Effect of tinnitus on sound localization ability in patients with normal hearing

Abstract Objectives To determine whether tinnitus negatively impacts the accuracy of sound source localization in participants with normal hearing. Methods Seventy-five participants with tinnitus and 74 without tinnitus were enrolled in this study. The accuracy of sound source discrimination on the horizontal plane was compared between the two participant groups. The test equipment consisted of 37 loudspeakers arranged in a 180° arc facing forward with 5° intervals between them. The stimuli were pure tones of 0.25, 0.5, 1, 2, 4, and 8 kHz at 50 dB SPL. The stimuli were divided into three groups: low frequency (LF: 0.25, 0.5, and 1 kHz), 2 kHz, and high frequency (HF: 4 and 8 kHz) stimuli. Results The Root Mean Square Error (RMSE) score of all the stimuli in the tinnitus group was significantly higher than that in the control group (13.45 ± 3.34 vs. 11.44 ± 2.56, p = 4.115, t < 0.001). The RMSE scores at LF, 2 kHz, and HF were significantly higher in the tinnitus group than those in the control group (LF: 11.66 ± 3.62 vs. 10.04 ± 3.13, t = 2.918, p = 0.004; 2 kHz: 16.63 ± 5.45 vs. 14.43 ± 4.52, t = 2.690, p = 0.008; HF: 13.42 ± 4.74 vs. 11.14 ± 3.68, t = 3.292, p = 0.001). Thus, the accuracy of sound source discrimination in participants with tinnitus was significantly worse than that in those without tinnitus, despite the stimuli frequency. There was no difference in the ability to localize the sound of the matched frequency and other frequencies (12.86 ± 6.29 vs. 13.87 ± 3.14, t = 1.204, p = 0.236). Additionally, there was no correlation observed between the loudness of tinnitus and RMSE scores (r = 0.096, p = 0.434), and the Tinnitus Handicap Inventory (THI) and RMSE scores (r = −0.056, p = 0.648). Conclusions Our present data suggest that tinnitus negatively impacted sound source localization accuracy, even when participants had normal hearing. The matched pitch and loudness and the impact of tinnitus on patients' daily lives were not related to the sound source localization ability. Level of evidence 4.

Effect of tinnitus on sound localization ability in patients with normal hearing.

OBJECTIVES: To determine whether tinnitus negatively impacts the accuracy of sound source localization in participants with normal hearing. METHODS: Seventy-five participants with tinnitus and 74 without tinnitus were enrolled in this study. The accuracy of sound source discrimination on the horizontal plane was compared between the two participant groups. The test equipment consisted of 37 loudspeakers arranged in a 180° arc facing forward with 5° intervals between them. The stimuli were pure tones of 0.25, 0.5, 1, 2, 4, and 8kHz at 50dB SPL. The stimuli were divided into three groups: low frequency (LF: 0.25, 0.5, and 1kHz), 2kHz, and high frequency (HF: 4 and 8kHz) stimuli. RESULTS: The Root Mean Square Error (RMSE) score of all the stimuli in the tinnitus group was significantly higher than that in the control group (13.45±3.34 vs. 11.44±2.56, p=4.115, t<0.001). The RMSE scores at LF, 2kHz, and HF were significantly higher in the tinnitus group than those in the control group (LF: 11.66±3.62 vs. 10.04±3.13, t=2.918, p=0.004; 2kHz: 16.63±5.45 vs. 14.43±4.52, t=2.690, p=0.008; HF: 13.42±4.74 vs. 11.14 ±3.68, t=3.292, p=0.001). Thus, the accuracy of sound source discrimination in participants with tinnitus was significantly worse than that in those without tinnitus, despite the stimuli frequency. There was no difference in the ability to localize the sound of the matched frequency and other frequencies (12.86±6.29 vs. 13.87±3.14, t=1.204, p=0.236). Additionally, there was no correlation observed between the loudness of tinnitus and RMSE scores (r=0.096, p=0.434), and the Tinnitus Handicap Inventory (THI) and RMSE scores (r=-0.056, p=0.648). CONCLUSIONS: Our present data suggest that tinnitus negatively impacted sound source localization accuracy, even when participants had normal hearing. The matched pitch and loudness and the impact of tinnitus on patients' daily lives were not related to the sound source localization ability.

Assessment of heavy metal contamination in the atmospheric deposition during 1950-2016 A.D. from a snow pit at Dome A, East Antarctica.

Antarctic trace element records could provide important insights into the impact of human activities on the environment over the past few centuries. In this study, we investigated the atmospheric concentrations of 14 representative heavy metals (Al, As, Cd, Co, Cu, Fe, K, Mg, Mn, Pb, Sb, Sr, Tl and V) from 174 samples collected in a 4-m snow pit at Dome Argus (Dome A) on the East Antarctic Plateau, covering the period from 1950 to 2016 A.D. We found great variability in the annual concentration of all metals. The crustal enrichment factors suggest that the concentrations of some heavy metals (Cd, Sb, Cu, As and Pb) were likely influenced by anthropogenic activities in recent decades. An analysis of source regions suggests that heavy metal pollution at Dome A was largely caused by human activities in Australia and South America (e.g. mining production, leaded gasoline). Based on the relationship between the trace elements fluxes and sea ice concentration (SIC), sea surface temperature (SST) and annual mean air temperature at 2 m above the ground (T2m), our analysis shows that deposition and transport of atmospheric aerosol at Dome A were influenced by circum-Antarctic atmospheric circulations.

Protective effect of dexmedetomidine on perioperative myocardial injury in patients with Stanford type-A aortic dissection.

OBJECTIVE: To investigate the protective effect and mechanism of dexmedetomidine (Dex) on perioperative myocardial injury in patients with Stanford type-A aortic dissection (AD). METHODS: Eighty-six patients with Stanford type-A AD were randomly divided into Dex and control groups, with 43 cases in each group. During the surgery, the control group received the routine anesthesia, and the Dex group received Dex treatment based on routine anesthesia. The heart rate (HR) and mean arterial pressure (MAP) were recorded before Dex loading (t0), 10 min after Dex loading (t1), at the skin incision (t2), sternum sawing (t3), before cardiopulmonary bypass (t4), at the extubation (t5), and at end of surgery (t6). The blood indexes were determined before anesthesia induction (T0) and postoperatively after 12h (T1), 24h (T2), 48h (T3), and 72h (T4). RESULTS: At t2 and t3, the HR and MAP in the Dex group were lower than in the control group (P < 0.05). Compared with the control group, in the Dex group at T1, T2, and T3, the serum creatine kinase-MB, cardiac troponin-I, C-reactive protein, and tumor necrosis factor-α levels were decreased, and the interleukin-10 level, the serum total superoxide dismutase, and total anti-oxidant capability increased, while the myeloperoxidase and malondialdehyde levels decreased (all P < 0.05). CONCLUSIONS: Dex treatment may alleviate perioperative myocardial injury in patients with Stanford type-A AD by resisting inflammatory response and oxidative stress.

Protective effect of dexmedetomidine on perioperative myocardial injury in patients with Stanford type-A aortic dissection

SUMMARY OBJECTIVE: To investigate the protective effect and mechanism of dexmedetomidine (Dex) on perioperative myocardial injury in patients with Stanford type-A aortic dissection (AD). METHODS: Eighty-six patients with Stanford type-A AD were randomly divided into Dex and control groups, with 43 cases in each group. During the surgery, the control group received the routine anesthesia, and the Dex group received Dex treatment based on routine anesthesia. The heart rate (HR) and mean arterial pressure (MAP) were recorded before Dex loading (t0), 10 min after Dex loading (t1), at the skin incision (t2), sternum sawing (t3), before cardiopulmonary bypass (t4), at the extubation (t5), and at end of surgery (t6). The blood indexes were determined before anesthesia induction (T0) and postoperatively after 12h (T1), 24h (T2), 48h (T3), and 72h (T4). RESULTS: At t2 and t3, the HR and MAP in the Dex group were lower than in the control group (P < 0.05). Compared with the control group, in the Dex group at T1, T2, and T3, the serum creatine kinase-MB, cardiac troponin-I, C-reactive protein, and tumor necrosis factor-α levels were decreased, and the interleukin-10 level, the serum total superoxide dismutase, and total anti-oxidant capability increased, while the myeloperoxidase and malondialdehyde levels decreased (all P < 0.05). CONCLUSIONS: Dex treatment may alleviate perioperative myocardial injury in patients with Stanford type-A AD by resisting inflammatory response and oxidative stress.

RESUMO OBJETIVO: Investigar o efeito protetor e o mecanismo da dexmedetomidina (Dex) na lesão perioperativa do miocárdio em doentes com dissecação aórtica Tipo A de Stanford (AD). MÉTODOS: Oitenta e seis pacientes com o Tipo A de Stanford foram aleatoriamente divididos em Dex e grupos de controle, 43 casos em cada grupo. Durante a cirurgia, o grupo de controle recebeu a anestesia de rotina, e o grupo Dex recebeu tratamento Dex baseado na anestesia de rotina. A frequência cardíaca (AR) e a pressão arterial média (MAP) foram registradas no momento anterior ao Dex carregar (t0), 10 minutos após o Dex carregar (t1), incisão cutânea (t2), serragem de esterno (t3), antes do bypass cardiopulmonar (t4), extubação (t5) e fim da cirurgia (t6). Os índices de sangue foram determinados no momento antes da indução da anestesia (T0) e no pós-operatório 12 horas (T1), 24 horas (T2), 48 horas (T3) e 72 horas (T4). RESULTADOS: Em T2 e t3, o RH e o MAP do grupo Dex foram inferiores ao grupo de controle (p<0,05). Em comparação com o grupo de controle, no grupo Dex em T1, T2 e T3, os níveis séricos de creatina quinase-MB, troponina-I, proteína C-reativa e necrose do fator-α do tumor diminuíram, o nível interleucina-10 aumentou, o desalinhamento total do superóxido sérico e a capacidade antioxidante total aumentaram e os níveis de mielopeperóxido e malondialdeído diminuíram (todos p<0,05). CONCLUSÃO: O tratamento com Dex pode aliviar a lesão do miocárdio perioperativo em doentes com o Tipo A de Stanford por resistência à resposta inflamatória e ao estresse oxidativo.

Activation of aryl hydrocarbon receptor dissociates fatty liver from insulin resistance by inducing fibroblast growth factor 21.

UNLABELLED: The aryl hydrocarbon receptor (AHR), also known as the dioxin receptor, was originally characterized as a xenobiotic receptor that senses xenotoxicants. We investigated the endobiotic and hepatic role of AHR in fatty liver and energy metabolism and identified the endocrine factor that mediates the metabolic function of AHR. Wild-type and liver-specific constitutively activated human AHR transgenic mice were used to investigate the role of AHR in fatty liver and energy homeostasis. Adenovirus expressing short hairpin RNA targeting fibroblast growth factor 21 (FGF21) were used to determine the involvement of FGF21 in the metabolic effect of AHR. We showed that, despite their severe fatty liver, the transgenic mice were protected from diet-induced obesity and type 2 diabetes. We identified the endocrine hormone FGF21 as a mediator for the metabolic benefit of AHR and established FGF21 as a direct transcriptional target of AHR. Interestingly, the transactivation of FGF21 by AHR contributed to both hepatic steatosis and systemic insulin hypersensitivity, both of which were largely abolished upon FGF21 knockdown. CONCLUSIONS: The AHR-FGF21 endocrine signaling pathway establishes AHR as a pivotal environmental modifier that integrates signals from chemical exposure in the regulation of lipid and energy metabolism.

Anatomy basis and clinical significance of various types of abductor hallucis superior margin arterial arcades / Bases anatómicas e importancia clínica de varios tipos de arcos arteriales del margen superior del músculo abductor del hálux

The aim of this study was to group arteries of arterial arch at the superior margin of the abductor hallucis muscle according to their constitutes and provide anatomical basis for reverse bifolicated flap based on it. The constitute, track-way and distribution of the artery, which supply the medial pedis flap, the medial plantar and the medial tarsal flap, especial the arterial arch at the superior margin of the abductor hallucis muscle were observed and analyzed on 81 lower limbs cast specimens and 2 fresh feet specimens. According to their constitute, arterial arch at the superior margin of the abductor hallucis muscle can be classified into 3 types: i) type I, It was constituted mainly by the branch of anterior medial malleolus artery and (or) the medial tarsal artery. ii) type II, It was constituted mainly by the superficial branch of the medial plantar artery; iii) type II, It was constituted mainly by the branch of anterior medial malleolus artery and the branch of medial tarsal artery anastomose with the superficial branch of the medial plantar artery, which was divided into two subtypes according to the different anastomosis of the artery: Type III 1, the type of anastomosed directly was about 48.2 percent, type III 2, The type of anastomosed indirectly was about 24.1 percent. According to the constitute of arterial arch at the superior margin of the abductor hallucis muscle can be classified into three types: The type of anterior medial malleolus artery and medial tarsal artery, the type of superficial branch of the medial plantar artery and the type of mixed. For the type mixed, two subtypes can be classified according to the different anastomosis of the artery.

El objetivo fue clasificar las arterias de arco arterial del margen superior del músculo abductor del hálux según su constitución, y proporcionar una base anatómica para el colgajo bilobulado reverso basado en él. La constitución, recorrido y distribución de las arterias que suministran los colgajos pedicular medial, plantar medial y medial del tarso, en especial el arco arterial del margen superior del músculo abductor del hálux fueron observados y analizados en 81 modelos de miembros inferiores y 2 pies frescos. De acuerdo con su constitución, el arco arterial del margen superior del músculo abductor del hálux se pueden clasificar en 3 tipos: i) tipo I, constituido principalmentepor la rama de la arteria anterior del maléolo medial y/o la arteria medial del tarso. ii) tipo II, constituido principalmente por la rama superficial de la arteria plantar medial, iii) tipo III constituido principalmente por la rama de la arteria maleolar medial anterior y la rama de la anastomosis de la arteria tarsiana medial de la rama superficial de la arteria plantar medial, que se divide en 2 subtipos diferentes de acuerdo con el tipo de anastomosis: tipo III 1, una anastomosis directa que se observó en el 48,2 por ciento, y tipo III 2, una anastomosis indirecta observada en aproximadamente el 24,1 por ciento de los casos. Según la constitución, el arco arterial del margen superior del músculo abductor del hálux se puede clasificar en 3 tipos: el tipo de arteria anterior del maléolo medial y la arteria tarsiana medial, el tipo de rama superficial de la arteria plantar medial y el tipo mixto. En el tipo mixto, pueden ser clasificados 2 subtipos de acuerdo a la diferente anastomosis de la arteria.