Foreign Body Complications in Ears due to Mishandled Hearing Aid Fitting and Proposed Clinical Guidelines to Address the Complications.

BACKGROUND: South Korea has one of the world's fastest aging populations and is witnessing increased age-related hearing impairment cases as well as an increase in the number of hearing aid users. The aim of this study was to analyze complications caused by hearing aid mold materials. In addition, we hope to raise awareness of the harm and danger that inexperienced hearing aid providers can cause to patients. METHODS: We retrospectively reviewed the medical records of 11 patients who were diagnosed with hearing aid mold material as a foreign body in the ear at a tertiary center between 2016 and 2020. The following data were analyzed: symptoms, endoscopic findings, audiometry, temporal bone CT images, treatment methods, and complications after removal. The currently available literature was also reviewed to develop clinical guidelines, to identify the systematic weaknesses in the South Korean hearing aid market, and to identify policies that warrant better quality control. RESULTS: Among the 11 cases, 9 were restricted to the external auditory canal, all of which were successfully removed under endoscopy with minor complications. Two cases with middle ear involvement resulted in infection and thus required surgical removal with mastoidectomy. The average age of these patients was 76.4, and all patients received their molding procedure at private hearing aid shops without an otolaryngologist's examination. CONCLUSION: Thorough patient history-taking and otologic examination must be performed to identify patients at higher risk of complications. Such patients should be referred to an otolaryngologist. If a patient exhibits alarming symptoms, early referral is critical since prompt surgery can minimize complications. A CT scan is highly recommended to determine an optimal approach for foreign body removal. Systematic and regulatory changes in hearing aid dispensers, such as requiring apprenticeship, raising the required level of education, and legally mandating referrals, can help reduce these complications.

WSN-SES/MB: System Entity Structure and Model Base Framework for Large-Scale Wireless Sensor Networks.

Large-scale wireless sensor networks are characterized by stringent energy and computation restrictions. It is exceedingly difficult to change a sensor network's environment configurations, such as the number of sensor nodes, after deployment of the nodes. Although several simulators are able to variously construct simulation models for sensor networks before their deployment, the configurations should be modified with extra human effort as the simulators cannot freely generate diverse models. In this paper, we propose a novel framework, called a system entity structure and model base for large-scale wireless sensor networks (WSN-SES/MB), which is based on discrete event system specification formalism. Our proposed framework synthesizes the structure and models for sensor networks through our modeling construction process. The proposed framework achieves time and cost savings in constructing discrete event simulation-based models. In addition, the framework increases the diversity of simulation models by the process's pruning algorithm. The simulation results validate that the proposed framework provides up to 8% time savings and up to 23% cost savings as compared to the manual extra effort.

Asymmetric Host Molecule Bearing Pyridine Core for Highly Efficient Blue Thermally Activated Delayed Fluorescence OLEDs.

In this study, two host materials, pCzBzbCz and pCzPybCz, are synthesized to achieve a high efficiency and long lifetime of blue thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs). The molecular design strategy involves the introduction of a pyridine group into the core structure of pCzPybCz as an electron-withdrawing unit, and an electron-donating phenyl group into the structure of pCzBzbCz. These host materials demonstrate good thermal stability and high triplet energy (T1 =3.07 eV for pCzBzbCz and 3.06 eV for pCzPybCz) for the fabrication of blue TADF-OLEDs. In particular, pCzPybCz-based OLED devices demonstrate an external quantum efficiency (EQE) of 22.7 % and an operational lifetime of 24 h (LT90 , time to attain 90 % of initial luminance) at an initial luminance of 1000 cd m-2 . This superior lifetime could be explained by the C-N bond dissociation energy (BDE) in the host molecular structure. Furthermore, a mixed-host system using the electron-deficient 2,4-bis(dibenzo[b,d]furan-2-yl)-6-phenyl-1,3,5-triazine (DDBFT) is proposed to inhibit the formation of the anion state of our host materials. In short, the device operational lifetime is further improved by applying DDBFT. The carbazole-based asymmetric host molecule containing a pyridine core realizes a high-efficiency blue TADF-OLED showing a positive effect on the operating lifetime, and can provide useful strategies for designing new host materials.

Prognostic value of soluble ST2 and soluble LR11 on mortality and cardiovascular events in peritoneal dialysis patients.

BACKGROUND: Although the soluble form of suppression of tumorigenicity 2 (sST2) and soluble low-density lipoprotein receptor relative with 11 ligand-binding repeats (sLR11) have emerged as novel cardiovascular biomarkers in patients with cardiovascular disease, their prognostic value has not been fully investigated in peritoneal dialysis (PD) patients. METHODS: We included 74 prevalent PD patients from a prospective cohort and measured serum sST2 and sLR11 concentrations by an enzyme-linked immunosorbent assay. The association of these biomarkers and all-cause mortality and major adverse cardiac and cerebrovascular events (MACCEs) was evaluated. RESULTS: During a follow-up of 38.5 months, all-cause deaths and MACCEs were observed in 13 (17.6%) patients and 23 (31.3%) patients. Multivariable Cox analyses demonstrated that greater sST2 was independently associated with higher risk of all-cause mortality (≥75.8 ng/mL; hazard ratio [HR] = 5.551; 95% confidence interval [CI] = 1.360-22.660) and MACCEs (≥72.5 ng/mL; HR = 4.609; 95% CI = 1.608-13.208). Furthermore, sST2 showed additive predictive value for mortality to the base model including traditional risk factors (net reclassification index = 0.598, P = 0.04). sLR11 was not significantly associated with all-cause mortality or MACCE. CONCLUSIONS: sST2, but not sLR11, indicated a significant prognostic value for all-cause mortality and cardiovascular events in PD patients. Further research is needed to validate emerging biomarkers in these populations.

Herpes zoster does not increase the risk of sudden sensory neural hearing loss: a longitudinal follow-up study using a national sample cohort.

Objective: This study aimed to investigate the risk of sudden sensorineural hearing loss (SSNHL) in Herpes zoster patients from a representative population cohort.Design: A longitudinal follow-up studyStudy sample: Data were obtained from the Korean National Health Insurance Service-National Sample Cohort for the period from 2002 to 2013. We matched 61,702 subjects in the Herpes zoster group with subjects in a control group (246,808 subjects with no history of Herpes zoster) based on demographic factors (age, sex, income, and region of residence) and medical history (diabetes, dyslipidemia, and hypertension). The crude (simple) and adjusted hazard ratios (HRs) for Herpes zoster with SSNHL were analysed using the Cox-proportional hazard model.Results: Only 0.5% (338/61,364) of the Herpes zoster group and 0.7% (1664/245,144) of the control group showed SSNHL. The Herpes zoster group did not exhibit a higher rate of SSNHL (adjusted HR = 0.81, 95% CI = 0.72-0.91, p < 0.001) than the control group. In subgroup analyses, no age subgroups showed a significant risk of SSNHL in the Herpes zoster group.Conclusions: After adjusting for confounding factors, the risk of SSNHL did not increase in the Herpes zoster group compared with the control group.

Frequency of non-single canals in mandibular premolars and correlations with other anatomical variants: an in vivo cone beam computed tomography study.

BACKGROUND: A knowledge regarding anatomical variants is important to achieve success in endodontic treatment. Root canal treatment of mandibular first premolars (PM1 s) is challenging due to the existence of numerous variations in canal configurations, including a C-shaped variant. We aim to determine the frequency and morphologic characteristics of non-single canals of mandibular first (PM1 s) and second (PM2 s) premolars in a Korean population using cone beam computed tomography (CBCT) and to evaluate correlations between non-single canals of PM1 s and other anatomical variants, such as distolingual roots (DLRs) in mandibular first molars (M1 s) and C-shaped canals in mandibular second molars (M2 s). METHODS: A total of 971 PM1 s and 997 PM2 s from 500 patients were examined in vivo by CBCT. Root canal configurations and C-shaped canals were determined in accordance with the Vertucci classification and Fan classification, respectively. The correlation between non-single canals in PM1 s and DLRs in M1 s was evaluated using logistic regression analysis. RESULTS: PM2 s typically had one root (99.89%) with one canal (98.4%). Among PM1 s with non-single canals (21.2%), Vertucci type V (10.9%) and C-shaped (3.7%) canals were prevalent. Among C-shaped PM1 canals, the majority were Vertucci type V (77.8%); a C-shaped configuration (C2) was predominant mostly at the middle and/or apical third of the root. After adjusting for other variables (i.e., sex, age, and side), C-shaped canals in PM1 s was significantly correlated with the presence of DLRs in M1 s (odds ratio = 2.616; 95% confidence interval, 1.257-5.443; p = 0.010). CONCLUSIONS: The presence of C-shaped PM1 canals was positively related to the presence of DLRs in M1 s. Although C-shaped canals in PM1 s are difficult to distinguish, this finding could aid clinicians in predicting C-shaped canal configurations in PM1 s of patients who exhibit DLRs in M1 s.

Prevalence of Dizziness and Associated Factors in South Korea: A Cross-Sectional Survey From 2010 to 2012.

BACKGROUND: Dizziness is one of the most common complaints in medicine and a frequent symptom among older people. Dizziness has a considerable impact on life quality and is associated with high economic costs. The purpose of this study was to evaluate the prevalence of dizziness in the general population and to describe its clinical characteristics and associated factors. METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) is a cross-sectional survey of the civilian, non-institutionalized population of South Korea. We evaluated data for 12,653 participants (5,450 men and 7,203 women), aged 40 years and above, whom participated in the KNHANES between 2010 and 2012. RESULTS: In the age group over 40 years old, the 1-year prevalence of dizziness was 20.10%. Dizziness was more prevalent among women (25.18%) than among men (14.57%; P < 0.001) and the prevalence rate increased with age (P < 0.001). In multivariable analysis, female sex, older age, serum triglyceride level, experience of depression, limited functional status owing to visual acuity impairment, limited physical performance, smoking, alcohol consumption, and perception of stress were independently associated with dizziness. CONCLUSIONS: In our study, the prevalence of dizziness in the general population was 20.10%. There was a stronger relationship between dizziness and physical performance, chronic diseases, and health behaviors compared to that with otologic diseases. Interventions for dizziness should be approached in a multifactorial manner and an understanding of various factors is necessary for the prevention and management of this condition.

Isolated horizontal positional nystagmus from a posterior fossa lesion.

Isolated vertigo with horizontal positional nystagmus as an impending sign of a central lesion has rarely been reported. Here we present neuro-otologic findings of patients with these clinical signs. Lesion overlays from 6 patients with ageotropic positional nystagmus revealed that the nodulus and vermis are common areas of injury. In contrast, 2 patients with geotropic positional nystagmus had cerebellar peduncle and lateral medullary lesions. These clinical findings suggest that vertigo with horizontal positional nystagmus, even in the absence of other initial neurological signs, may indicate a posterior fossa lesion, including that in the nodulus, vermis, and deep cerebellar structures.

Low-fat and low-protein diets are associated with hearing discomfort among the elderly of Korea.

Research on the effect of low-fat intake on hearing is limited. This study aimed to elucidate the relationship between fat, carbohydrate and protein intake and the presence of hearing discomfort among the elderly. The Korean National Health and Nutrition Examination Survey was conducted from 2009 through to 2012. A total of 4615 participants ranging in age from 60 to 80 years underwent a pure-tone audiometric evaluation, a physical examination and a nutritional survey. The associations between the participants' hearing thresholds and their protein/fat/carbohydrate intake/total energy intake were analysed using simple and multiple regression models with complex sampling adjusted for confounding factors, such as BMI, income level, smoking status and a history of hypertension, hyperlipidaemia and diabetes. Low fat and protein intakes were associated with hearing discomfort (OR 0·82, 95 % CI 0·71, 0·96, P=0·011; OR 0·81, 95 % CI 0·67, 0·96, P=0·017, respectively). This study revealed that low fat and protein intakes are associated with hearing discomfort in the elderly Korean population.

Analysis of Predisposing Factors for Hearing Loss in Adults.

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

An analysis of normative data on the knee rotatory profile and the usefulness of the Rotatometer, a new instrument for measuring tibiofemoral rotation: the reliability of the knee Rotatometer.

PURPOSE: This study proposes a simple and noninvasive instrument called the "Rotatometer" to measure tibiofemoral rotation and investigates its clinical applicability to the assessment of static rotational knee laxity. METHODS: The degree of tibiofemoral rotation was measured for a sample of 94 healthy volunteers with 188 knees by using the Rotatometer. The measurement was made by two independent and blinded examiners in three sessions at one-month intervals. The normative rotational profile and its relationship with gender and age were evaluated, and inter-observer reliability and intra-observer reliability were calculated. RESULTS: Males showed 62° ± 5° of external rotation, whereas females, 64° ± 5°. Males showed 44° ± 5° of internal rotation, whereas females, 49° ± 4°. Females showed significantly higher degrees of rotation than males. Tibiofemoral rotation was not correlated with age, and external rotation and internal rotation had a moderate positive relationship. Inter-observer reliability ranged from 0.84 to 0.91 for external rotation and 0.90 to 0.95 for internal rotation, and intra-observer reliability ranged from 0.69 to 0.89 for external rotation and 0.87 to 0.95 for internal rotation. CONCLUSIONS: The results suggest the Rotatometer to be a simple and noninvasive device with high inter- and intra-observer reliability. The device can provide a normative rotational profile for reference purposes and thus can be used to determine the preoperative and postoperative rotational status of knees with anterior cruciate ligament injuries and compare results from different reconstruction techniques.

Clinical observation on acute low-frequency hearing loss without vertigo: the role of cochlear hydrops analysis masking procedure as initial prognostic parameter.

OBJECTIVES: Even though it is currently not possible to prove a pathological diagnosis for inner ear disease, acute low-frequency hearing loss (ALFHL) without vertigo could be caused by inner ear hydrops because progression into the clinical spectrum of endolymphatic hydrops (EH) frequently occur among patients with the initial clinical presentation. Therefore, audiological measures representative of inner ear hydrops, such as the cochlear hydrops analysis masking procedure (CHAMP) test, may be used to predict the prognosis of ALFHL without vertigo. To test this hypothesis, we prospectively investigated patients with ALFHL unaccompanied by vertigo and examined whether the CHAMP test generated more useful information for prediction of progression into clinical spectrum of EH compared with other neurotologic parameters. DESIGN: A prospective clinical study of 28 patients who initially presented with ALFHL without vertigo was conducted. Detailed neurotologic findings from pure-tone audiometry, electrocochleography, CHAMP, spontaneous nystagmus, head-shaking nystagmus, vibration-induced nystagmus, the bithermal caloric test, and the rotatory chair test were recorded at the time of initial presentation. A regular audiological and clinical examination was conducted until either the last follow-up at our clinic or on the day on which secondary audiovestibular symptoms occurred. The rates of progression to Ménière's disease (MD) or clinical presentation compatible with isolated cochlear hydrops during the study period were calculated by the log-rank test and relative risk. A receiver operating characteristics curve was plotted to determine the prognostic value of CHAMP. RESULTS: Of 28 patients, 15 (53%) showed improvement in hearing on pure-tone audiometry. Seven patients (25%) showed hearing fluctuation and nine (32%) developed a vertigo attack during the observation period. Of these, three patients experienced both vertigo and a hearing fluctuation. Abnormal results of electrocochleography and neurotologic tests reflecting vestibular ocular reflex on yaw plane were common at the time of diagnosis of ALFHL in many patients, but these parameters were not associated with an increased risk of progression of clinical spectrum of EH. In contrast, patients with an abnormal complex amplitude ratio (CAR) on CHAMP had a 2.6-fold increased risk of progression to a clinical spectrum of EH (either hearing fluctuation or MD). The hazard ratio of developing MD for patients with normal CAR as compared with those with an abnormal CAR was 0.137 (95% confidence interval 0.03-0.57; p < 0.001), which indicates an 84.3% reduced risk of developing MD in those with normal CAR. A CAR value of 0.975 or less indicated the possibility of developing either a hearing fluctuation or vertiginous episode with a sensitivity of 82% and a specificity of 73% by receiver operating characteristics curve analysis. CONCLUSIONS: The results of the study suggest that CHAMP measurement may be useful for determining the prognosis of patients with ALFHL without vertigo. A CAR value of 0.975 or less indicates the possibility of developing fluctuating hearing loss or vertigo in patients with ALFHL unaccompanied by vertigo.

25-hydroxyvitamin D levels and vascular calcification in predialysis and dialysis patients with chronic kidney disease.

BACKGROUND/AIMS: The role of vitamin D in the process of vascular calcification is unclear in patients with chronic kidney disease. We investigated whether serum 25-hydroxyvitamin D [25(OH)D] is associated with vascular calcification in predialysis and dialysis patients. METHODS: We included 86 predialysis and 139 dialysis patients. The simple vascular calcification score (SVCS) was evaluated by examining plain X-rays of the pelvis and hands as described previously. The carotid-to-femoral pulse wave velocity (CF-PWV) was assessed with a commercially available device. RESULTS: We found a high prevalence of vitamin D deficiency in our population (78.2%). Vascular calcification was present in 46.2% of all patients. Higher calcification (SVCS >3) was significantly associated with lower 25(OH)D levels in predialysis and dialysis patients. Multiple logistic regression analysis for SVCS >3 showed that 25(OH)D levels were negative independent predictors in predialysis (OR: 0.781; 95% CI: 0.623-0.908, p = 0.019) and dialysis patients (OR: 0.805; 95% CI: 0.749-0.853, p = 0.009). Lower 25(OH)D levels were associated with higher CF-PWV in predialysis patients, but this inverse relationship was no longer present in multivariate analysis. CONCLUSION: We showed an independent relationship between low serum 25(OH)D levels and vascular calcification in both predialysis and dialysis patients.

Risk factors affecting seroconversion after influenza A/H1N1 vaccination in hemodialysis patients.

BACKGROUND: Hemodialysis (HD) patients have multiple causes of immune dysfunction and poor immune response to influenza vaccination. We investigated the antibody response rate to a pandemic H1N1/2009 influenza vaccination and clinical parameters influencing the induction of antibody responses in HD patients. METHODS: A total of 114 HD patients were vaccinated with a monovalent adjuvanted H1N1 inactivated influenza vaccine. Titers of neutralizing antibodies were evaluated by hemagglutination inhibition (HI) assay at pre- and 4 weeks after vaccination. Seroconversion was defined as either a pre-vaccination HI titer < 1:10 and a post vaccination HI titer > 1:40 or a pre-vaccination HI titer ≥ 1:10 and a minimum four-fold rise in post-vaccination HI antibody titer. Seventeen out of 114 HD patients (14.9%) tested positive for antibodies against influenza A/H1N1/2009 before vaccination. The remaining 97 baseline sero-negative patients were included in the analysis. RESULTS: Only 30 (30.9%) HD patients had seroconversion 4 weeks after vaccination. The elderly patients, those over 65 years of age, showed significantly lower seroconversion rate compared to younger HD patients (20.5% vs. 39.6%, p = 0.042). Furthermore, patients with hemoglobin values less than 10 g/dL had a significantly lower seroconversion rate compared to those with higher hemoglobin values (20.0 vs. 38.6%, p = 0.049). By multivariate logistic regression analysis, only age ≥65 years (OR = 0.336, 95% confidence interval (CI) 0.116-0.971, p = 0.044) and hemoglobin levels <10 g/dL (OR = 0.315, 95% CI 0.106-0.932, p = 0.037) were independently associated with seroconversion after vaccination. CONCLUSIONS: Our data show that HD patients, especially who are elderly with low hemoglobin levels, are at increased risk for lower seroconversion rate after influenza A/H1N1 vaccination. Further studies are needed to improve the efficacy of vaccination in these high risk patients.

Korean clinical practice guidelines: otitis media in children.

Acute otitis media (AOM) and otitis media with effusion (OME) are common infections in children, and their diagnosis and treatment have significant impacts on the health of children and the costs of providing national medical care. In 2009, the Korean Otologic Society organized a committee composed of experts in the field of otolaryngology, pediatrics, and family medicine to develop Korean clinical practice guidelines (CPG) for otitis media in children with the goal of meeting regional medical and social needs in Korea. For this purpose, the committee adapted existing guidelines. A comprehensive literature review was carried out primarily from 2004 to 2009 using medical search engines including data from Korea. A draft was written after a national questionnaire survey and several public audits, and it was editorially supervised by senior advisors before publication of the final report. These evidence-based guidelines for the management of otitis media in children provide recommendations to primary practitioners for the diagnosis and treatment of children younger than 15 yr old with uncomplicated AOM and OME. The guidelines include recommendations regarding diagnosis, treatment options, prevention and parent education, medical records, referral, and complementary/alternative medicine for treating pediatric otitis media.

Analysis of psychological distress after management of dizziness in old patients: multicenter study.

Dizziness is a common problem in older people, with a reported prevalence of 13-38%. A large percentage of patients with dizziness develop secondary psychiatric disorders over the course of their disease. In particular, clinical depression and anxiety are significant health problems for older adults. We investigated the relationship between dizziness and psychological distress (depression and anxiety) in elderly patients with dizziness, and the relationship with psychological symptoms after managing the dizziness. This study enrolled 126 patients with dizziness, who were 65 years or older. Dizziness and the psychological symptoms of all patients were measured using the Korean Version of the Vestibular Disorders Activities of Daily Living Scale (K-VADL), the Beck Depression Inventory (BDI), and the Spielberger State-Trait Anxiety Inventory (STAI) before and after management. We found a significant decrease in the BDI and STAI state scores after treatment with a reduction in the K-VADL score. For the STAI, the decrease in the score was relatively small after management. Nevertheless, there were significant correlations between the K-VADL score and both the BDI and STAI scores before and after management. Therefore, in the management of elderly patients with dizziness, a psychiatric approach should be considered and psychological support may be needed after managing the dizziness.

Kidney Mesenchymal Stem Cell-derived Extracellular Vesicles Engineered to Express Erythropoietin Improve Renal Anemia in Mice with Chronic Kidney Disease.

Extracellular vesicles (EVs) shed from kidney mesenchymal stem cells (KMSCs) show protective effects against acute kidney injury and progressive kidney fibrosis via mRNA transfer. Previous studies report improvement of renal anemia following administration of genetically modified MSCs or peritoneal mesothelial cells that secrete erythropoietin (EPO). Here, we determined whether EPO-secreting KMSC-derived EVs (EPO(+)-EVs) can improve renal anemia in mouse models of chronic kidney disease (CKD). The mouse CKD and renal anemia model was induced by electrocoagulation of the right renal cortex and sequential left nephrectomy. At six weeks post-nephrectomy, we observed significantly lower hemoglobin (10.4 ± 0.2 vs. 13.2 ± 0.2 g/dL) and significantly higher blood urea nitrogen and serum creatinine levels in CKD mice relative to controls (60.5 ± 0.5 and 0.37 ± 0.09 mg/dL vs. 19.9 ± 0.5 and 0.12 ± 0.02 mg/dL, respectively). Genetically engineered EPO(+)-KMSCs secreted 71 IU/mL EPO/106 cells/24 h in vitro, and EPO(+)-EVs isolated by differential ultracentrifugation expressed EPO mRNA and horizontally transferred EPO mRNA into target cells in vitro and in vivo. Furthermore, at two weeks post-injection of EPO(+)-KMSCs or EPO(+)-EVs into CKD mice with renal anemia, we observed significant increases in hemoglobin levels (11.7 ± 0.2 and 11.5 ± 0.2 vs. 10.1 ± 0.2 g/dL, respectively) and significantly lower serum creatinine levels at eight weeks in comparison to mice receiving vehicle control (0.30 ± 0.00 and 0.23 ± 0.03 vs. 0.43 ± 0.06 mg/dL, respectively). These results demonstrate that intraperitoneal administration of EPO(+)-EVs significantly increased hemoglobin levels and renal function in CKD mice, suggesting the efficacy of these genetically engineered EVs as a promising novel strategy for the treatment of renal anemia.

Neurobiological Signatures of Auditory False Perception and Phantom Perception as a Consequence of Sensory Prediction Errors.

In this study, we hypothesized that top-down sensory prediction error due to peripheral hearing loss might influence sensorimotor integration using the efference copy (EC) signals as functional connections between auditory and motor brain areas. Using neurophysiological methods, we demonstrated that the auditory responses to self-generated sound were not suppressed in a group of patients with tinnitus accompanied by significant hearing impairment and in a schizophrenia group. However, the response was attenuated in a group with tinnitus accompanied by mild hearing impairment, similar to a healthy control group. The bias of attentional networks to self-generated sound was also observed in the subjects with tinnitus with significant hearing impairment compared to those with mild hearing impairment and healthy subjects, but it did not reach the notable disintegration found in those in the schizophrenia group. Even though the present study had significant constraints in that we did not include hearing loss subjects without tinnitus, these results might suggest that auditory deafferentation (hearing loss) may influence sensorimotor integration process using EC signals. However, the impaired sensorimotor integration in subjects with tinnitus with significant hearing impairment may have resulted from aberrant auditory signals due to sensory loss, not fundamental deficits in the reafference system, as the auditory attention network to self-generated sound is relatively well preserved in these subjects.

MTHFR C677T polymorphism as a risk factor for vascular calcification in chronic hemodialysis patients.

Polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T is one of the suggested risk factors for atherosclerosis. However, few studies have reported on the relationship between MTHFR C677T polymorphism and vascular calcification (VC) in chronic hemodialysis patients. We investigated the relationship between the MTHFR C677T polymorphism and VC in 152 chronic hemodialysis patients. Patients with a TT genotype exhibited significantly higher VC scores than patients expressing CC and CT (P = 0.002). The prevalence of peripheral vascular disease increased with the incidence of MTHFR C677T mutations for all patients, and the incidence of cerebrovascular accidents also increased with the presence of mutations for young patients (≤ 60 yr) (P < 0.05). Patients with CT and TT genotypes had adjusted odds ratios for VC of 1.39 and 1.58, respectively (P < 0.05). In summary, these data suggest that the MTHFR C677T polymorphism affects the degree of VC in chronic hemodialysis patients.