Abnormal Cholesterol Metabolism and Lysosomal Dysfunction Induce Age-Related Hearing Loss by Inhibiting mTORC1-TFEB-Dependent Autophagy.

Cholesterol is a risk factor for age-related hearing loss (ARHL). However, the effect of cholesterol on the organ of Corti during the onset of ARHL is unclear. We established a mouse model for the ARHL group (24 months, n = 12) and a young group (6 months, n = 12). Auditory thresholds were measured in both groups using auditory brainstem response (ABR) at frequencies of 8, 16, and 32 kHz. Subsequently, mice were sacrificed and subjected to histological analyses, including transmission electron microscopy (TEM), H&E, Sudan Black B (SBB), and Filipin staining, as well as biochemical assays such as IHC, enzymatic analysis, and immunoblotting. Additionally, mRNA extracted from both young and aged cochlea underwent RNA sequencing. To identify the mechanism, in vitro studies utilizing HEI-OC1 cells were also performed. RNA sequencing showed a positive correlation with increased expression of genes related to metabolic diseases, cholesterol homeostasis, and target of rapamycin complex 1 (mTORC1) signaling in the ARHL group as compared to the younger group. In addition, ARHL tissues exhibited increased cholesterol and lipofuscin aggregates in the organ of Corti, lateral walls, and spiral ganglion neurons. Autophagic flux was inhibited by the accumulation of damaged lysosomes and autolysosomes. Subsequently, we observed a decrease in the level of transcription factor EB (TFEB) protein, which regulates lysosomal biosynthesis and autophagy, together with increased mTORC1 activity in ARHL tissues. These changes in TFEB and mTORC1 expression were observed in a cholesterol-dependent manner. Treatment of ARHL mice with atorvastatin, a cholesterol synthesis inhibitor, delayed hearing loss by reducing the cholesterol level and maintaining lysosomal function and autophagy by inhibiting mTORC1 and activating TFEB. The above findings were confirmed using stress-induced premature senescent House Ear Institute organ of Corti 1 (HEI-OC1) cells. The findings implicate cholesterol in the pathogenesis of ARHL. We propose that atorvastatin could prevent ARHL by maintaining lysosomal function and autophagy by inhibiting mTORC1 and activating TFEB during the aging process.

Long-term comparison of the performance of biostimulation and phytoextraction in soil contaminated with diesel and heavy metals.

The long-term remediation performance under the natural conditions is required to establish the appropriate remediation strategy for contaminated soil. The objective of this study was to compare the long-term remediation efficiency of biostimulation and phytoextraction in contaminated soil containing petroleum hydrocarbons (PHs) and heavy metals. Two types of contaminated soil (soil contaminated with diesel only and co-contaminated with diesel and heavy metals) were prepared. For the biostimulation treatments, the soil was amended with compost, whereas maize, a representative phytoremediation plant, was cultivated for the phytoextraction treatments. There was no significant difference in remediation performance of biostimulation and phytoextraction in the diesel-contaminated soil, in which the maximum total petroleum hydrocarbon (TPH) removability was 94-96% (p < 0.05). However, phytoextraction exhibited the higher removability for TPH and heavy metals than biostimulation in the co-contaminated soil. There was no considerable change in the TPH removal in biostimulation (16-25%), while phytoextraction showed a 75% of TPH removal rate in the co-contaminated soil. Additionally, no significant changes were observed in heavy metals concentration of biostimulation, whereas the removability of heavy metals was 33-63% in phytoextraction. Meanwhile, maize, which is a suitable plant for phytoextraction, showed a translocation factor (translocating efficiency from roots to shoots) value of >1. Correlation analysis revealed that soil properties (pH, water content, and organic content) negatively correlated with pollutants removal. Additionally, the soil bacterial communities were changed over the investigated period, and the types of pollutants exerted a significant influence on the bacterial community dynamics. This study performed a pilot-scale comparison of two types of biological remediation technologies under natural environmental conditions and provided information on changes in the bacterial community structures. This study can be useful for establishing appropriate biological remediation methods to restore soil contaminated with PHs and heavy metals.

Dexamethasone Effect on Sudden Hearing Loss is Validated in Stress-induced Animal Models: Hypothetical Study.

BACKGROUND: Stress could be a contributing cause of sudden hearing loss. This study intended to develop an animal model of stress-induced sudden hearing loss and to evaluate the effects of dexamethasone. METHODS: Two stress models (I and II) for rats were designed using various stressors and modified by adjusting the stress protocol to increase the threshold significantly. For the stress model with a significant increase in threshold after stress exposure, changes in cortisol levels according to stress exposure were measured. The threshold shift and the change in the cellular structure associated with stress exposure and dexamethasone administration were analyzed. RESULTS: While hearing thresholds increased only at 16 kHz in rats of stress model I (n=10), the thresholds increased at 16 and 32 kHz in rats of stress model II (n=16). Cortisol level increased after stress exposure (P = .015) in stress model II. Among stress model II rats (stress only and stress+dexamethasone groups), the threshold shift at 16 kHz significantly decreased 1 day after dexamethasone injection in the stress+dexamethasone group (n=8). Histologically, the cochlear cellularity of the stress+dexamethasone group was more compact than that of the stressonly group (n=8). CONCLUSION: Our preliminary study presented the development of an animal model of stress-induced sudden hearing loss and the positive results of steroids in terms of hearing recovery.

Effect of Novosphingobium sp. CuT1 inoculation on the rhizoremediation of heavy metal- and diesel-contaminated soil planted with tall fescue.

Rhizoremediation is a promising method based on the synergism between plant and rhizobacteria to remediate soil co-contaminated with heavy metals and total petroleum hydrocarbons (TPHs). A plant growth-promoting (PGP) rhizobacterium with diesel-degrading capacity and heavy metal tolerance was isolated from the rhizosphere of tall fescue (Festuca arundinacea L.), after which the effects of its inoculation on rhizoremediation performance were evaluated in heavy metal- and diesel-contaminated soil planted with tall fescue. The bacterial isolate (Novosphingobium sp. CuT1) was characterized by its indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and siderophore productivity as PGP traits. CuT1 was able to grow on 1/10 LB-agar plates containing 5 mM of Cu or 5 mM of Pb. To evaluate the remediation effect of heavy metal- and diesel-contaminated soil by CuT1 inoculation, the experimental conditions were prepared as follows. The soil was artificially contaminated with heavy metals (Cu and Pb) at a final concentration of 500 ppm. The soil was then further contaminated with diesel at final concentrations of 0, 10,000, and 30,000 ppm. Finally, all plots were planted with tall fescue, a representative hyperaccumulating plant. Compared to the rhizoremediation performance of the co-contaminated soil (Cu + Pb + diesel) without inoculation, the bioavailable Cu concentrations in the soil and the tall fescue biomass were significantly increased in CuT1 inoculation. Additionally, the root growth of tall fescue was also promoted in CuT1 inoculation. Correlation analysis showed that Cu bioavailability and bioconcentration factor were positively correlated with CuT1 inoculation. The diesel removal efficiency showed a positive correlation with CuT1 inoculation, although the diesel removal was below 30%. CuT1 inoculation was positively correlated with IAA and dehydrogenase activity in the soil. Moreover, the dry biomass of the tall fescue's roots was highly associated with CuT1 inoculation. Collectively, our findings suggest that Novosphingobium sp. CuT1 can be utilized as an applicable bioresource to enhance rhizoremediation performance in heavy metal- and TPH-contaminated soils.

Trends in breast cancer screening rates among Korean women: results from the Korean National Cancer Screening Survey, 2005-2020.

OBJECTIVES: Since 2002, the Korean government has provided breast cancer screening as part of the National Cancer Screening Program. This study reported trends in the screening rate among Korean women from 2005 to 2020, including organized and opportunistic screening for breast cancer. METHODS: Data from the Korean National Cancer Screening Survey, an annual cross-sectional nationwide survey, were collected using a structured questionnaire between 2005 and 2020. The study population included 23,702 women aged 40-74 years with no history of cancer. We estimated the screening rate based on the current recommendation of biennial mammographic screening for breast cancer. In addition, a joinpoint trend analysis was performed for breast cancer screening rates among various subgroups. RESULTS: In 2020, the breast cancer screening rate was 63.5%, reflecting an annual increase of 7.72% (95% confidence interval 5.53 to 9.95) between 2005 and 2012, followed by non-significant trends thereafter. In particular, a significant decrease in the breast cancer screening rate was observed in the subgroups aged 50-59 years old, with 12-15 years of education, and living in rural areas. CONCLUSIONS: Although there has been substantial improvement in breast cancer screening rates in Korean women, the trend has flattened in recent years. Therefore, continual efforts are required to identify subgroups with unmet needs and solve barriers to the uptake of breast cancer screening.

Effect of statin on age-related hearing loss via drug repurposing.

Hearing loss in the elderly cause communication difficulties, decreased quality of life, isolation, loneliness and frustration. The aim of our study was to investigate the effect of drug repurposing candidates in aging mouse. The selected candidate drugs for age-related hearing loss (ARHL) included atorvastatin (AS) and sarpogrelate. Monotherapy or fixed dose combination (FDC) products were administered via oral gavage for 6 consecutive months. Auditory outcomes showed significant hearing preservation in AS-treated aging mice compared to aging control, especially in the early stages of ARHL in both 8 and 16 kHz frequencies. However, none of the FDC products were able to prevent ARHL regardless of AS involvement. In aging mice, damage and dysfunction of mitochondria was noted as well as reactive oxygen species overproduction leading to oxidative stress and intrinsic apoptosis. These processes of ARHL were significantly prevented with administration of AS. Normal structures of mitochondria were maintained, and antioxidant activity were proceeded by activation of HSF1/Sirt1 pathway. Our study suggests that AS is a promising drug repurposing candidate to delay the progression of ARHL.

Impact of COVID-19 on cancer screening in South Korea.

The coronavirus disease (COVID-19) pandemic significantly declined cancer screening rates worldwide. Its impact on the South Korean population is unclear, depending on socioeconomic status (SES), residence, and history of chronic disease. This study utilized data (2018-2020) from the Korean National Cancer Screening Survey, an annual cross-sectional study employing nationally representative random sampling. Cancer screening rates were defined as the proportion of the eligible population who received respective cancer screening within the last 1 year and investigated four major cancers (stomach, colorectal, breast, and cervical). Screening rates every year were compared with screening rate ratios (SRRs) and the corresponding 95% confidence intervals (CIs). Between 2019 and 2020, screening rates declined significantly by 23%, 17%, 12%, and 8% for colorectal cancer (SRR 0.77; 95% CI 0.73-0.82), stomach cancer (SRR 0.83; 95% CI 0.79-0.87), breast cancer (SRR 0.88; 95% CI 0.82-0.93), and cervical cancer (SRR 0.92; 95% CI 0.87-0.97), respectively. Regardless of cancer type, screening was significantly lower in metropolitan residents, those with higher SES, and, interestingly, those without a history of chronic diseases. The significant decline in cancer screening during the pandemic requires urgent political intervention to reduce the burden of future cancer incidence and mortality.

Changes in cancer screening before and during COVID-19: findings from the Korean National Cancer Screening Survey 2019 and 2020.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has negatively affected every aspect of medical care. However, information regarding the impact of the pandemic on cancer screening is lacking. This study aimed to explore cancer screening changes by geographic region before and during the pandemic in Korea. METHODS: Korean National Cancer Screening Survey data for 2019 and 2020 were used. Changes in the screening rate before and during the COVID-19 pandemic were calculated by subtracting the rate in 2020 from the rate in 2019. Multivariate logistic regression analyses examined the differences in screening rates at the national and 16 provincial levels before and after the COVID-19 outbreak. RESULTS: The 1-year screening rates for the four types of cancer decreased during the pandemic (stomach cancer: -5.1, colorectal cancer: -3.8, breast cancer: -2.5, cervical cancer: -1.5%p). In metropolitan areas, the odds of undergoing screening tests during the pandemic were significantly lower than before the pandemic for stomach (adjusted odds ratio [aOR], 0.66; 95% confidence interval [CI], 0.56 to 0.76), colorectal (aOR, 0.63; 95% CI, 0.50 to 0.79), and breast cancers (aOR, 0.75; 95% CI, 0.60 to 0.94). Furthermore, the likelihood of undergoing stomach cancer screening during the pandemic was significantly lower than before the pandemic in non-metropolitan urban areas (aOR, 0.81; 95% CI, 0.70 to 0.94), while it was higher in rural areas (aOR, 1.54; 95% CI, 1.10 to 2.16). CONCLUSIONS: Since the COVID-19 pandemic, the cancer screening rate has decreased significantly, especially in large cities. Public health efforts are required to improve cancer screening rates.

Trends of Colorectal Cancer Screening Rates in Korea: Korean National Cancer Screening Survey 2005-2020.

Background/Aims: Screening for colorectal cancer (CRC) is important in reducing the morbidity and mortality of CRC. Thus, this study aimed to describe the trends of CRC screening in both organized and opportunistic settings in Korea from 2005 to 2020 according to sociodemographic characteristics. Methods: This study analyzed the data of adults aged 50 to 74 years from the Korean National Cancer Screening Survey. Trends for CRC screening rates (fecal immunochemical test [FIT] within the last year, double-contrast barium enema within the last 5 years, or colonoscopy within the last 10 years for 2005-2018 and FIT within the last year or colonoscopy within the last 10 years for 2019-2020) were analyzed using Joinpoint regression. The trends were also analyzed according to sociodemographic characteristics, including age, sex, monthly household income, education level, and residential area. Results: A total of 29,040 participants were included in the analysis. The CRC screening rate significantly increased from 25.0% to 60.1%, with an annual percent change (APC) of 9.2% between 2005 and 2014, followed by a nonsignificant increase to 64.4% between 2014 and 2020 (APC,1.7%). When the participants were stratified according to sociodemographic factors, the participants with higher household income and education levels generally had higher screening rates. Conclusions: There has been substantial improvement in CRC screening rates in the general Korean population. However, it is necessary to determine why the screening rate has stabilized since 2014 and identify barriers that cause disparities in CRC screening rates among populations with lower socioeconomic status.

Seasonal Dynamics of Bacterial Community Structure in Diesel Oil-Contaminated Soil Cultivated with Tall Fescue (Festuca arundinacea).

The objective of this study was to explore the seasonal characteristics of rhizoremediation and the bacterial community structure over the course of a year in soil contaminated with diesel oil. The soil was contaminated with diesel oil at a total petroleum hydrocarbon (TPH) concentration of 30,000 mg-TPH·kg-soil-1. Tall fescue seedlings were planted in the contaminated soil and rhizoremediation performance was monitored for 317 days. The TPH concentration gradually declined, reaching 75.6% after day 61. However, the TPH removability decreased by up to 30% after re-contamination in the fall and winter. The bacterial community structure exhibited distinct seasonal dynamics. Genus Pseudomonas significantly increased up to 55.7% in the winter, while the genera Immundisolibacter and Lysobacter, well-known petroleum hydrocarbon (PH)-degrading bacteria, were found to be positively linked to the TPH removal rate. Consequently, knowledge of this seasonal variation in rhizoremediation performance and the bacterial community structure is useful for the improvement of rhizoremediation in PH-contaminated environments.

Development of Intracorporeal Differentiation of Stem Cells to Induce One-Step Mastoid Bone Reconstruction during Otitis Media Surgeries.

Mastoidectomy is a surgical procedure for the treatment of chronic otitis media. This study investigated the ability of rat stromal vascular fraction cells (rSVF) in combination with polycaprolactone (PCL) scaffolds and osteogenic differentiation-enhancing blood products to promote the regeneration of mastoid bone defect. Twenty male Sprague Dawley rats were randomly divided according to obliteration materials: (1) control, (2) PCL scaffold only, (3) rSVFs + PCL, (4) rSVFs + PCL + platelet-rich plasma, and (5) rSVFs + PCL + whole plasma (WP). At 7 months after transplantation, the rSVFs + PCL + WP group showed remarkable new bone formation in the mastoid. These results indicate that SVFs, PCL scaffolds, and blood products accelerate bone regeneration for mastoid reconstruction. Autologous SVF cells with PCL scaffolds and autologous blood products are promising composites for mastoid reconstruction which can be easily harvested after mastoidectomy. With this approach, the reconstruction of mastoid bone defects can be performed right after mastoidectomy as a one-step procedure which can offer efficiency in the clinical field.

Trends in cervical cancer screening rates among Korean women: results of the Korean National Cancer Screening Survey, 2005-2020.

OBJECTIVE: This study aimed to analyze the trends in cervical cancer screening rates, including organized and opportunistic cancer screening rates, with the Papanicolaou test among Korean women. METHODS: Data were collected from a nationwide, cross-sectional, Korean National Cancer Screening Survey. To evaluate the cervical cancer screening rates, we used the screening approach of "cervical cancer screening rate with recommendation," defined as the proportion of women who underwent the Papanicolaou test during the previous 2 years according to the Protocol of National Cancer Screening Program for Cervical Cancer in Korea. The joinpoint regression analysis, which describes the annual percent change (APC), was performed to detect significant changes in cervical cancer screening rates in women aged 30-74 years during 2005-2020. RESULTS: The cervical cancer screening rate was 56.0% in 2020. From 2005 to 2013, there was a rising trend in cervical cancer screening rates (APC=2.70%, 95% confidence interval [CI]:1.05 to 4.38), followed by a falling trend (APC=-2.67%, 95% CI:-4.3 to -1.01). The falling trend was significantly associated with age (≥40 years), education level (below the 15th grade), household income (below the middle-income level), and residence (all residential areas). CONCLUSION: The recent falling trend was more common in women with a low socioeconomic status, which suggests that there is a socioeconomic gap in cervical cancer screening. Moreover, young women in their thirties had a low screening rate. Therefore, an active participation strategy for women vulnerable to cervical cancer is required.

Heat Shock Factor 1 Prevents Age-Related Hearing Loss by Decreasing Endoplasmic Reticulum Stress.

Endoplasmic reticulum (ER) stress is a common stress factor during the aging process. Heat shock factor 1 (HSF1) plays a critical role in ER stress; however, its exact function in age-related hearing loss (ARHL) has not been fully elucidated. The purpose of the present study was to identify the role of HSF1 in ARHL. In this study, we demonstrated that the loss of inner and outer hair cells and their supporting cells was predominant in the high-frequency region (basal turn, 32 kHz) in ARHL cochleae. In the aging cochlea, levels of the ER stress marker proteins p-eIF2α and CHOP increased as HSF1 protein levels decreased. The levels of various heat shock proteins (HSPs) also decreased, including HSP70 and HSP40, which were markedly downregulated, and the expression levels of Bax and cleaved caspase-3 apoptosis-related proteins were increased. However, HSF1 overexpression showed significant hearing protection effects in the high-frequency region (basal turn, 32 kHz) by decreasing CHOP and cleaved caspase-3 and increasing the HSP40 and HSP70 proteins. These findings were confirmed by HSF1 functional studies using an auditory cell model. Therefore, we propose that HSF1 can function as a mediator to prevent ARHL by decreasing ER stress-dependent apoptosis in the aging cochlea.

Dynamics of bacterial functional genes and community structures during rhizoremediation of diesel-contaminated compost-amended soil.

The objective of this study was to characterize the effects of organic soil amendment (compost) on bacterial populations associated with petroleum hydrocarbon (PH) degradation and nitrous oxide (N2O) dynamics via pot experiments. Soil was artificially contaminated with diesel oil at total petroleum hydrocarbon (TPH) concentration of 30,000 mg·kg-soil-1 and compost was mixed with the contaminated soil at a 1:9 ratio (w/w). Maize seedlings were planted in each pot and a total of ten pots with two treatments (compost-amended and unamended) were prepared. The pot experiment was conducted for 85 days. The compost-amended soil had a significantly higher TPH removal efficiency (51.1%) than unamended soil (21.4%). Additionally, the relative abundance of the alkB gene, which is associated with PH degradation, was higher in the compost-amended soil than in the unamended soil. Similarly, cnorB and nosZ (which are associated with nitric oxide (NO) and N2O reduction, respectively) were also highly upregulated in the compost-amended soil. Moreover, the compost-amended soil exhibited higher richness and evenness indices, indicating that bacterial diversity was higher in the amended soil than in the unamended soil. Therefore, our findings may contribute to the development of strategies to enhance remediation efficiency and greenhouse gas mitigation during the rhizoremediation of diesel-contaminated soils.

Effect of upflow and downflow baffle configuration on particulate matter removal in a mirror-symmetrical multi-compartment scrubber.

Control over particulate matter (PM) emission from grilling is required for improving public health and air quality. The performance of mirror-symmetrical multi-compartment scrubbers with an upflow (U-type) and downflow baffle (D-type) configuration was evaluated for PM emission control from grilling at a flow rate of 30 m3 min-1. The PM removal efficiency of the U-type scrubber was the highest when the water level was 8 cm (95.6%), and the pressure drops recorded at the water levels of 6, 8 and 10 cm were 103, 122 and 153 mmH2O, respectively. Although PM removal efficiency of the D-type scrubber was over 91.0% at the water levels of 8, 10 and 12 cm, the pressure drops were 124, 142 and 185 mmH2O, respectively. A comprehensive evaluation of the water volume, pressure drop and PM removal performance, as well as device size, revealed that the U-type scrubber with a PM removal efficiency of 92% or higher and a pressure drop of 122 mmH2O or lower at the water levels of 6-8 cm was more economical for removing PM from grilling gas than the D-type scrubber.

Trends in Cancer Screening Rates among Korean Men and Women: Results of the Korean National Cancer Screening Survey, 2004-2018.

PURPOSE: The Korean National Cancer Screening Survey (KNCSS) is a nationwide annual cross-sectional survey conducted for the past 15 years. This study aimed to report trends in the overall screening rates of both organized and opportunistic cancer screening programs from 2004-2018. MATERIALS AND METHODS: KNCSS data were collected using a structured questionnaire. For five major cancers (i.e., stomach, liver, colorectal, breast, and cervical cancer), we evaluated both the lifetime screening rate and the screening rate with recommendations. The study population included men aged 40-74 years and women aged 20-74 years with no cancer histories. RESULTS: Screening rate with recommendations increased from 2004 annually by 4.4% and 1.5% until 2013 for stomach and liver cancers, respectively, by 4.0% until 2012 for breast cancer, and by 3.6% and 1.2% until 2014 for colorectal and cervical cancers, respectively, followed by nonsignificant trends thereafter. In 2018, screening rates with recommendations for these cancers were 72.8%, 26.2%, 63.1%, 58.4%, and 55.6%, respectively. CONCLUSION: Screening rates for the five types of cancer demonstrated a marked increase between 2004 and 2018. However, many recent screening rates have been flattened with nonsignificant trends, and there are lower rates for cervical cancer screening among young age groups. Steady efforts are needed to achieve higher screening participation rates overall, especially for the cervical cancer screening of young women in their 20s.

Impact of Awareness of Breast Density on Perceived Risk, Worry, and Intentions for Future Breast Cancer Screening among Korean Women.

PURPOSE: This study sought to examine perceived risk and concerns for breast cancer according to awareness of breast density and states thereof among Korea women and to identify the impact of such awareness on screening intentions. MATERIALS AND METHODS: This study was based on the 2017 Korean National Cancer Screening Survey of a nationally representative and randomly selected sample of Koreans. Ordinal logistic regression was conducted to examine associations for awareness of and knowledge on breast density in relation to psychological factors. Multivariate logistic regression analyses were conducted to investigate significant factors associated with intentions to undergo breast cancer screening. RESULTS: Among a total of 1,609 women aged 40-69 years, 62.0% were unaware of their breast density, and only 29.7% had good breast density knowledge. Awareness of one's breast density and knowledge about breast density were positively associated with perceptions of absolute and comparative risk and cancer worry. Women aware of their breast density (adjusted odds ratio [aOR], 1.35 for women aware of having a non-dense breast; aOR, 4.17 for women aware of having a dense breast) and women with a good level of breast density knowledge (aOR, 1.65) were more likely to undergo future breast cancer screening. CONCLUSION: Breast density awareness and knowledge showed positive associations with psychological factors and breast cancer screening intentions. However, the majority of Korean women were not aware of their breast density status and demonstrated poor knowledge about breast density. These results demonstrate a need for better health communication concerning breast density.

Evaluation of rhizoremediation and methane emission in diesel-contaminated soil cultivated with tall fescue (Festuca arundinacea).

Rhizoremediation, CH4 emission, and bacterial community dynamics were evaluated in diesel-contaminated soil cultivated with tall fescue via a pot experiment. At the beginning of the experiment, total petroleum hydrocarbons (TPHs) removal efficiency was 30.2% in tall fescue-cultivated soil, which was significantly higher than that of unplanted soil (19.4%). However, when compost was added as a soil amendment, TPHs removal efficiency increased to 39.2% in tall fescue-cultivated soil. Interestingly, potential CH4 emissions were more affected by the initial diesel concentration than by compost addition or tall fescue planting. Specifically, the potential CH4 emission was approximately 3.8 times higher in the treatment with the highest initial diesel concentration (T-WC38) than that of the treatment with the lowest initial diesel concentration (T-WC5). Functional gene analysis revealed that TPHs removal had a linear correlation with the alkB/16S gene ratio, whereas potential CH4 emission had a linear correlation with pmoA gene copy numbers. Initial diesel concentrations in soil also affected bacterial community structures and the genera Rhizobium, Halothiobacillus, and Geobacter were found to be positively linked to diesel-contaminated soil rhizoremediation. Therefore, this study provides useful insights into the development of strategies to enhance rhizoremediation efficiency and CH4 emission mitigation in diesel-contaminated soils.

Type 1 Diabetes Induces Hearing Loss: Functional and Histological Findings in An Akita Mouse Model.

The relationship between type 1 diabetes and hearing loss is not well known, although based on many pathological studies, type 2 diabetes induced hearing loss is associated with microcirculation problems in the inner ear. The purpose of this study was to investigate the correlation between type 1 diabetes and hearing loss through hearing function and immunohistochemical analyses using type 1 diabetic Akita or wild-type (WT) mice. The Akita mice had a significant increase in hearing thresholds, blood glucose, and insulin tolerance compared to WT mice. Histological analysis showed that the loss of cells and damage to mitochondria in the spiral ganglion neurons of Akita mice were significantly increased compared to WT. Also, the stria vascularis showed decreased thickness, loss of intermediate cells, and disturbance in blood capillary shape in the Akita mice. Moreover, a reduction in type I, II, and IV fibrocytes and Na+/K+-ATPase α1 expression in spiral ligament was also observed. Cleaved caspase-3 expression was highly expressed in spiral ganglion neurons. In conclusion, hearing loss in type 1 diabetes is caused not only by ion imbalance and blood flow disorders of cochlear endolymph, but through the degenerative nervous system via apoptosis-mediated cell death.

Atorvastatin prevents hearing impairment in the presence of hyperlipidemia.

It is known that hyperlipidemia is a risk factor for sensorineural hearing loss. However, the biological mechanisms underlying hyperlipidemia and hearing impairment have not been completely elucidated in the cochlea. Based on our previous study of human subjects, elderly people taking drugs for hyperlipidemia showed better hearing than those not taking any medications. We hypothesized that drugs for hyperlipidemia, such as statins, may have the potential to prevent hearing impairment. The aim of this study was to investigate the correlation between hyperlipidemia and hearing impairment and the hearing preservation effect of atorvastatin using a hyperlipidemic mouse model with diet-induced obesity (DIO). Here, we demonstrate that DIO mice had a significant hearing impairment as well as increased levels of reactive oxygen species (ROS) and hair cell death due to reduced levels of pAKT and superoxide dismutase 2 (SOD2). However, these changes were significantly prevented by atorvastatin. Oxidative stress-induced intrinsic apoptosis was decreased by the high expression of Nrf2 and antioxidant genes, which improved mitochondrial function and ROS via activation of the PI3K-pAKT pathway by atorvastatin. Therefore, atorvastatin has the potential to prevent hearing impairment via redox balance in the presence of hyperlipidemia.