Occupational Hearing Loss

Occupational hearing loss received attention after the Industrial Revolution and through World Wars I and II. It currently accounts for the largest portion of occupational diseases, and a third of all hearing loss is due to noise. Occupational hearing losses include noise-induced hearing loss (NIHL), hearing loss caused by ototoxic substances and hearing loss caused by their complex interactions. In the case of NIHL, even when exposed to the same noise, the degree of hearing damage and recovery may vary from person to person, and also be affected by other noise in daily life. Various organic solvents and some heavy metals exposed in workplace are important causes of ototoxic hearing loss, and they are known to have additive or synergistic effects when accompanied by noise. In Korea, NIHL is the most common occupational disease and has been increasing continuously since the 1990s. The number of claims for compensation has also been increasing steadily. However, the developed country including Korea almost never considered the effects of chemicals on the diagnosis and compensation for hearing loss workers. Occupational hearing loss can be prevented through hearing conservation programs. In this chapter, we will introduce the scientific basis of noise induced hearing loss, the impacts of ototoxic substance and co-existence impact on hearing loss

Nerve-targeted probes for fluorescence-guided intraoperative imaging.

A fundamental goal of many surgeries is nerve preservation, as inadvertent injury can lead to patient morbidity including numbness, pain, localized paralysis and incontinence. Nerve identification during surgery relies on multiple parameters including anatomy, texture, color and relationship to surrounding structures using white light illumination. We propose that fluorescent labeling of nerves can enhance the contrast between nerves and adjacent tissue during surgery which may lead to improved outcomes. Methods: Nerve binding peptide sequences including HNP401 were identified by phage display using selective binding to dissected nerve tissue. Peptide dye conjugates including FAM-HNP401 and structural variants were synthesized and screened for nerve binding after topical application on fresh rodent and human tissue and in-vivo after systemic IV administration into both mice and rats. Nerve to muscle contrast was quantified by measuring fluorescent intensity after topical or systemic administration of peptide dye conjugate. Results: Peptide dye conjugate FAM-HNP401 showed selective binding to human sural nerve with 10.9x fluorescence signal intensity (1374.44 ± 425.96) compared to a previously identified peptide FAM-NP41 (126.17 ± 61.03). FAM-HNP401 showed nerve-to-muscle contrast of 3.03 ± 0.57. FAM-HNP401 binds and highlight multiple human peripheral nerves including lower leg sural, upper arm medial antebrachial as well as autonomic nerves isolated from human prostate. Conclusion: Phage display has identified a novel peptide that selectively binds to ex-vivo human nerves and in-vivo using rodent models. FAM-HNP401 or an optimized variant could be translated for use in a clinical setting for intraoperative identification of human nerves to improve visualization and potentially decrease the incidence of intra-surgical nerve injury

Decreased DBC1 Expression Is Associated With Poor Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer

Purpose The deleted in bladder cancer 1 (DBC1) gene is located within chromosome 9 (9q32-33), a chromosomal region that frequently shows loss of heterozygosity in bladder cancer (BC). It is suspected that it acts as a tumor suppressor gene, but its prognostic value remains unclear. The aim of the present study was to investigate the value of DBC1 as a prognostic marker in BC. Materials and Methods The expression of DBC1 was determined by real-time polymerase chain reaction analysis in 344 patients with BC (220 non-muscle-invasive BC [NMIBC] and 124 muscle-invasive BC [MIBC]) and in 34 patients with normal bladder mucosa. The results were compared with clinicopathologic parameters, and the prognostic value of DBC1 was evaluated by Kaplan-Meier analysis and a multivariate Cox regression model. Results: DBC1 expression was significantly decreased in patients with MIBC compared with those diagnosed with NMIBC (p=0.010). Patients with aggressive tumor characteristics had lower DBC1 expression levels in NMIBC (each, p<0.05). By multivariate Cox regression analysis, low DBC1 expression was a predictor of progression to MIBC (hazard ratio, 7.104; p=0.013). Kaplan-Meier estimates revealed a significant difference in tumor recurrence, progression to MIBC, and cancer-specific survival depending on the level of DBC1 expression in NMIBC (log-rank test, each, p<0.05). Conclusions: The expression of DBC1 was associated with tumor aggressiveness, progression to MIBC, and survival in NMIBC. Our results suggest that DBC1 expression can be a useful prognostic marker for patients with NMIBC

Successful Hemostasis with Recombinant Activated Factor VII in a Patient with Massive Hepatic Subcapsular Hematoma

Recombinant activated coagulation factor VII (rFVIIa) is known to be effective in the management of acquired deficiencies of factor VII and platelet function defects. But recently, rFVIIa has been successfully used to treat ongoing bleeding in disseminated intravascular coagulopathy (DIC) condition. The patient reported here was suspected to be suffering from toxic hepatitis on admission. After percutaneous liver biopsy, bleeding occurred and did not stop even after right hepatic artery embolization. The patient developed a severe hemorrhage that resulted in hypovolemic shock, hemoperitoneum, and a massive subcapsular hematoma. The patient then developed DIC due to massive transfusion, as well as acute liver necrosis. The patient was given 400 μg/kg of rFVIIa. Recombinant factor VIIa was administered in an attempt to control the bleeding. This stabilized the hemoglobin levels of the patient. The patient gradually recovered in 4 months. In conclusion, this case suggests that rFVIIa can be successfully used for the hemostasis of uncontrolled bleeding in DIC

CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii

Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms142561sciescopu

CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii

Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including safe harboring techniques shown in other organisms.

Paclitaxel-loaded poly(lactide-co-glycolide)/poly(ethylene vinyl acetate) composite for stent coating by ultrasonic atomizing spray

The mixture of poly(lactide-co-glycolide) (PLGA) and poly(ethylene vinyl acetate) (PEVA) forms a homogeneous liquid in an organic solvent such as tetrahydrofuran, and a phase-separated PLGA/PEVA composite can be prepared from it by evaporating the organic solvent. Exploiting this phenomenon, we designed a novel method of preparing a drug-loaded PLGA/PEVA composite and used it for coating drug-eluting stents (DESs). Paclitaxel (PTX), an anticancer drug, was chosen as a model drug. PLGA acts as a microdepot for PTX, and PEVA provides mechanical strength to the coating material. The presence of PLGA in the PLGA/PEVA composite suppressed PTX crystallization in the coating material, and PTX showed a sustained release rate over more than 30 days. The mechanical strength of the PLGA/PEVA composite was better than that of PEVA used as a control. After coating the stent with a PLGA/PEVA composite using ultrasonic atomizing spray, the morphology of the coated material was observed by scanning electron microscopy, and the release pattern of PTX was measured by high-performance liquid chromatography

Heat-Killed <i>Enterococcus faecalis</i> Prevents Adipogenesis and High Fat Diet-Induced Obesity by Inhibition of Lipid Accumulation through Inhibiting C/EBP-α and PPAR-γ in the Insulin Signaling Pathway

Increasing consumption of food with high caloric density and a sedentary lifestyle have influenced the increasing obesity prevalence worldwide. The recent pandemic has contributed to this problem. Obesity refers to a state in which lipid accumulates excessively in adipocytes and adipose tissues. Dried heat-killed Enterococcus faecalis (EF-2001) prevents allergic mechanisms, inflammation, and tumor progression. In the present study, we investigated the effects of EF-2001 on high fat diet (HFD)-induced obese rats. The degree of obesity in experimental rats was reduced after 6 weeks of oral administration of 3 mg/kg or 30 mg/kg dosages of EF-2001, indicating regulating effects in rats with HFD-induced obesity. We found that EF-2001 decreased the amounts of total cholesterol, triglyceride, and non-high density lipoprotein (HDL) in HFD-induced obese rats. The effects of EF-2001 on 3T3-L1 adipocytes stained with Oil red O stain are shown in reductions of lipid accumulation, respectively. In addition, we examined the relationships between EF-2001 treatment and mechanisms for the insulin signaling of adipogenesis in 3T3-L1 cells. EF-2001 induced down-regulation in phosphorylation of Erk, JNK, and Akt through the inhibition of insulin receptor phosphorylation. EF-2001 inhibits the expressions of C/EBP-α and PPAR-γ, a lipid metabolism-related transcription factor through confocal microscope observation and Western blot on 3T3-L1 adipocytes and HFD-induced obese rats. Based on our results, intake of EF-2001 significantly prevented HFD-induced obesity in rats through inhibition of C/EBP-α and PPAR-γ in the insulin signaling pathway on lipid accumulation

Timely Event-related synchronization Fading and Phase De-locking and Their Defects in Migraine

Objective To investigate the characteristics of event-related synchronization (ERS) fading and phase de-locking of alpha waves during passive auditory stimulation (PAS) in the migraine patients. Methods The subjects were 16 adult women with migraine and 16 normal controls. Electroencephalographic (EEG) data obtained during PAS with standard (SS) and deviant stimuli (DS) were used. Alpha ERS fading, the phase locking index (PLI) and de-locking index (DLI) were evaluated from the 10 Hz complex Morlet wavelet components at 100 ms (t100) and 300 ms (t300) after PAS. Results At t100, significant ERS was found with SS and DS in the migraineurs and controls (P = 0.000). At t300 in the controls, ERS faded to zero for DS while in the migraineurs there was no fading for DS. In both groups the PLI for SS and DS was significantly reduced, i.e. de-locked, at t300 compared to t100 (P = 0.000). In the migraineurs, the DLI for DS was significantly lower than in the controls (P = 0.003). Conclusion The alpha ERS fading and phase de-locking are defective in migraineurs during passive auditory cognitive processing. Significance The defects in timely alpha ERS fading and in de-locking may play a role in the different attention processing in migraine patients.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2014017262/9SEQ:9PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:3.144FILENAME:timely event-related synchronization fading and phase de-locking and their defects in migraine.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM: