Inhibition of repulsive guidance molecule,RGMa, increases afferent synapse formation with auditory hair cells

The peripheral fibers that extend from auditory neurons to hair cells are sensitive to damage, and replacement of the fibers and their afferent synapse with hair cells would be of therapeutic interest. Here, we show that RGMa, a repulsive guidance molecule previously shown to play a role in the development of the chick visual system, is expressed in the developing, newborn, and mature mouse inner ear. The effect of RGMa on synaptogenesis between afferent neurons and hair cells, from which afferent connections had been removed, was assessed. Contact of neural processes with hair cells and elaboration of postsynaptic densities at sites of the ribbon synapse were increased by treatment with a blocking antibody to RGMa, and pruning of auditory fibers to achieve the mature branching pattern of afferent neurons was accelerated. Inhibition by RGMa could thus explain why auditory neurons have a low capacity to regenerate peripheral processes: postnatal spiral ganglion neurons retain the capacity to send out processes that respond to signals for synapse formation, but expression of RGMa postnatally appears to be detrimental to regeneration of afferent hair cell innervation and antagonizes synaptogenesis. Increased synaptogenesis after inhibition of RGMa suggests that manipulation of guidance or inhibitory factors may provide a route to increase formation of new synapses at deafferented hair cells. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 74: 457–466, 2014     

Studies of morphogenesis at the Department of Embryology, Moscow State University: Towards understanding the dynamic architecture of development

This is a review of studies on morphogenesis carried out at the Department of Embryology, Moscow State University, over the past 30 years. The main direction of studies has been to reveal and describe the properties of self-organizing fields of mechanical stresses in developing embryos.     

Whole Cell Patch Clamp for Investigating the Mechanisms of Infrared Neural Stimulation

It has been demonstrated in recent years that pulsed, infrared laser light can be used to elicit electrical responses in neural tissue, independent of any further modification of the target tissue. Infrared neural stimulation has been reported in a variety of peripheral and sensory neural tissue in vivo, with particular interest shown in stimulation of neurons in the auditory nerve. However, while INS has been shown to work in these settings, the mechanism (or mechanisms) by which infrared light causes neural excitation is currently not well understood. The protocol presented here describes a whole cell patch clamp method designed to facilitate the investigation of infrared neural stimulation in cultured primary auditory neurons. By thoroughly characterizing the response of these cells to infrared laser illumination in vitro under controlled conditions, it may be possible to gain an improved understanding of the fundamental physical and biochemical processes underlying infrared neural stimulation.     

Regulation of spiral growth in planorbid gastropods

Extensive experimentation has been performed on the planorbid Planorbarius metidjensis in order to determine which mechanism allows the snail to coil its shell regularly. Individuals of this species, like all Planorbidae, are permanently active and secrete their shells while crawling on the substrate. Experiments consisted of attaching weights to either side of the shell (which is carried almost vertically) in an umbilical position; these weights cause the shell to fall towards the substrate on the loaded side. It can be demonstrated, qualitatively and quantitatively, that during further growth the shell tube deviated initially (i.e. within the first half whorl after loading) towards the loaded side. In a later stage, when the animal is able to re-balance the shell-load complex by muscular activity, the shell tube gradually deviates away from the loaded side. This behaviour is to be expected if, after loading, secretion of the shell continued with the aperture parallel to the substrate and forming a constant angle with the direction of growth. The main implication is that in normal conditions the living posture largely controls the correct coiling of the shell. Minor experiments made with another planorbid species, Gyraulus laevis , confirm these conclusions. The growth pattern of planorbids requires that the snail has constant information on the orientation of the shell with respect to the substrate. This is permitted by the particular physiological ecology of this group, members of which, unlike terrestrial gastropods, are permanently active.     

Ileo-caecal resection induced pancreatic growth in rats

The effect of ileo-caecal resection on pancreatic growth was studied in rats four weeks after the operation. The results were compared with an identical control group who had undergone laparotomy alone. Pancreatic wet weight in ileo-caecal resectioned rats was 1.4 times greater than that found in control rats. Protein, DNA, RNA contents in the pancreas, pancreatic wet weight per 100 micrograms DNA and RNA/DNA ratio were also found significantly elevated in experimental group as opposed to the control group. Basal plasma levels of cholecystokinin (CCK) and gastrin were measured to delineate the influence of hormonal response on the pancreatic growth in ileo-caecal resected rats and were found not significantly increased after ileo-caecal resection. The data suggest that the enlargement of pancreas in ileo-caecal resected rats may be due to hyperplasia and hypertrophy of pancreatic cells; alternatively, the pancreatic growth may have been influenced by the bile acid deficiency and the reduction or release of an inhibitory factor present in the ileum of rats.     

内镜揭盖术与唇齿沟径路切除术治疗鼻前庭囊肿患者的疗效及对炎性因子的影响

目的:研究内镜揭盖术(ER)与唇齿沟径路切除术(LSPR)治疗鼻前庭囊肿(NVC)患者的临床疗效及对炎性因子的影响。方法:选择2015年7月至2017年6月来我院就诊的NVC患者106例,依据随机数字表法分别纳入ER组(53例)及LSPR组(53例)。ER组行ER治疗,LSPR组行唇齿沟径路切除术。观察两组术中出血量、手术时间、术后创口愈合时间、术后24 h疼痛评分及上皮化时间,两组术前、术后7 d白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)、C-反应蛋白(CRP)水平,两组术后并发症及复发情况。结果:ER组术中出血量、手术时间、术后创口愈合时间、术后24h疼痛评分及上皮化时间等手术指标均低于LSPR组,差异有统计学意义(P0.05);术后7 d,两组IL-6、IL-8、TNF-α及CRP水平均低于治疗前,且ER组低于LSPR组,差异有统计学意义(P0.05);ER组术后并发症发生率7.55%、术后复发率3.77%,均低于LSPR组的22.64%、20.75%,差异均有统计学意义(P0.05)。结论:与LSPR相比较,ER治疗NVC创伤小,恢复快,可有效降低术后炎性因子水平,术后并发症及复发率低,值得临床应用。     

超声引导下Mammotome微创旋切术治疗乳腺良性肿块

目的:研究超声引导下Mammotome微创旋切术对乳腺良性肿块的治疗价值。方法:回顾性分析2014年9月至2016年9月在本院就诊的BI-RADS分级为2~3级的387例乳腺良性肿块患者,运用Mammotome对729处乳腺病灶行微创旋切术,分析术后病理、并发症、随访半年后的治疗结果。结果:387例患者的729处乳腺病灶均获一次性成功切除。病理示均为良性病灶,其中32个合并不典型增生。术后出现局部血肿共11例(2.8%),皮下瘀斑共16例(4.1%),所有患者均未发生感染及气胸等严重并发症。术后6个月18个在病灶原部位发现肿块;手术无残留率为97.5%。结论:应用超声引导下Mammotome微创旋切术治疗乳腺良性肿块临床可行。     

七氟烷与丙泊酚对腹腔镜直肠癌根治术患者认知功能、T淋巴细胞及肝功能的影响

目的:探讨七氟烷与丙泊酚对腹腔镜直肠癌根治术患者认知功能、T淋巴细胞水平及肝功能指标的影响。方法:选择2015年6月-2017年8月期间于我院进行腹腔镜直肠癌根治术的110例患者为研究对象,按随机数字表法分为观察组和对照组,每组患者55例。观察组采用丙泊酚静脉全麻方式进行术前麻醉,对照组采用七氟烷吸入全麻方式进行术前麻醉。观察两组患者不同时间点平均动脉压(MAP)、心率(HR)情况,比较两组患者手术前后认知功能、T淋巴细胞水平、肝功能各项指标及不良反应发生情况。结果:两组患者不同时间点MAP、HR组间比较差异无统计学意义(P0.05)。术后6 h、12 h观察组简易精神状态量表(MMSE)评分低于术前,术后6 h、12 h、24 h对照组MMSE评分低于术前和观察组(P0.05)。术后3d两组患者CD3~+、CD4~+、CD4~+/CD8~+水平均降低,CD8~+水平均升高,且观察组CD3~+、CD4~+、CD4~+/CD8~+水平高于对照组,CD8~+水平低于对照组(P0.05)。术后3 d两组患者谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆红素(TBILI)、直接胆红素(DBILI)水平均升高,但观察组患者各项指标水平低于对照组(P0.05)。观察组不良反应发生率为12.73%,与对照组的7.27%比较差异无统计学意义(P0.05)。结论:七氟烷与丙泊酚在腹腔镜直肠癌根治术中的麻醉效果相当,无严重不良反应发生,但应用丙泊酚进行麻醉对患者术后的认知功能、T淋巴细胞、肝功能指标的影响较小,值得临床推广应用。     

Activation of TRAIL‐DR5 pathway promotes sensorineural degeneration in the inner ear

Tumor necrosis factor (TNF) family cytokines are important mediators of inflammation. Elevated levels of serum TNF‐α are associated with human sensorineural hearing loss via poorly understood mechanisms. We demonstrate, for the first time, expression of TNF‐related apoptosis‐inducing ligand (TRAIL) and its signaling death receptor 5 (DR5) in the murine inner ear and show that exogenous TRAIL can trigger hair cell and neuronal degeneration, which can be partly prevented with DR5‐blocking antibodies.