Effect of Xenogeneic Substances on the Glycan Profiles and Electrophysiological Properties of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Background and Objectives@#Human induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) hold greatpromise as a cellular source of CM for cardiac function restoration in ischemic heart disease. However, the use of animal-derived xenogeneic substances during the biomanufacturing of hiPSC-CM can induce inadvertent immune responses or chronic inflammation, followed by tumorigenicity. In this study, we aimed to reveal the effects of xenogeneic substances on the functional properties and potential immunogenicity of hiPSC-CM during differentiation, demonstrating the quality and safety of hiPSC-based cell therapy. @*Methods@#and Results: We successfully generated hiPSC-CM in the presence and absence of xenogeneic substances(xeno-containing (XC) and xeno-free (XF) conditions, respectively), and compared their characteristics, including the contractile functions and glycan profiles. Compared to XC-hiPSC-CM, XF-hiPSC-CM showed early onset of myocyte contractile beating and maturation, with a high expression of cardiac lineage-specific genes (ACTC1, TNNT2, and RYR2) by using MEA and RT-qPCR. We quantified N-glycolylneuraminic acid (Neu5Gc), a xenogeneic sialic acid, in hiPSC-CM using an indirect enzyme-linked immunosorbent assay and liquid chromatography-multiple reaction monitoring-mass spectrometry. Neu5Gc was incorporated into the glycans of hiPSC-CM during xeno-containing differentiation, whereas it was barely detected in XF-hiPSC-CM. @*Conclusions@#To the best of our knowledge, this is the first study to show that the electrophysiological function andglycan profiles of hiPSC-CM can be affected by the presence of xenogeneic substances during their differentiation and maturation. To ensure quality control and safety in hiPSC-based cell therapy, xenogeneic substances should be excluded from the biomanufacturing process.

The Outcome of Uvulopalatal Flap in Obstructive Sleep Apnea Syndrome Patients

BACKGROUND AND OBJECTIVES: Uvulopalatal flap (UPF), which is a modification of UPPP, is established in the treatment of snoring and obstructive sleep apnea syndrome (OSAS) with reduced velopharyngeal incompetence (VPI) risk. This study was performed to evaluate the subjective outcome of UPF among patients with simple snoring or obstructive sleep apnea. MATERIALS AND METHODS: Twenty patients with OSAS were examined (sixteen male, four female) in a prospective manner. Subjects who underwent UPF have completed pre or post operative (after 3 months) polysomnographic (PSG) studies. The parameters of PSG were apnea index (AI), respiratory disturbance index (RDI), mean SaO2, and lowest SaO2. Questionnaires composed of Eworth sleepiness scale (ESS) and snoring symptoms inventory (SSI) were completed by patients and bed partner before and after the UPF. Statistical analysis was performed using the Wilcoxon signed rank test. RESULTS: Subjective questionnaires indicated statistically significant improvements (SSI ; from 60.9 to 37, ESS ; from 11.6 to 7.4). The AI decreased from 18.6 to 9.3, RDI decreased from 29.8 to 16.6 (p<0.05). CONCLUSION: UPF seems to be more effective in mild OSAS than in moderate and severe OSAS. Long term follow up studies with more patients is deemed necessary.

The Vision and Satisfaction According to Postoperative Refractive Error after AMO Array(R) Multifocal Intraocular Lens Insertion

PURPOSE: To evaluate the visual outcome and satisfaction according to postoperative refractive error in patient with cataract surgery using AMO Array(R) multifocal intraocular lens. METHODS: According to postoperative refractive errors, 120 eyes (80 patients) were inserted the AMO Array(R) multifocal intraocular lens and were divided into three groups respectively: 28 eyes were myopic group (-0.50 ~ -1.50D), 74 eyes were emetropic group (-0.50 ~ +0.50D) and 18 eyes were hyperopic group (+0.50 ~ +1.50D). In each group, distant vision, near vision and contrast sensitivity test were measured. Also the patients were questioned on their satisfaction. RESULTS: Three months after the operation, the distance uncorrected visions of the myopic, emmetropic and hyperopic group were 0.42 +/- 0.23, 0.73 +/- 0.22, 0.36 +/- 0.28 and the near uncorrected visions were 0.47 +/- 0.18, 0.65 +/- 0.03, 0.41 +/- 0.14 in each. There were no difference in satisfaction, contrast sensitivity and glare visual acuity between three groups. CONCLUSIONS: In cataract surgery using the AMO Array(R) multifocal intraocular lens, we could get the best uncorrected visual acuity in emmetopic group. There were no difference in satisfaction and vision between myopic and hyperopic group. Thus, at the time of cataract operation, the multifocal intraocular lens power should be set on emmetropia in order to improve the vision and satisfaction.

Acoustic Analysis of MRI Noise and Induced Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Magnetic resonance (MR) imaging has resulted in a tremendous advance in the technology of medical diagnosis. However, even with all positive advances, there are usually some negative aspects, especially noise. It is well known that loud sounds can induce a hearing loss. This study was performed to determine the acoustic characteristics of MRI noise and whether or not the sound exposure resulting from routine MRI examinations is capable of altering the auditory thresholds of patients. MATERIALS AND METHOD: Digital Impulse Sound Level Meter was placed at patient's head level and at a 2m distance. Frequency of MRI noise was recorded by Digital audio tape and analyzed by Computerized Sound Lab (CSL). A total of 53 adults (106 ears) who were scheduled for MR imaging studies were included in the study. Pure-tone air-conductive auditory threshold was determined bilaterally in each patient before and after MRI. RESULTS: The noise levels at head level ranged from 80.8 dB to 86.0 dB, and at a 2 m distance, from 71.9 dB to 75.9 dB. The frequency ranged from 60 Hz to 2500 Hz. Nine of the 106 ears had a hearing loss of at least 10 dB at one frequency. CONCLUSION: The noise generated by the MRI is sufficiently intense to cause some temporary threshold shifts (TTS). TTS may transform to permanent threshold shifts. Therefore, it is important to devise a method to minimize the risk of these shifts, for example, by using earplug.

Long-Term Polysomnographic Findings and Subjective Results in Sleep Apnea Patients Treated with Laser Assisted Uvulopalatoplasty / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Laser-assisted uvulopalatoplasty (LAUP) is well established in the treatment of snoring and obstructive sleep apnea syndrome (OSAS), although most reports are based on short-term follow-up results. This study was performed to determine the long-term effects on symptoms and polysomnographic measures in patients with OSAS after 5yrs of LAUP. MATERIALS AND METHOD: Fifty patients with OSAS underwent LAUP, and of these patients, 20 have completed postoperative polysomnographic studies. Questionnaires ranking snoring and apneic symptoms were completed by the patient and bed partner before LAUP. The parameters of measurement were apnea index (AI), respiratory disturbance index (RDI), SaO2, and sleep stages. The statistical analysis was performed using Wilcoxon signed rank test. RESULTS: Subjective questionnaires showed statistically significant improvements in snoring, falling asleep while day work, headache upon wakening. The symptomatic improvement persisted long time. The AI decreased from 15.9 to 10.5, RDI decreased from 23.2 to 14.9, and the mean, lowest O2 saturation increased from 85, 93 to 92, 97 (p<0.05). The RDI was reduced to 10 or less in 40% of patients. CONCLUSION: LAUP is an effective method for the management of mild OSAS. Authors have demonstrated long-term improvement in subjective and polysomnographic measures.

Change of Voice Quality on Menstrual Cycle / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The change of voice quality on menstrual cycle is regarded as general in professionals. The primary objective of this study is to evaluate the changes of acoustic parameters during menstrual cycle in general population. METHODS: Twenty young adults were asked to produce vowel /a/, /i/ , and /u/ and to read book audibly at the proliferative phase of the menstrual cycle and premenstrual phase. And then, the sound of the voice in each case was recorded and analyzed by the Computerized Speech Lab. (CSL, Kay Elemetrics, Model 4300B, USA). The statistical analyses were performed using paired t-test to compare several variables of data. RESULTS: Compared with the acoustic parameters between two periods, there were no significant differences in all subjects. But the acoustic parameters with book-reading loudly during menstrual cycles revealed slight changes in voice quality. CONCLUSION: The change of voice quality, especially the fatigue of voice may be concerned with menstrual cycle, so more careful voice habituation was required during the menstrual period.

An Acoustic and Radiologic Study on Voice Change after Laser Assisted Uvulopalatoplasty / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Many people have been concerned about voice change after laser assisted uvulopalatoplasty (LAUP). A number of studies reported acoustic changes after uvulopalatopharyngoplasty (UPPP) and LAUP. However, there have not been any reports on the association between anatomic change and acoustic results after LAUP. The purpose of this study is to analyze changes in the voice and changes in the vocal tract after LAUP and to evaluate whether the anatomical changes of vocal tract have an effect on the voice change or not. SUBJECTS AND METHOD: By using CSL, we analyzed fourteen LAUP cases on the formant frequencies of six vowels (/a/, /i/, /u/, /=, /o/, /e/) and four nasal consonants (/hana/, /eomma/, /eoungga/, /chiken/). By using MR image, we analyzed changes in the vocal tract eight weeks after LAUP with preoperative findings in three cases. RESULTS: In acoustic analysis, the second formant frequencies of /u/ and /= phonation were significantly reduced postoperatively compared to those of preoperative status. In imaging study of /u/ and /=, the uvula and soft palate were contracted, so coupling was occurred between nasal cavity and oropharynx in /u/ and /= phonation and the tongue was shifted toward posterior pharyngeal wall to compensate coupling. CONCLUSION: LAUP reduced the second formant of /u/ and /=, which did not result in serious voice changes.

Computed Tomographic Measurements of the External Auditory Canal and the Temporal Bone / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: High-resolution computed tomography provides an excellent method for examination of the middle ear, inner ear anatomy and pathologic changes in the temporal bones. The purpose of this study was to get various measurements of the external auditory canal and temporal bones, and to compare the changes with age and sex. MATERIALS AND METHOD: The various measurements by CT of the external ear canal of normal 50 ears were done. RESULTS: The obtained results were as follows: 1) In both male and female group, the distance from the medial end of EAC to bony-cartilage junction, the distance from medial end of EAC to the lateral end of cartilage, the distance from the superior wall to the inferior wall (coronal EAC isthmus) and the distance from anterior wall to the posterior wall (axial EAC isthmus) increased significantly with age (p<0.05). 2) Compared with the female group, the male group had longer distance from the posterior tympanic plate to the sinus tympani with age (p<0.05). 3) Compared with male group, the female group had longer distance from the posterior EAC wall to the Sigmoid sinus and from the EAC superior wall to the tegmen tympani with age (p<0.05). 4) In both male and female groups, the anterior and inferior angles increased and the posterior and superior angles decreased with age (p<0.05). CONCLUSION: Computed tomographic evaluation can give us to information to operate external ear, middle ear, and inner ear surgery.