The growth rate of acoustic neuromas: A report of three cases

Summary Until the present time, only a few CT air-cisternographic studies have been done to define the growth rate of acoustic neuromas. By using this method of study, we were able to observe a slow growth rate fo acoustic neuromas in a 41- and a 50-year-old woman over periods of 6–10 months. In contrast, we were unable to find any increase in tumor size during a period of 22 months in a 70-year-old woman.Dedicated to Prof. Dr. Chl. Beck, Freiburg, on the occasion of his 60th birthdayThis paper was delivered in part at the 55th annual meeting of the German Society for ENT Medicine and Head and Throat Surgery in Bad Reichenhall, 3rd–7th July, 1984     

Acoustic radiation force impulse imaging for non‐invasive assessment of liver fibrosis in chronic hepatitis B

Acoustic radiation force impulse (ARFI) imaging is a novel ultrasound‐based elastography method that is integrated in a conventional ultrasound machine. It might provide an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. While previous studies have shown comparable diagnostic accuracy of ARFI to transient elastography in chronic hepatitis C, the aim of the present prospective multicenter study was to evaluate ARFI for the assessment of liver fibrosis in chronic hepatitis B. ARFI imaging involves the mechanical excitation of tissue using short‐duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear‐wave propagation which is tracked using ultrasonic, correlation‐based methods and recorded in m/s. In the present international prospective study, patients infected with chronic hepatitis B received ARFI imaging, blood tests and if available transient elastography. The results were compared to liver biopsy as reference method analysed by a central pathologist. In 92 of 114 patients, a comparison of ARFI with transient elastography was possible. ARFI imaging and transient elastography correlated significantly with histological fibrosis stage. The diagnostic accuracy expressed as areas under ROC curves for ARFI imaging and transient elastography was 0.75 and 0.83 for the diagnosis of significant fibrosis (F ≥ 2), 0.93 and 0.94 for the diagnosis of severe fibrosis (F ≥ 3), and 0.97 and 0.93 for the diagnosis of liver cirrhosis, respectively. No significant difference was found between ARFI and transient elastography. ARFI imaging is a reliable ultrasound‐based method for the assessment of advanced stages of liver fibrosis in chronic hepatitis B.     

低密度脂蛋白受体基因敲除小鼠主动脉粥样硬化超声生物显微镜血管成像研究

目的 利用超声生物显微镜(UBM)动态观察低密度脂蛋白受体(LDL-R)基因敲除小鼠主动脉粥样硬化过程,通过血管成像技术监测主动脉内中膜厚度(IMT)及斑块变化.方法 16周及24周雄性LDLR基因敲除小鼠各10只为实验组,16周及24周雄性C57BL/6小鼠为对照组,用UBM观察小鼠主动脉根部、升主动脉、主动脉弓和颈总动脉形态结构,测量主动脉弓及颈总动脉内径,并于主动脉根部(定位于主动脉瓣上100 μm处)及颈动脉分叉部测量内中膜厚度(IMT),与相对应血管节段的病理组织学进行对比分析.结果 16周的LDL-R基因敲除小鼠主动脉根部IMT与同龄对照组差异无统计学意义,24周的LDL-R基因敲除小鼠主动脉根部IMT与同龄对照组及16周LDL-R基因敲除小鼠比较差异有统计学意义(P＜0.01).结论 UBM能够动态观察LDL-R基因敲除小鼠主动脉粥样硬化的病理变化.     

原子力声显微镜评价大鼠心肌骨架

目的本研究用原子力声显微镜观察大鼠心肌细胞的细胞骨架,并对声像图进行分析。方法使用原子力显微镜加声激励对在盖玻片上贴壁生长的H9C2大鼠心肌细胞细胞骨架成像。结果使用原子力声显微镜可以完整显示H9C2大鼠心肌细胞的细胞膜、细胞核以及清晰显示网状结构的细胞骨架结构(微丝、微管、中间丝)。结论原子力声显微镜可以很好地显示大鼠心肌细胞表面及亚表面的细胞骨架结构,进而为研究病理状态的心肌细胞打下基础。     

一种便携式医用超声诊断设备声输出参数测量系统的研制

目的:研制一种便于军事计量巡检的便携式声输出参数测量系统。方法:采用水听器作为换能器,通过采集超声信 号在空间声场内一点的声压波形。利用近似公式对声压波形的参数进行运算。得到所关心的超声声输出参数。结果:能 够在误差允许的范围内测量出主要的声输出参数。结论:该方法切实可行,能够改进目前所采用测量方法的缺陷。     

听骨链修复与功能重建的理论与实践

旨在消除或缩小气骨导差的中耳重建技术起自20世纪初,Matte（1901）首先报道的鼓膜一镫骨连接技术（nlyringostapediopexy）被认为具有标志性意义,此后”j现了很多旨在建立鼓膜和内耳淋巴液间联系的方法。直到20世纪50年代,Zollner（1955）和Wullstein（1956）的工作使之成为公认的现代听骨重建技术的奠基者。与之相伴的外科技术以及材料科学的进步,使得中耳重建手术的效果逐步提高。虽可明品改善患者听力水平,但欲获得稳定的远期疗效仍面临许多问题。术后感染、局部粘连、排斥反应以及耳咽管功能障碍等成为影响效果的主要因素。     

Antioxidants Reduce Cellular and Functional Changes Induced by Intense Noise in the Inner Ear and Cochlear Nucleus

The present study marks the first evaluation of combined application of the antioxidant N-acetylcysteine (NAC) and the free radical spin trap reagent, disodium 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07), as a therapeutic approach for noise-induced hearing loss (NIHL). Pharmacokinetic studies and C-14 tracer experiments demonstrated that both compounds achieve high blood levels within 30 min after i.p injection, with sustained levels of radiolabeled cysteine (released from NAC) in the cochlea, brainstem, and auditory cortex for up to 48 h. Rats exposed to 115 dB octave-band noise (10–20 kHz) for 1 h were treated with combined NAC/HPN-07 beginning 1 h after noise exposure and for two consecutive days. Auditory brainstem responses (ABR) showed that treatment substantially reduced the degree of threshold shift across all test frequencies (2–16 kHz), beginning at 24 h after noise exposure and continuing for up to 21 days. Reduced distortion product otoacoustic emission (DPOAE) level shifts were also detected at 7 and 21 days following noise exposure in treated animals. Noise-induced hair cell (HC) loss, which was localized to the basal half of the cochlea, was reduced in treated animals by 85 and 64 % in the outer and inner HC regions, respectively. Treatment also significantly reduced an increase in c-fos-positive neuronal cells in the cochlear nucleus following noise exposure. However, no detectable spiral ganglion neuron loss was observed after noise exposure. The results reported herein demonstrate that the NAC/HPN-07 combination is a promising pharmacological treatment of NIHL that reduces both temporary and permanent threshold shifts after intense noise exposure and acts to protect cochlear sensory cells, and potentially afferent neurites, from the damaging effects of acoustic trauma. In addition, the drugs were shown to reduce aberrant activation of neurons in the central auditory regions of the brain following noise exposure. It is likely that the protective mechanisms are related to preservation of structural components of the cochlea and blocking the activation of immediate early genes in the auditory centers of the brain.     

听力正常儿童 chirp 声与 click 声听性脑干反应特征比较

目的：比较听力正常儿童chirp声与click声听性脑干反应的特征。方法选择97例（194耳）听力正常儿童,分别采用 CE－chirp 和 click 刺激声进行 ABR 检测,比较两种 ABR 波形辨认率,波Ⅲ、V 潜伏期,波 V反应阈及不同刺激声强度下波 V 的振幅及检测时间。结果chirp－ABR 波Ⅰ辨认率（36％）明显低于 click－ABR （100％）,chirp－ABR 与 click－ABR 波 V 反应阈值差异无统计学意义（P＞0．05）,在刺激声强度为80 dB nHL 时, chirp－ABR 波Ⅲ、V 潜伏期比 click－ABR 短,差异有统计学意义（P＜0．05）,且两种刺激声 ABR 波 V 振幅差异无统计学意义（P＞0．05）;在刺激声强度为50 dB nHL 时,chirp－ABR 波 V 振幅较 click－ABR 明显增大,差异有统计学意义（P＜0．05）;在刺激声强度分别为80、50 dB nHL 时,chirp－ABR 波 V 振幅差异无统计学意义（P＞0．05）;chirp－ABR 较 click－ABR 检测时间短,差异有统计学意义（P＜0．05）。结论与 click－ABR 相比,chirp－ABR 的反应幅度高,潜伏期短,检测时间短,用于儿童听力检测具有明显优势。     

Diving into dual functionality: Swim bladder muscles in lionfish for buoyancy and sonic capabilities

Although the primary function of the swim bladder is buoyancy, it is also involved in hearing, and it can be associated with sonic muscles for voluntary sound production. The use of the swim bladder and associated muscles in sound production could be an exaptation since this is not its first function. We however lack models showing that the same muscles can be used in both movement and sound production. In this study, we investigate the functions of the muscles associated with the swim bladder in different Pteroinae (lionfish) species. Our results indicate that Pterois volitans, P. radiata and Dendrochirus zebra are able to produce long low-frequency hums when disturbed. The deliberate movements of the fin spines during sound production suggest that these sounds may serve as aposematic signals. In P. volitans and P. radiata, hums can be punctuated by intermittent louder pulses called knocks. Analysis of sonic features, morphology, electromyography and histology strongly suggest that these sounds are most likely produced by muscles closely associated with the swim bladder. These muscles originate from the neurocranium and insert on the posterior part of the swim bladder. Additionally, cineradiography supports the hypothesis that these same muscles are involved in altering the swim bladder's length and angle, thereby influencing the pitch of the fish body and participating in manoeuvring and locomotion movements. Fast contraction of the muscle should be related to sound production whereas sustained contractions allows modifications in swim bladder shape and body pitch.