completed the second session of the K-DHI survey. The internal consistency of the K-DHI was good to excellent (Cronbach's α: 0.79-0.95). The test-retest reliability of the K-DHI survey was also high (interclass correlation coefficient = 0.88). There were moderate correlations between the K-DHI and GUSS (r = - 0.65, p < 0.001) as well as findings of VFSS-videofluoroscopic dysphagia scale (r = 0.55, p < 0.001) and American Speech-Language-Hearing Association National Outcome Measurement System swallowing scale (r = - 0.55, p < 0.001). For predicting aspiration, the K-DHI cutoff value was 11 (sensitivity, 0.82; specificity, 0.72; positive predictive value, 0.34; and negative predictive value, 0.96). K-DHI ≥ 11 [odds ratio (OR), 6.43; 95% Confidence Interval (CI) (1.87-22.16); p = 0.003] and GUSS ≤ 15 [OR 4.73; 95% CI (1.59-14.07); p = 0.005] were independent risk factors for aspiration on VFSS. The K-DHI is a reliable and valid self-reporting instrument for evaluating patient's quality of life associated with dysphagia among the Korean language population. It is also useful for the screening of aspiration.

Can a natural singing voice be enhanced through digital processing? Implications of voice training and vocology in singers / ¿Se puede mejorar una voz de canto natural a través del procesamiento digital? Implicaciones del entrenamiento de la voz y la vocología en cantantes

Introduction. The traditional way of facilitating a good singing voice has been achieved through rigorous voice training. In the modern days, however, there are some aspects of the singing voice that can be enhanced through digital processing. Although in the past, the frequency or intensity manipulations had to be achieved through the various singing techniques of the singer, technology today allows the singing voice to be enhanced from the instruments within recording studios. In es-sence, the traditional voice pedagogy and the evolution of digital audio processing both strive to achieve a better quality of the singing voice, but with different methods. Nevertheless, the major aspects of how the singing voice can be manipulated are not communicated among the professionals in each field.Objective. This paper offers insights as to how the quality of the singing voice can be changed physiologically through the traditional ways of voice training, and also digitally through various instruments that are now available in recording studios.Reflection. The ways in which singers train their voice must be mediated with the audio technology that is available today. Although there are aspects in which the digi-tal technology can aid the singer's voice, there remain areas in which the singers must train their singing system in a physiological level to produce a better singing voice

Introducción. La forma tradicional de facilitar una buena voz para cantar se ha lo-grado mediante un riguroso entrenamiento de la voz. Sin embargo, en la actualidad, existen aspectos de la voz cantada que pueden mejorarse mediante el procesamiento digital. Aunque en el pasado las manipulaciones de frecuencia o intensidad tenían que lograrse a través de las diversas técnicas de canto del cantante, la tecnología actual permite ahora mejorar la voz del canto desde los instrumentos dentro de los estudios de grabación. En esencia, la pedagogía de la voz tradicional y la evolución del procesamiento de audio digital se esfuerzan por lograr una mejor calidad de la voz cantada, pero con métodos diferentes. No obstante, los principales aspectos de cómo se puede manipular la voz cantada no se comunican entre los profesionales de cada campo respectivo. Objetivo. Este artículo ofrece información sobre cómo la calidad de la voz cantada se puede cambiar fisiológicamente a través de las formas tradicionales del entrena-miento de la voz, y también digitalmente a través de varios instrumentos que ahora están disponibles en los estudios de grabación. Reflexión. Las formas en que los cantantes entrenan su voz deben estar mediadas por la tecnología de audio que está disponible en la actualidad. Aunque hay aspectos en los que la tecnología digital puede ayudar a la voz del cantante, quedan áreas en las que los cantantes deben entrenar su sistema de canto a nivel fisiológico para pro-ducir una mejor voz al cantar.

Tristetraprolin posttranscriptionally downregulates PFKFB3 in cancer cells.

The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases 3 (PFKFB3) catalyzes the first committed rate-limiting step of glycolysis and is upregulated in cancer cells. The mechanism of PFKFB3 expression upregulation in cancer cells has not been fully elucidated. The PFKFB3 3'-UTR is reported to contain AU-rich elements (AREs) that are important for regulating PFKFB3 mRNA stability. However, the mechanisms by which PFKFB3 mRNA stability is determined by its 3'-UTR are not well known. We demonstrated that tristetraprolin (TTP), an ARE-binding protein, has a critical function regulating PFKFB3 mRNA stability. Our results showed that PFKFB3 mRNA contains three AREs in the 3'-UTR. TTP bound to the 3rd ARE and enhanced the decay of PFKFB3 mRNA. Overexpression of TTP decreased PFKFB3 expression and ATP levels but increased GSH level in cancer cells. Overexpression of PFKFB3 cDNA without the 3'-UTR rescued ATP level and GSH level in TTP-overexpressing cells. Our results suggested that TTP post-transcriptionally downregulated PFKFB3 expression and that overexpression of TTP may contribute to suppression of glycolysis and energy production of cancer cells in part by downregulating PFKFB3 expression.

Doxorubicin inhibits PD-L1 expression by enhancing TTP-mediated decay of PD-L1 mRNA in cancer cells.

Recent research revealed that doxorubicin (DOX) decreased expression of programmed death-ligand 1 (PD-L1) in cancer cells. However, the detailed mechanisms underlying this effect are not well established. Here, we demonstrate that doxorubicin down-regulates PD-L1 expression through induction of AU-rich element (ARE) binding protein tristetraprolin (TTP) in cancer cells. PD-L1 mRNA contain three AREs within its 3'UTR. Doxorubicin induced expression of TTP, increased TTP binding to the 3rd ARE of the PD-L1 3'UTR, and increased decay of PD-L1 mRNA. Inhibition of TTP abrogates the inhibitory effect of doxorubicin on PD-L1 expression. Our data suggest that TTP plays a key role in doxorubicin-mediated down-regulation of PD-L1 by enhancing degradation of PD-L1 mRNA in cancer cells.

DRG2 supports the growth of primary tumors and metastases of melanoma by enhancing VEGF-A expression.

Malignant metastatic melanoma (MM) is the most lethal of all skin cancers, but detailed mechanisms for regulation of melanoma metastasis are not fully understood. Here, we demonstrated that developmentally regulated GTP-binding protein 2 (DRG2) is required for the growth of primary tumors and for metastasis. DRG2 expression was significantly increased in MM compared with primary melanoma (PM) and dysplastic nevi. A correlation between DRG2 expression and poor disease-specific survival in melanoma patients was also identified. Furthermore, inhibition of DRG2 suppressed the binding of Hypoxia-inducible factor 1α to the VEGF-A promoter region, expression of vascular endothelial growth factor (VEGF)-A, and formation of endothelial cell tubes. In experimental mice, DRG2 depletion inhibited the growth of PM and lung metastases and increased survival. These results identify DRG2 as a critical regulator of VEGF-A expression and of growth of PMs and lung metastases.

Tristetraprolin-mediated hexokinase 2 expression regulation contributes to glycolysis in cancer cells.

Hexokinase 2 (HK2) catalyzes the first step of glycolysis and is up-regulated in cancer cells. The mechanism has not been fully elucidated. Tristetraprolin (TTP) is an AU-rich element (ARE)-binding protein that inhibits the expression of ARE-containing genes by enhancing mRNA degradation. TTP expression is down-regulated in cancer cells. We demonstrated that TTP is critical for down-regulation of HK2 expression in cancer cells. HK2 mRNA contains an ARE within its 3'-UTR. TTP binds to HK2 3'-UTR and enhances degradation of HK2 mRNA. TTP overexpression decreased HK2 expression and suppressed the glycolytic capacity of cancer cells, measured as glucose uptake and production of glucose-6-phosphate, pyruvate, and lactate. TTP overexpression reduced both the extracellular acidification rate (ECAR) and the oxygen consumption rate (OCR) of cancer cells. Ectopic expression of HK2 in cancer cells attenuated the reduction in glycolytic capacity, ECAR, and OCR from TTP. Taken together, these findings suggest that TTP acts as a negative regulator of HK2 expression and glucose metabolism in cancer cells.

Tristetraprolin inhibits mitochondrial function through suppression of α-Synuclein expression in cancer cells.

Mitochondrial dynamics play critical roles in maintaining mitochondrial functions. Here, we report a novel mechanism for regulation of mitochondrial dynamics mediated by tristetraprolin (TTP), an AU-rich element (ARE)-binding protein. Overexpression of TTP resulted in elongated mitochondria, down-regulation of mitochondrial oxidative phosphorylation, reduced membrane potential, cytochrome c release, and increased apoptotic cell death in cancer cells. TTP overexpression inhibited the expression of α-Synuclein (α-Syn). TTP bound to the ARE within the mRNA 3'-untranslated regions (3'-UTRs) of α-Syn and enhanced the decay of α-Syn mRNA. Overexpression of α-Syn without the 3'-UTR restored TTP-induced defects in mitochondrial morphology, mitochondrial oxidative phosphorylation, membrane potential, and apoptotic cell death. Taken together, our data demonstrate that TTP acts as a regulator of mitochondrial dynamics through enhancing degradation of α-Syn mRNA in cancer cells. This finding will increase understanding of the molecular basis of mitochondrial dynamics.

Speech Recognition in Real-Life Background Noise by Young and Middle-Aged Adults with Normal Hearing.

BACKGROUND AND OBJECTIVES: People usually converse in real-life background noise. They experience more difficulty understanding speech in noise than in a quiet environment. The present study investigated how speech recognition in real-life background noise is affected by the type of noise, signal-to-noise ratio (SNR), and age. SUBJECTS AND METHODS: Eighteen young adults and fifteen middle-aged adults with normal hearing participated in the present study. Three types of noise [subway noise, vacuum noise, and multi-talker babble (MTB)] were presented via a loudspeaker at three SNRs of 5 dB, 0 dB, and -5 dB. Speech recognition was analyzed using the word recognition score. RESULTS: 1) Speech recognition in subway noise was the greatest in comparison to vacuum noise and MTB, 2) at the SNR of -5 dB, speech recognition was greater in subway noise than vacuum noise and in vacuum noise than MTB while at the SNRs of 0 and 5 dB, it was greater in subway noise than both vacuum noise and MTB and there was no difference between vacuum noise and MTB, 3) speech recognition decreased as the SNR decreased, and 4) young adults showed better speech recognition performance in all types of noises at all SNRs than middle-aged adults. CONCLUSIONS: Speech recognition in real-life background noise was affected by the type of noise, SNR, and age. The results suggest that the frequency distribution, amplitude fluctuation, informational masking, and cognition may be important underlying factors determining speech recognition performance in noise.

Noise-Induced Neural Degeneration and Therapeutic Effect of Antioxidant Drugs.

The primary site of lesion induced by noise exposure is the hair cells in the organ of Corti and the primary neural degeneration occurs in synaptic terminals of cochlear nerve fibers and spiral ganglion cells. The cellular basis of noise-induced hearing loss is oxidative stress, which refers to a severe disruption in the balance between the production of free radicals and antioxidant defense system in the cochlea by excessive production of free radicals induced by noise exposure. Oxidative stress has been identified by a variety of biomarkers to label free radical activity which include four-hydroxy-2-nonenal, nitrotyrosine, and malondialdehyde, and inducible nitric oxide synthase, cytochrome-C, and cascade-3, 8, 9. Furthermore, oxidative stress is contributing to the necrotic and apoptotic cell deaths in the cochlea. To counteract the known mechanisms of pathogenesis and oxidative stress induced by noise exposure, a variety of antioxidant drugs including oxygen-based antioxidants such as N-acetyl-L-cystein and acetyl-L-carnitine and nitrone-based antioxidants such as phenyl-N-tert-butylnitrone (PBN), disufenton sodium, 4-hydroxy PBN, and 2, 4-disulfonyl PBN have been used in our laboratory. These antioxidant drugs were effective in preventing or treating noise-induced hearing loss. In combination with other antioxidants, antioxidant drugs showed a strong synergistic effect. Furthermore, successful use of antioxidant drugs depends on the optimal timing of treatment and the duration of treatment, which are highly related to the time window of free radical formation induced by noise exposure.

Reliability and validity of the Korean version of Pediatric Voice Handicap Index: in school age children.

OBJECTIVE: The aim of this study was to assess the reliability and validity of the Pediatric Voice Handicap Index (pVHI) for cross-cultural adaptation of the Korean version with school age children. METHODS: The questionnaire was translated into Korean and was completed by 101 Korean parents who have children with or without disordered voice. The Korean version-pVHI scores were obtained with 60 parents of normal children and 41 parents who have children with voice problems. Content validity was verified by five experienced speech-language pathologists with clinical specialization in voice disorders. Internal consistency was calculated through Cronbach's α coefficient and test-retest reliability of the Korean version-pVHI score was determined using Pearson product-moment correlation coefficients. Mann-Whitney U test was used to compare GRBAS with the Korean version-pVHI scores between normal and dysphonia group. The relationship between the parent-reported the Korean version-pVHI total scores and perceptual ratings of voice quality from experts was investigated using Spearman correlation coefficients. RESULTS: The results showed that the Korean version-pVHI provided a high internal consistency (α=0.92) and test-retest reliability of its subscales: total (T) 0.97, functional (F) 0.90, physical (P) 0.95, emotional (E) 0.92. The Korean version-pVHI mean scores in normal group were 1.28 (T), 0.62 (F), 0.35 (P) and 0.32 (E), respectively whereas those of the Korean version-pVHI in children group with dysphonia were 23.13 (T), 8.90 (F), 9.54 (P) and 4.93 (E). Significant differences in the Korean version-pVHI (T, F, P, E) and perceptual evaluation (grade, rough, breathy) between normal and dysphonia group were revealed (P<0.05). Moreover, relatively moderate-to-high correlation between the Korean version-pVHI parameters (T) and perceptual measures (G) was exhibited in children with dysphonia. CONCLUSIONS: The subjective Korean version-pVHI can be applicable and useful supplementary tool for evaluating parents' perception of their children's voice dysfunction, identifying multifactors on daily life affecting their children's voice and measuring treatment efficacy before and after therapeutic intervention.

Effect of vocal fold injury location on vibratory parameters in excised canine larynges.

OBJECTIVE: To investigate the effect of vocal fold injury location on vibratory amplitude and lateral phase difference. STUDY DESIGN: Repeated measures with each excised canine larynx serving as own control. SETTING: Basic science study conducted in university laboratory. METHODS: Vocal fold vibration of excised canine larynges was recorded with a high-speed camera before and after inducing vocal fold injury at 1 of 5 locations: anterior, middle, posterior, medial, or superior. Medial and superior injuries were created within the middle third of the vocal fold. Five larynges were used for each of the 5 injury locations. Kymography was performed at the midpoint of the vocal folds for each video. Pre- and postinjury vibratory amplitude and lateral phase difference were compared for each location. RESULTS: The anterior and medial injuries produced consistent decreases in vibratory amplitude. Middle and posterior injuries might slightly decrease amplitude. Superior injuries seemed to have no effect on amplitude. Anterior and medial injuries induced phase asymmetry between the right and left vocal folds. Middle injuries appeared to affect phase difference slightly, whereas posterior and superior injuries had no effect. CONCLUSION: Injury to the anterior or medial portions of the vocal fold may be most likely to cause abnormal vocal fold vibration. Using caution in these locations during phonosurgery may favor superior postoperative vocal outcomes.

Opuntia humifusa supplementation increased bone density by regulating parathyroid hormone and osteocalcin in male growing rats.

We investigated the effect of Opuntia humifusa (O. humifusa) supplementation on bone density and related hormone secretion in growing male rats. Sixteen six-week-old male Sprague-Dawley rats were randomly divided into two groups; control diet group (CG, n = 8), and experimental diet group (EG, n = 8). The rats in the CG were given a control diet and those in the EG were given 5% O. humifusa added to the control diet for eight weeks. The serum OC level of the EG was significantly higher than that of the CG, and the serum parathyroid hormone (PTH) level of EG was significantly lower than that of the CG. In addition, the femoral and tibial BMD of the EG were significantly higher values than those of the CG, and the tibial BMC of the EG was significantly higher than that of the CG. These results suggest that O. humifusa supplementation has a positive effect on bone density by suppressing PTH and increasing the OC level in growing male rats.

Nonlinear dynamic-based analysis of severe dysphonia in patients with vocal fold scar and sulcus vocalis.

OBJECTIVE: The primary goal of this study was to evaluate a nonlinear dynamic approach to the acoustic analysis of dysphonia associated with vocal fold scar and sulcus vocalis. STUDY DESIGN: Case-control study. METHODS: Acoustic voice samples from scar/sulcus patients and age-/sex-matched controls were analyzed using correlation dimension (D2) and phase plots, time-domain based perturbation indices (jitter, shimmer, signal-to-noise ratio [SNR]), and an auditory-perceptual rating scheme. Signal typing was performed to identify samples with bifurcations and aperiodicity. RESULTS: Type 2 and 3 acoustic signals were highly represented in the scar/sulcus patient group. When data were analyzed irrespective of signal type, all perceptual and acoustic indices successfully distinguished scar/sulcus patients from controls. Removal of type 2 and 3 signals eliminated the previously identified differences between experimental groups for all acoustic indices except D2. The strongest perceptual-acoustic correlation in our data set was observed for SNR and the weakest correlation was observed for D2. CONCLUSIONS: These findings suggest that D2 is inferior to time-domain based perturbation measures for the analysis of dysphonia associated with scar/sulcus; however, time-domain based algorithms are inherently susceptible to inflation under highly aperiodic (ie, type 2 and 3) signal conditions. Auditory-perceptual analysis, unhindered by signal aperiodicity, is therefore a robust strategy for distinguishing scar/sulcus patient voices from normal voices. Future acoustic analysis research in this area should consider alternative (e.g., frequency- and quefrency-domain based) measures alongside additional nonlinear approaches.

The effect of segment selection on acoustic analysis.

OBJECTIVE/HYPOTHESIS: Acoustic analysis is a commonly used method for quantitatively measuring vocal fold function. Voice signals are analyzed by selecting a waveform segment and using various algorithms to arrive at parameters such as jitter, shimmer, and signal-to-noise ratio (SNR). Accurate and reliable methods for selecting a representative vowel segment have not been established. STUDY DESIGN: Prospective repeated-measure experiment. METHODS: We applied a moving window method by isolating consecutive, overlapping segments of the raw voice signal from onset through offset. Ten normal voice signals were analyzed using acoustic measures calculated from the moving window. The location and value of minimum perturbation/maximum SNR was compared across individuals. The moving window method was compared with data from the whole vowel excluding onset and offset, the mid-vowel, and the visually selected steadiest portion of the voice signal. RESULTS: Results showed that the steadiest portion of the waveforms, as defined by minimum perturbation and maximum SNR values, was not consistent across individuals. Perturbation and nonlinear dynamic values differed significantly based on what segment of the waveform was used. Other commonly used segment selection methods resulted in significantly higher perturbation values and significantly lower SNR values than those determined by the moving window method (P<0.001). CONCLUSIONS: The selection of a sample for acoustic analysis can introduce significant inconsistencies into the analysis procedure. The moving window technique may provide more accurate and reliable acoustic measures by objectively identifying the steadiest segment of the voice sample.

Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17ß (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17ß.