1例伴神经性耳聋的Werner综合征患者WRN基因突变研究

目的:检测1例伴神经性耳聋Werner综合征患者的WRN基因突变情况。方法:收集1例伴神经性耳聋Werner综合征患者及其亲属的外周血标本,提取其外周血总RNA进行RT-PCR,将cDNA产物测序;提取患者外周血基因组DNA进行PCR,将DNA产物测序验证突变,以同样方法检测其1例亲属及30例健康对照。结果:患者WRN基因发现4处碱基改变:内含子2967+237 A>G和3309+26C>T、同义突变c.2361 G>T和c.3237 G>A。结论:该例伴神经性耳聋Werner综合征患者存在WRN基因2个内含子SNP和2个已报道cSNPs。     

Interneurons in the tritocerebrum of the crayfish

In isolated head preparations of the freshwater crayfish Orconectes limosus 268 local and projecting interneurons with branches in the tritocerebrum have been penetrated with glass microelectrodes and characterized for their sensory inputs. Using 3 criteria (sensory modality, site of receptors, response type of interneurons), the interneurons found were divided into 16 classes. The interneurons were either unimodal mechanoreceptive (89%) or bimodal (9% responding to mechanical and chemical stimuli, 2% responding to mechanical and visual stimuli). No trimodal interneurons were found. Within each modality the neurons received mostly bilateral input (70% of all interneurons responding to antennal stimulation, 84% of all chemosensitive interneurons). If the input was lateralized it was more often ipsilateral. The types of interneuronal responses evoked by sensory stimulation were: neurons that were exclusively excited (84%), those that were exclusively inhibited (10%), those that were excited or inhibited depending on the modality or laterality of the stimulus (6%), those showing long lasting excitatory aftereffects (3%), and those showing excitation or inhibition upon identical stimulation depending on the state of the neurons while being stimulated (1%). Interneurons that responded to mechanical antennal stimulation responded best either to low (10 Hz) or to high (100 Hz) stimulus frequencies. Six neurons responded best to a certain phase relationship between the movements of both antennal flagellae.     

应用数字编号法提供合格灭菌手术包

目的　用数字编号法能更简单、完善地为医患双方提供合格的无菌手术包。方法　用数字编号法比较无菌手术包内压力蒸气灭菌化学指示卡粘贴法的优缺点 ,将数字编号和灭菌手术包内压力蒸气灭菌化学指示卡合格记录于手术护理记录单上 ,与无菌手术包内压力蒸气灭菌化学指示卡粘贴于手术护理记录单背面作比较。结果　数字编号法弥补了灭菌手术包内压力蒸气灭菌化学指示卡粘贴法的不足 ,使其更方便、适用。结论　无菌手术包数字编号法可为有关护理同仁提供参考     

Distorted Tonotopy Severely Degrades Neural Representations of Connected Speech in Noise following Acoustic Trauma

Listeners with sensorineural hearing loss (SNHL) struggle to understand speech, especially in noise, despite audibility compensation. These real-world suprathreshold deficits are hypothesized to arise from degraded frequency tuning and reduced temporal-coding precision; however, peripheral neurophysiological studies testing these hypotheses have been largely limited to in-quiet artificial vowels. Here, we measured single auditory-nerve-fiber responses to a connected speech sentence in noise from anesthetized male chinchillas with normal hearing (NH) or noise-induced hearing loss (NIHL). Our results demonstrated that temporal precision was not degraded following acoustic trauma, and furthermore that sharpness of cochlear frequency tuning was not the major factor affecting impaired peripheral coding of connected speech in noise. Rather, the loss of cochlear tonotopy, a hallmark of NH, contributed the most to both consonant-coding and vowel-coding degradations. Because distorted tonotopy varies in degree across etiologies (e.g., noise exposure, age), these results have important implications for understanding and treating individual differences in speech perception for people suffering from SNHL.SIGNIFICANCE STATEMENT Difficulty understanding speech in noise is the primary complaint in audiology clinics and can leave people with sensorineural hearing loss (SNHL) suffering from communication difficulties that affect their professional, social, and family lives, as well as their mental health. We measured single-neuron responses from a preclinical SNHL animal model to characterize salient neural-coding deficits for naturally spoken speech in noise. We found the major mechanism affecting neural coding was not a commonly assumed factor, but rather a disruption of tonotopicity, the systematic mapping of acoustic frequency to cochlear place that is a hallmark of normal hearing. Because the degree of distorted tonotopy varies across hearing-loss etiologies, these results have important implications for precision audiology approaches to diagnosis and treatment of SNHL.     

基于提升小波变换和SPIHT的医学图像编码算法

目的:探讨一种基于提升小波变换和多级树集合分裂算法(set partitioning in hierarchical trees,SPIHT)的医学图像编码算法。方法:针对传统小波浮点数运算,计算量大的缺点,采用提升格式小波,结合多级树集合分裂算法和算术编码,实现对医学图像的编码。结果:在获得较高压缩比的情况下,能保证医学图像的重建质量,满足医学图像数据的存储和传输的需要。结论:仿真结果表明在相同压缩比的情况下,重建图像的峰值信噪比有明显提高,获得了较好的压缩效果。     

Directional asymmetry in smooth ocular tracking in the presence of visual background in young and adult primates

The smooth pursuit system moves the eyes in space accurately while compensating for visual inputs from the moving background and/or vestibular inputs during head movements. To understand the mechanisms underlying such interactions, we examined the influence of a stationary textured visual background on smooth pursuit tracking and compared the results in young and adult humans and monkeys. Six humans (three children, three adults) and six macaque monkeys (five young, one adult) were used. Human eye movements were recorded using infrared oculography and evoked by a sinusoidally moving target presented on a computer monitor. Scleral search coils were used for monkeys while they tracked a target presented on a tangent screen. The target moved in a sinusoidal or trapezoidal fashion with or without whole body rotation in the same plane. Two kinds of backgrounds, homogeneous and stationary textured, were used. Eye velocity gains (eye velocity/target velocity) were calculated in each condition to compare the influence of the textured background. Children showed asymmetric eye movements during vertical pursuit across the textured (but not the homogeneous) background; upward pursuit was severely impaired, and consisted mostly of catch-up saccades. In contrast, adults showed no asymmetry during pursuit across the different backgrounds. Monkeys behaved similarly; only slight effects were observed with the textured background in a mature monkey, whereas upward pursuit was severely impaired in young monkeys. In addition, VOR cancellation was severely impaired during upward eye and head movements, resulting in residual downward VOR in young monkeys. From these results, we conclude that the directional asymmetry observed in young primates may reflect a different neural organization of the vertical, particularly upward, pursuit system in the face of conflicting visual and vestibular inputs that can be associated with pursuit eye movements. Apparently, proper compensation matures later. Electronic Publication