Binaural Speech Discrimination

The phenomenon of binaural summation in which the addition of signals presented to the two ears simultaneously takes place at a central level, has been known for many years. It is reasonable to assume that the pattern of summation differs between subjects with central lesions and those with lesions in the peripheral auditory tracts. Various tests have been proposed to aid in locating the site of the lesion which compare the monaural and binaural speech discrimination scores

In the present work, two of these tests have been examined. Thee group of subjects have been used: (1) a normally hearing group; (2) a group with hearing impairment resulting from cochlea pathology, and (3) a group with hearing impairment resulting from lesions at the level of the cochlear nuclei. The results showed that neither test differentiate between peripheral and cochlear nuclei lesions     

Oxidized dextrins as alternative crosslinking agents for polysaccharides: Application to hydrogels of agarose–chitosan

Hydrogel networks that combine suitable physical and biomechanical characteristics for tissue engineering scaffolds are in demand. The aim of this work was the development of hydrogel networks based on agarose and chitosan using oxidized dextrins as low cytotoxicity crosslinking agents, paying special attention to the study of the influence of the polysaccharide composition and oxidation degree of the dextrins in the final characteristics of the network. The results show that the formation of an interpenetrating or a semi-interpenetrating polymer network was mainly dependent on a minimum agarose content and degree of oxidation of dextrin. Spectroscopic, thermal and swelling analysis revealed good compatibility with an absence of phase separation of polysaccharides at agarose:chitosan proportions of 50:50 and 25:75. The analysis of atomic force microscopy images showed the formation of a fibrillar microstructure whose distribution within the crosslinked chitosan depended mainly on the crosslinker. All materials exhibited the viscoelastic behaviour typical of gels, with a constant storage modulus independent of frequency for all compositions. The stiffness was strongly influenced by the degree of oxidation of the crosslinker. Cellular response to the hydrogels was studied with cells of different strains, and cell adhesion and proliferation was correlated with the homogeneity of the samples and their elastic properties. Some hydrogel formulations seemed to be candidates for tissue engineering applications such as wound healing or soft tissue regeneration.     

非诺贝特对兔脂肪细胞摄取及降解氧化型低密度脂蛋白及CD36表达的影响

为了解非诺贝特对高胆固醇血症兔脂肪细胞摄取及降解氧化型低密度脂蛋白的影响并探讨其可能机制 ,将 10只新西兰大白兔给予高胆固醇饲料饲养 8周后 ,随机分为高胆固醇组和非诺贝特治疗组 ,非诺贝特组在饲以高胆固醇饲料的基础上给予非诺贝特 (每天 30mg kg) ,共 4周。另设普通饮食对照组 5只。实验结束后 ,取皮下脂肪组织行脂肪细胞培养 ,放射配基法测定脂肪细胞对氧化型低密度脂蛋白的摄取及降解 ,半定量逆转录—聚合酶链反应测定脂肪细胞CD36及过氧化体增殖物激活型受体γmRNA的表达。结果发现 ,3组兔脂肪细胞摄取及降解1 2 5Ⅰ 氧化型低密度脂蛋白均呈现一浓度依赖性饱和型曲线 ,高胆固醇组脂肪细胞摄取及降解1 2 5Ⅰ 氧化型低密度脂蛋白明显低于对照组 ;非诺贝特组脂肪细胞摄取及降解1 2 5Ⅰ 氧化型低密度脂蛋白高于高胆固醇组 ,但仍低于对照组 ,3组间比较差异有显著性 (P <0 .0 5 )。逆转录聚合酶链反应发现 ,高胆固醇组过氧化体增殖物激活型受体γ及CD36mRNA表达降低 ,非诺贝特组CD36mRNA表达与对照组相似。以上提示 ,非诺贝特能改善高胆固醇血症兔脂肪细胞摄取及降解1 2 5Ⅰ 氧化型低密度脂蛋白 ,并上调CD36mRNA的表达。     

Epigenetic Role of Histone 3 Lysine Methyltransferase and Demethylase in Regulating Apoptosis Predicting the Recurrence of Atypical Meningioma

Alteration of apoptosis is related with progression and recurrence of atypical meningiomas (AMs). However, no comprehensive study has been conducted regarding histone modification regulating apoptosis in AMs. This study aimed to determine the prognostic values of certain apoptosis-associated factors, and examine the role of histone modification on apoptosis in AMs. The medical records of 67 patients with AMs, as diagnosed during recent 13 yr, were reviewed retrospectively. Immunohistochemical staining was performed on archived paraffin-embedded tissues for pro-apoptotic factors (CASP3, IGFBP, TRAIL-R1, BAX, and XAF1), anti-apoptotic factors (survivin, ERK, RAF1, MDM2, and BCL2), and the histone modifying enzymes (MLL2, RIZ, EZH1, NSD2, KDM5c, JMJD2a, UTX, and JMJD5). Twenty-six (38.8%) patients recurred during the follow-up period (mean duration 47.7 months). In terms of time-to-recurrence (TTR), overexpression of CASP3, TRAIL-R1, and BAX had a longer TTR than low expression, and overexpression of survivin, MDM2, and BCL2 had a shorter TTR than low expression (P<0.05). Additionally, overexpression of MLL2, UTX, and JMJ5 had shorter TTRs than low expression, and overexpression of KDM5c had a longer TTR than low expression. However, in the multi-variate analysis of predicting factors for recurrence, low expression of CASP3 (P<0.001), and BAX (P<0.001), and overexpression of survivin (P=0.007), and MDM2 (P=0.037) were associated with recurrence independently, but any enzymes modifying histone were not associated with recurrence. Conclusively, this study suggests certain apoptosis-associated factors should be associated with recurrence of AMs, which may be regulated epigenetically by histone modifying enzymes.

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HO-1与ox-LDL在大鼠动脉粥样硬化发生中的作用及相关性分析

目的:探讨诱导血红素氧合酶-1(hemeoxygenase-1,HO-1)与氧化低密度脂蛋白(oxidizedlowdensity lipoprotein,ox-LDL)在动脉粥样硬化(atherosclerosis,AS)发生中的作用.方法:利用高脂饮食法建立大鼠动脉粥样硬化模型,40只Wistar大鼠随机均分为4组:对照组(A组)、单纯高脂饲料组(B组)、银杏叶提取物(extract of ginkgo biloba,EGB)组(C组)及锌原卟啉(Zinc protoporphyrinⅨ,ZnPPⅨ)组(D组),应用免疫组织化学染色法检测HO-1蛋白的表达,采用ELISA法测定大鼠血浆中oX-LDL的含量.结果:与A、B、D组相比,C组HO-1蛋白阳性表达程度最强,差异具有统计学意义(P＜0.05);与A、B、C组相比,D组ox-LDL蛋白的含量最高,差异具有统计学意义(P＜0.05);分析动脉粥样硬化中HO-1蛋白表达与ox-LDL含量之间的关系,发现二者呈负相关(P＜0.05).结论:EGB诱导HO-1蛋白的表达抑制ox-LDL表达,而ZnPPⅨ抑制HPO-1蛋白表达促进ox-LDL表达.因此,可以选用HO-1蛋白诱导剂来下调ox-LDL蛋白的表达实现抑制动脉粥样硬化的目的.     

Lipoprotein(a): An independent,genetic, and causal factor for cardiovascular disease and acute myocardial infarction

Lipoprotein(a) [Lp(a)] is a circulating lipoprotein, and its level is largely determined by variation in the Lp(a) gene (LPA) locus encoding apo(a). Genetic variation in the LPA gene that increases Lp(a) level also increases coronary artery disease (CAD) risk, suggesting that Lp(a) is a causal factor for CAD risk. Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), a proatherogenic and proinflammatory biomarker. Lp(a) adversely affects endothelial function, inflammation, oxidative stress, fibrinolysis, and plaque stability, leading to accelerated atherothrombosis and premature CAD. The INTER-HEART Study has established the usefulness of Lp(a) in assessing the risk of acute myocardial infarction in ethnically diverse populations with South Asians having the highest risk and population attributable risk. The 2018 Cholesterol Clinical Practice Guideline have recognized elevated Lp(a) as an atherosclerotic cardiovascular disease risk enhancer for initiating or intensifying statin therapy.     

The impact of antiviral therapy for HCV on kidney disease: a systematic review and meta-analysis

BackgroundControversy persists about the role of hepatitis C as a risk factor for developing kidney disease in the general population. Some authors have evaluated the effect of antiviral therapy for HCV on the risk of kidney disease.Study Aims and DesignA systematic review of the published medical literature was performed to assess whether antiviral therapy for HCV has an independent impact on kidney survival in the adult general population. A random effects model was used to generate an overall estimate of the risk of kidney disease after anti-HCV therapy across the published studies. Meta-regression and stratified analysis were also carried out.ResultsFifteen studies were eligible (n = 356, 285 patients) and separate meta-analyses were conducted according to the outcome. Pooling studies based on viral responses (n = 7; 34,763 individual patients) demonstrated a relationship between sustained viral response and lower frequency of kidney disease; the overall estimate for adjusted risk of kidney disease was 2.50 (95% CI, 1.41; 4.41) (p = 0.0016) and between-study heterogeneity was found (p-value by Q test = 0.004). Aggregation of studies comparing treated vs untreated cohorts (n = 8, n = 333,312 patients) revealed an association between anti-HCV therapy and lower risk of kidney disease. The overall estimate for adjusted risk of kidney disease across the eight studies was 0.39 (95% CI, 0.25; 0.612) (p = 0.0001). Meta-regression showed that the effectiveness of antiviral therapy in reducing the frequency of kidney disease diminishes as cirrhosis (p = 0.02) and HBV infection (p = 0.0001) increase among HCV-infected individuals.ConclusionsAntiviral therapy for HCV lowers the risk of kidney disease among HCV-infected individuals. Studies to understand the mechanisms underlying this association are ongoing.     

类风湿关节炎患者丙二醛修饰型低密度脂蛋白及低密度脂蛋白循环免疫复合物水平分析

目的分析类风湿关节炎患者丙二醛修饰型低密度脂蛋白、低密度脂蛋白循环免疫复合物及血脂水平,探讨其与心血管病高发生率的关系。方法选择类风湿关节炎患者55例,其中合并心血管疾病患者(并发症组)13例,单纯类风湿关节炎患者(单纯组)42例;正常对照组60例。采用酶联免疫吸附试验分别测定血浆丙二醛修饰型低密度脂蛋白和低密度脂蛋白循环免疫复合物水平,同时对受检者血脂和炎症指标进行检测。结果两组类风湿关节炎患者除载脂蛋白B高于对照组外(P<0.05),其它脂质和载脂蛋白水平无明显改变;并发症组与单纯组间脂质和载脂蛋白水平相似。并发症和单纯组血浆丙二醛修饰型低密度脂蛋白(分别为187.81±90.89和102.01±57.73mg/L)和低密度脂蛋白循环免疫复合物水平(分别为2.58±1.69和1.87±0.74AU)均明显高于对照组(分别为32.65±27.00mg/L和1.21±0.38AU,P<0.01),且并发症组高于单纯组(P<0.01或0.05)。低密度脂蛋白循环免疫复合物与C反应蛋白正相关(r=0.301,P=0.026),丙二醛修饰型低密度脂蛋白与血沉趋于相关(r=0.263,P=0.057)。结论类风湿关节炎患者丙二醛修饰型低密度脂蛋白和低密度脂蛋白循环免疫复合物水平显著升高,参与动脉粥样硬化的发生、发展过程。