Col11a1 and col11a2 mRNA expression in the developing mouse Cochlea: Implications for the correlation of hearing loss phenotype with mutant type XI collagen genotype

Objective Mutations in the fibrillar collagen genes COL11A1 and COL11A2 can cause sensorineural hearing loss associated with Stickler syndrome. There is a correlation of hearing loss severity, onset, progression and affected frequencies with the underlying mutated collagen gene. We sought to determine whether differences in spatial or temporal expression of these genes underlie this correlation, and to identify the cochlear cell populations expressing these genes and the structures likely to be affected by mutations.

Materials and Methods We used in situ hybridization analysis of C57BL/6J mouse temporal bones.

Results Similar, diffuse expression of Col11a1 and Col11a2 mRNA was first observed in the cochlear duct at embryonic Day 15.5, with increasingly focal hybridization being noted at postnatal Days 1 and 5 in the greater epithelial ridge and lateral wall of the cochlea. The greater epithelial ridge appeared to be the main, if not only, source of mRNA encoding Col11a1 and Col11a2 in the tectorial membrane. At postnatal Day 13, Col11a1 and Col11a2 expression became more focal and co-localized in the inner sulcus, Claudius’ cells and cells of Boettcher.

Conclusions We did not observe spatial or temporal differences in mRNA expression that could account for the auditory phenotype–genotype correlation. The expression patterns suggest essential roles for Col11a1 and Col11a2 in the basilar or tectorial membranes.     

葛根素注射液联合巴曲酶治疗突发性耳聋的临床疗效观察

目的 研究葛根素注射液联合巴曲酶治疗突发性耳聋的临床效果。方法 选择2016年2月—2016年12月在榆林市星元医院进行诊治的突发性耳聋患者78例，随机分为两组，每组各39例。对照组给予巴曲酶注射液，每次10 BU，加入500 mL生理盐水中稀释后进行静脉滴注，每两天1次。观察组在对照组基础上联合静脉滴注葛根素注射液治疗，将0.4 g葛根素注射液加入250 mL生理盐水中进行静脉滴注，每天1次。两组均治疗10 d。比较两组的临床治疗效果，以及治疗前后的活化部分凝血活酶时间、凝血酶时间、凝血酶原时间和血浆纤维蛋白原，全血黏度低切、血细胞比容、全血黏度高切、血浆黏度和纯音听阈值。结果 观察组的有效率为89.74%，明显高于对照组的71.79%，差异有统计学意义（P<0.05）。两组治疗后的凝血酶时间、活化部分凝血活酶时间以及凝血酶原时间均明显升高，血浆纤维蛋白原明显降低，同组治疗前后比较差异有统计学意义（P<0.05）；且两组间相比差异有统计学意义（P<0.05）。两组治疗后的全血黏度低切、血细胞比容、全血黏度高切及血浆黏度均明显降低，同组治疗前后比较差异有统计学意义（P<0.05）；且观察组明显低于对照组，差异有统计学意义（P<0.05）。两组治疗后的纯音听阈值均明显改善，同组治疗前后比较差异有统计学意义（P<0.05）；且观察组明显优于对照组，差异有统计学意义（P<0.05）。结论 葛根素注射液联合巴曲酶治疗突发性耳聋的临床效果明显优于单独使用巴曲酶，不仅可以有效改善患者的临床症状还可以改善血液流变学状态以及血液高凝状态。     

糖皮质激素治疗突发性耳聋的临床效果观察

目的：研究分析糖皮质激素治疗突发性耳聋的临床效果。方法：选取在我院治疗的突发性耳聋患者80例（2014年5月～2015年5月）。将其动态随机化分2组，研究组和对照组各40例。对照组患者给予非激素常规治疗，研究组患者在常规治疗的基础上给予糖皮质激素进行治疗，对比两组患者突发性耳聋的临床疗效。结果：研究组患者治愈率为27．50％，总有效率为87．50％，与对照组患者对比存在明显差异（P＜0．05）。结论：采用糖皮质激素对突发性耳聋患者进行治疗的效果显著，能有效改善患者听力情况，在临床上可以广泛应用。     

HMGB1和ENA-78在突发性耳聋患者治疗前后的变化

目的:探寻两种炎症介质血清高迁移率蛋白-1(HMGB1)以及中性粒细胞激活肽-78(ENA-78)在特发性突发性聋患者体内随病情变化的不同,及其这两种物质对该病患者的机体影响和所发挥的作用。方法:采用双抗夹心包板、免疫的方法(ELISA)来检测受试者体内中血清HMGB1和ENA-78的含量,受试者包括114例确诊的突发性耳聋患者(分为低度,中度和重度),38例其他疾病对照患者和36例正常健康的成年对照者。并观察这两种物质在患者治疗前后浓度上所产生的不同。结果:患有特发性突发性聋的患者按本文方案治疗后体内的HMGB1和ENA-78含量比治疗前降低显著,且患病程度越重的被测者血清中HMGB1和ENA-78的浓度越大,有正向关系;患有突发性耳聋的受试者两种被测物的含量高于患有其他疾病及健康的对照者,具有统计学意义(P<0.01)。结论:对于患有特发性突发性聋的患者,HMGB1和ENA-78在体内血清中的浓度可以作为诊断和患者患病程度的检测标准参考。     

金纳多对突发性耳聋患者血流动力学的影响

目的:探讨金纳多对突发性耳聋患者血清hs-CRP、HMGB1、ADP、RES及血流动力学的影响。方法:将2009年8月～2012年5月收治的78例突发性耳聋患者随机分为对照组(常规治疗组)和观察组(加用金多纳组),每组各39例,将两组不同严重程度者治疗前及治疗后10d、20d血清hs-CRP、HMGB1、ADP、RES及血流动力学指标进行比较。结果:观察组轻度、中度及重度者治疗后基底动脉血流动力学指标异常率低于对照组,hs-CRP、HMGB1、ADP、RES改善幅度大于对照组,P均<0.05。结论:金纳多可有效改善突发性耳聋者的hs-CRP、HMGB1、ADP、RES及血流动力学。     

Rapidly progressive bilateral postmeningitic deafness in children: Diagnosis and management

ObjectivesTo determine the diagnostic approach to severe or profound bilateral postmeningitic deafness and to propose management guidelines.Material and methodsA retrospective review of five patients (two adolescents and three infants) with rapidly progressive severe bilateral deafness following an episode of meningitis managed between 2004 and 2010.ResultsThe two adolescents presented Neisseria meningitidis meningitis and the three infants presented Streptococcus pneumoniae meningitis. Acquired bilateral deafness was diagnosed by audiometry an average of 68.8 days (range: 9–210) after the episode of meningitis. Behavioural audiological testing, adapted to age and state of health, was performed in all patients. Deafness was confirmed by Auditory Brainstem Response tests. All five patients were assessed by computed tomography (CT) and magnetic resonance imaging (MRI) within ten days. T2-weighted MRI sequences showed endolymph changes in four patients. CT scan demonstrated ossification in only one patient. Bilateral cochlear implant was performed in all patients, with complete electrode array insertion for eight implants and partial insertion for two implants (20 and 21 out of 22 electrodes inserted). Good results were obtained with cochlear implants in four cases.ConclusionsBilateral deafness can occur immediately or several months after bacterial meningitis, regardless of the micro-organism responsible, justifying screening by behavioural audiological testing adapted to age for two years following bacterial meningitis. Auditory Brainstem Response testing can confirm audiometric findings. When severe or profound bilateral deafness is observed, MRI must be performed urgently to detect endolymph inflammation or ossification. Early bilateral cochlear implantation is recommended in the presence of ossification.     

Common genes for non-syndromic deafness are uncommon in sub-Saharan Africa: A report from Nigeria

IntroductionLittle is known about the molecular epidemiology of deafness in sub-Saharan Africa (SSA). Even in Nigeria, the most populous African nation, no genetic studies of deafness have been conducted. This pioneering work aims at investigating the frequencies of gene mutations relatively common in other parts of the world (i.e. those in GJB2, GJB6, and mitochondrial DNA) among subjects from Nigeria with hearing loss (HL) with no evidence of acquired pathology or syndromic findings. In addition, we review the literature on the genetics of deafness in SSA.MethodWe evaluated 81 unrelated deaf probands from the Yoruba tribe residing in Ibadan, a suburban city in Nigeria, for the aetiology of their deafness. Subjects underwent genetic testing if their history was negative for an environmental cause and physical examination did not find evidence of a syndrome. Both exons of GJB2 and mitochondrial DNA flanking the 1555A>G mutations were PCR-amplified followed by Sanger sequencing. GJB6 deletions were screened via quantitative PCR.ResultWe identified 44 probands who had nonsyndromic deafness with no environmental cause. The age at study time ranged between 8 months and 45 years (mean = 24 years) and age at onset was congenital or prelingual (<age 2 years) in 37 (84%) probands and postlingual in 7 (16%) probands. Among these, 35 probands were the only affected members of their families (simplex cases), while there were at least two affected family members in nine cases (multiplex). Molecular analyses did not show a pathogenic variant in any one of the 44 probands studied.ConclusionGJB2, GJB6 and mitochondrial DNA 1555A>G mutations were not found among this initial cohort of the deaf in Nigeria. This makes imperative the search for other genes in the aetiology of HL in this population.     

GJB2 and GJB6 mutations are an infrequent cause of autosomal-recessive nonsyndromic hearing loss in residents of Mexico

ObjectivesMutations in the DFNB1 locus are the most common cause of autosomal-recessive nonsyndromic hearing loss (ARNSHL) worldwide. The aim of this study was to identify the most frequent mutations in patients with ARNSHL who reside in Northeastern Mexico.MethodsWe determined the nucleotide sequence the coding region of GJB2 of 78 patients with ARNSHL. Polymerase chain reaction assays were used to detect the GJB2 IVS1 + 1G > A mutation and deletions within GJB6.ResultsGJB2 mutations were detected in 9.6% of the alleles, and c.35delG was the most frequent. Six other less-frequent mutations were detected, including an extremely rare variant (c.645_648delTAGA), a novel mutation (c.35G > A), and one of possible Mexican origin (c.34G > T). GJB6 deletions and GJB2 IVS1 + 1G > A were not detected.ConclusionsThese data suggest that mutations in the DFNB1 locus are a rare cause of ARNSHL among the population of Northeastern Mexico. This confirms the genetic heterogeneity of this condition and indicates that further research is required to determine the other mechanisms of pathogenesis of ARNSHL in Mexicans.