子宫颈低级别鳞状上皮内病变与HR-HPV的关系

目的探讨高危型人乳头状瘤病毒(high risk human papillomavirus,HR-HPV)在子宫颈低级别鳞状上皮内病变(low-grade squamous intraepithelial lesion,LSIL)中的分布特点及感染方式,并分析其在LSIL中的作用。方法应用实时荧光定量PCR和HPV原位杂交技术对328例诊断结果为168例LSIL、160例高级别鳞状上皮内病变(high-grade squamous intraepithelial lesions,HSIL)的子宫颈组织蜡块进行HPV分型检测。结果 HE染色结果显示,LSIL的病变细胞集中在子宫颈鳞状上皮表层,HSIL的病变细胞主要集中在上皮下层。168例LSIL患者中HR-HPV阳性率95.2%;LSIL、HSIL中HPV 16、18阳性率分别为26.2%、57.5%,其他型HR-HPV(不包括HPV 16、18)的阳性率分别为80.9%、55.0%,差异均有统计学意义(P0.001)。在原位杂交检测组中,HR-HPV的阳性率为70.2%,HR-HPV阳性LSIL中,棕黄色阳性细胞位于子宫颈鳞状上皮表层、中层,基底层未见阳性细胞。结论 HR-HPV感染与LSIL的发生、发展密切相关,尤其是其他型HR-HPV(不包括HPV 16、18);LSIL患者中HR-HPV的感染开始于子宫颈鳞状上皮表层。     

HPV DNA、E6/E7 mRNA在各子宫颈病变及子宫颈鳞状细胞癌中的表达

目的 探讨HPV DNA和E6/E7 mRNA在各子宫颈病变及子宫颈鳞状细胞癌(cervical squamous cell carcinoma,CSCC)中的表达,并分析其与CSCC发生、发展的相关性。方法 应用PCR-反向杂交法和支链DNA技术对210例低级别鳞状上皮内病变(low-grade squamous intraepithelial lesion,LSIL)、200例高级别鳞状上皮内病变(high-grade squamous intraepithelial lesion,HSIL)及240例CSCC进行HPV DNA及E6/E7 mRNA的检测。结果 HSIL、CSCC中,HPV DNA百分率分别为100.00%、89.58%,呈递减趋势(P0.001);E6/E7 mRNA百分率分别为52.50%、95.83%,呈递增趋势(P0.001);HPV DNA+/mRNA+的百分率分别为52.50%、87.50%,呈递增趋势(P0.001);HPV DNA-/mRNA-的百分率分别为0、6.25%,呈递增趋势(P0.001)。LSIL、HSIL中,HPV DNA百分率均大于E6/E7 mRNA百分率,差异有统计学意义(P0.001);而CSCC中HPV DNA百分率均小于E6/E7 mRNA百分率,差异有统计学意义(P=0.008)。结论 HPV DNA在LSIL、HSIL中的表达较E6/E7 mRNA高;CSCC中HPV DNA表达较E6/E7 mRNA低,因此HPV DNA标志物可能与CSCC的发生过程关系较为紧密;E6/E7 mRNA标志物可能与CSCC的发展相关性更高。     

HPV E6/E7 mRNA联合HPV L1衣壳蛋白在子宫颈癌前病变诊断中的价值

目的探讨HPV E6/E7 mRNA联合HPV L1衣壳蛋白检测在子宫颈癌前病变诊断中的价值。方法采用分支链DNA信号放大技术检测156例子宫颈活检不同病变组织中HPV E6/E7 mRNA的表达,并应用免疫组化En Vision法检测HPV L1衣壳蛋白的表达。结果与正常组织相比,子宫颈低级别上皮内病变(low-grade squamous intraepithelial lesion,LSIL)、子宫颈高级别上皮内病变(high-grade squamous intraepithelial lesion,HSIL)和子宫颈鳞癌组织中HPV E6/E7mRNA的阳性率增高(P 0. 05),且HSIL和子宫颈癌中HPV E6/E7 mRNA的阳性率高于LSIL(P 0. 05),但HSIL和子宫颈癌组织中HPV E6/E7 mRNA的阳性率差异无显著性(P 0. 05); HPV L1衣壳蛋白在LSIL中的阳性率明显高于HSIL(P 0. 05)。结论通过对子宫颈不同病变标本进行HPV E6/E7 mRNA和HPV L1衣壳蛋白联合检测,了解不同病变子宫颈组织中HPV E6/E7 mRNA和HPV L1衣壳蛋白的表达趋势,可预测子宫颈上皮内病变的发展趋势,指导临床医师进行合理治疗。     

应用时间分辨法检测石蜡包埋子宫颈组织p16~(INK4a)蛋白

目的探讨时间荧光分辨法(time-resolved fluoroimmunoassay,TRFIA)检测子宫颈组织中p16~(INK4a)蛋白的表达。方法选取子宫颈组织病理学小活检标本126例,采用免疫组化EnVision两步法及TRFIA法检测石蜡包埋组织中p16~(INK4a)蛋白。结果126例标本中,未见上皮内病变细胞及恶性细胞20例、低级别鳞状上皮内病变(low-grade squamous intraepithelial lesions,LSIL)24例、高级别鳞状上皮内病变(high-grade squamous intraepithelial lesions,HSIL)53例、子宫颈鳞状细胞癌(squamous cell carcinoma,SCC)29例。免疫组化检测未见上皮内病变细胞及恶性细胞组、LSIL组、HSIL组、SCC组中p16~(INK4a)蛋白阳性病例分别为1、19、53、28例,TRFIA检测p16~(INK4a)蛋白阳性病例分别为3、17、50、27例。LSIL、HSIL及SCC组中,TRFIA检测p16~(INK4a)蛋白阳性的病例经免疫组化结果均为阳性。TRFIA检测p16~(INK4a)蛋白在未见上皮内病变细胞及恶性细胞组、LSIL、HSIL及SCC组的阳性率分别为15.00%、70.83%、93.90%,差异有显著性(P0.01)。结论 TRFIA适合于检测p16~(INK4a)蛋白,且对检测条件要求低,有利于临床工作中不同机构大规模检测。     

子宫颈鳞状上皮内病变感染高危型人乳头瘤病毒型别分析

目的探讨子宫颈鳞状上皮内病变感染高危型人乳头瘤病毒(high-risk human papilloma virus,HR-HPV)型别分布规律,为临床治疗提供指导。方法选取130例行阴道镜活检并经病理诊断为子宫颈鳞状上皮内病变患者作为分析对象,其中子宫颈上皮内病变(cervical intraepithelial neoplasia,CIN)Ⅰ～Ⅲ级118例和子宫颈鳞状细胞癌(squmaous cell carcinoma,SCC) 12例,采用HR-HPV分型核酸测定试剂盒对患者的子宫颈脱落细胞进行分型检测,观察不同年龄段和不同级别子宫颈鳞状上皮内病变感染HR-HPV型别。结果130例子宫颈鳞状上皮内病变HR-HPV单一型感染率明显高于多重型,HR-HPV中HPV 16、58、52感染率较高,单一型HPV 16阳性检出率SCC组明显高于CIN组(P 0. 05)。HR-HPV感染各年龄段中,46～55岁组感染率最高。结论子宫颈鳞状上皮内病变以单一型HR-HPV感染为主,单一型HPV 16感染与子宫颈SCC的发生密切相关,临床需将46～55岁的患者作为重点关注对象。     

子宫颈鳞状上皮内病变中BAG-1、MCM2表达及其与p16、HR-HPV的关系

目的检测子宫颈鳞状上皮内病变(squamous intraepithelial lesion, SIL)组织中BAG-1、MCM2及p16蛋白的表达,探讨其与SIL进展程度、p16表达及高危型人乳头瘤病毒(high-risk human papillomavirus, HR-HPV)感染的相关性。方法采用免疫组化EnVision两步法检测36例正常子宫颈/慢性子宫颈炎、77例低度鳞状上皮内病变(low-grade squamous intraepithelial lesion, LSIL)、69例高度鳞状上皮内病变(high-grade squamous intraepithelial lesion, HSIL)组织中BAG-1、MCM2及p16蛋白的表达,并用PCR反向点杂交法对所有样本行HPV基因分型检测。结果 BAG-1、MCM2及p16蛋白的阳性率在正常子宫颈/慢性子宫颈炎组分别为5.6%(2/36)、2.8%(1/36)及0(0/36),在LSIL组分别为40.3%(31/77)、50.6%(39/77)及27.3%(21/77),在HSIL组分别为85.5%(59/69)、91.3%(63/69)及88.4%(61/69),HR-HPV感染率在三组中分别为25%(9/36)、63.6%(49/77)及92.8%(64/69),BAG-1、MCM2、p16阳性率及HR-HPV感染率均随SIL病变程度上升而增高(P均0.05)。不管在LSIL组还是HSIL组,BAG-1、MCM2表达与p16表达、HR-HPV感染均呈正相关(P均0.05)。结论 BAG-1及MCM2表达与SIL病变程度、p16表达及HR-HPV感染状态呈正相关,它们可能参与了子宫颈SIL的发生、发展过程。     

The relationship between the HR-HPV load and cervical lesions in Chaozhou area

目的 探讨高危型人乳头瘤病毒(high risk human papillomavirus,HR-HPV)载量与宫颈病变级别之间的关系.方法 采用RT-PCR对农村35～60岁女性进行HR-HPV DNA定量检测并记录CT值,2 731例阳性者再进行核酸分子快速导流杂交分型技术(HybriMax)和液基薄层细胞学(thinprep liquid-based cytologic test,LCT)检查;对低级别鳞状上皮内病变(low grade squamous intraepithelial lesion,LSIL)及以上病变行阴道镜下组织病理学活检.根据LCT及病理活检结果按病变级别分成5组:无上皮内瘤变或恶性病变(non-squamous intraepithelial lesion or neoplasia,NILM)、未明确诊断意义的不典型鳞状上皮细胞(atypical squamous cells of undetermined significance,ASCUS)、LSIL、高级别鳞状上皮内病变(high grade squamous intraepithelial lesion,HSIL)和鳞状细胞癌(squamous cell cacinoma,SCC).在同级别宫颈病变中,按照HPV感染的类型分为4组:HPV52、HPV16、HPV58和多重HPV感染.采用方差分析的方法对各组平均CT值进行统计分析.结果 随宫颈病变级别的升高,CT均值降低,5组CT均值间差异均具有显著性(P＜0.05).在同级别宫颈病变中,NILM组HPV58和多重HPV差异有显著性(P＜0.05),ASCUS组HPV16和多重HPV差异有显著性,其余病变级别各HPV感染组间差异均无显著性(P＞0.05).结论 HR-HPV载量与宫颈病变级别呈正相关,高HR-HPV载量是影响宫颈病变级别的危险因素.     

人乳头瘤病毒L1壳蛋白在子宫颈活检组织中的表达及意义

目的探讨人乳头瘤病毒(human papilloma virus, HPV)L1壳蛋白在HPV阳性子宫颈活检组织中的表达与子宫颈鳞状上皮内病变(squamous intraepithelial lesion, SIL)程度的相关性及其应用价值。方法收集2017年1～9月上海市第一妇婴保健院因HPV阳性行子宫颈活检患者966例,以非同位素标记核酸分子杂交技术和免疫组化技术为基础行HPV L1壳蛋白检测。结果 966例中HPV L1壳蛋白的总阳性率为14.8%(143/966),其中慢性子宫颈炎、低级别鳞状上皮内病变(low grade squamous intraepithelial lesion, LSIL)、高级别鳞状上皮内病变(high grade squamous intraepithelial lesion, HSIL)和子宫颈浸润性鳞状细胞癌中HPV L1壳蛋白的阳性率分别为0.2%(1/513)、37.9%(121/319)、15.9%(21/132)和0(0/2)。LSIL中HPV L1壳蛋白率高于慢性子宫颈炎、HSIL和子宫颈浸润性鳞状细胞癌。结论 HPV L1壳蛋白在子宫颈活检组织中的表达与宫颈鳞状上皮病变程度呈负相关性。HPV L1在帮助了解子宫颈鳞状上皮病变程度,预测子宫颈鳞状上皮病变的发展趋势、转归、预后及选择临床处理方案中有一定参考价值。     

潮州地区高危型HR-HPV感染与子宫颈病变的关系

目的 探讨潮州地区高危型人乳头瘤病毒(HR-HPV)感染与子宫颈病变的关系.方法 采用实时荧光定量PCR技术对潮州农村35～60周岁的妇女进行HR-HPV检测,对HR-HPV阳性妇女进行核酸分子快速导流杂交分型技术(HybriMax)和液基薄层细胞学(LCT)检查,对低级别鳞状上皮内病变(low grade squamous intraepithelial lesions,LSIL)及以上患者行阴道镜下组织病理学活检确诊.结果 潮州地区妇女HR-HPV感染率为8.25%(4 080/49 458).发现15种HR-HPV,感染率最高的型别是HPV52,其次为HPV16、58、68、33和18型.HPV16、HPV59和混合型感染者子宫颈病变较严重,与其他型别感染者子宫颈病变程度差异有显著性(P<0.05).结论 潮州地区人群感染HR-HPV优势型别为HPV52,HR-HPV不同型别与子宫颈病变严重程度密切相关.     

潮州地区高危型人乳头瘤病毒载量与宫颈病变的关系

目的探讨高危型人乳头瘤病毒(high risk human papillomavirus,HR-HPV)载量与宫颈病变级别之间的关系。方法采用RT-PCR对农村35～60岁女性进行HR-HPV DNA定量检测并记录CT值,2 731例阳性者再进行核酸分子快速导流杂交分型技术(HybriMax)和液基薄层细胞学(thinprep liquid-based cytologic test,LCT)检查;对低级别鳞状上皮内病变(low grade squa-mous intraepithelial lesion,LSIL)及以上病变行阴道镜下组织病理学活检。根据LCT及病理活检结果按病变级别分成5组:无上皮内瘤变或恶性病变(non-squamous intraepithelial lesion or neoplasia,NILM)、未明确诊断意义的不典型鳞状上皮细胞(atypi-cal squamous cells of undetermined significance,ASCUS)、LSIL、高级别鳞状上皮内病变(high grade squamous intraepithelial lesion,HSIL)和鳞状细胞癌(squamous cell cacinoma,SCC)。在同级别宫颈病变中,按照HPV感染的类型分为4组:HPV52、HPV16、HPV58和多重HPV感染。采用方差分析的方法对各组平均CT值进行统计分析。结果随宫颈病变级别的升高,CT均值降低,5组CT均值间差异均具有显著性(P<0.05)。在同级别宫颈病变中,NILM组HPV58和多重HPV差异有显著性(P<0.05),ASCUS组HPV16和多重HPV差异有显著性,其余病变级别各HPV感染组间差异均无显著性(P>0.05)。结论 HR-HPV载量与宫颈病变级别呈正相关,高HR-HPV载量是影响宫颈病变级别的危险因素。     

Proteins of the PIAS family enhance the sumoylation of the papillomavirus E1 protein

Sumoylation of the papillomavirus (PV) origin binding helicase E1 protein is critical for its function. Consequently, factors modulating the sumoylation of E1 could ultimately alter the outcome of a papillomavirus infection. We investigated the role played by phosphorylation and two known SUMO E3 ligases, RanBP2 and PIAS proteins, on the sumoylation of E1. E1 sumoylation was unaffected by phosphorylation as both wild-type and pseudo-phosphorylation mutants of BPV E1 exhibited similar sumoylation profiles. RanBP2 bound to BPV E1, but not to HPV11 E1, and lacked sumoylation enhancing activity for either E1. In contrast, proteins of the PIAS family (except PIASy) bound to both BPV and HPV11 E1 and stimulated their sumoylation. The structural integrity of the RING finger domain of the PIAS proteins was required for their E3 SUMO ligase activity on PV E1 sumoylation but was dispensable for their PV E1 binding activity. Miz1, the PIAS protein exerting the strongest E1 sumoylation enhancing activity, favored SUMO1 versus SUMO2 as the modifier and was shown to be transcribed in a keratinocyte cell line. This study indicates PIAS proteins as possible modulators of PV E1 sumoylation during papillomavirus infections.     

河南省人民医院门诊患者戊型病毒性肝炎的阳性率调查

目的 通过检测部分门诊病例血清的戊型肝炎病毒标志物（HEV IgG）,简要描述本地区的戊型病毒性肝炎的感染水平.方法 收集河南省人民医院内科门诊病例血清415份,应用万泰公司的戊型病毒性肝炎诊断试剂盒进行ELISA检测,检测结果进行统计学分析,对不同分组进行x2检验.结果 415例门诊病例的HEV阳性率为21.93％,在性别间、年龄分组间,差异有统计学意义,而在城乡间的差别无统计学意义.结论 我市的戊型病毒性肝炎阳性率处于全国HEV感染率的平均水平,成人的HEV阳性率显著性高于青少年.在低年龄阶段进行有效的疫苗接种,可以控制戊型病毒性肝炎在我省的流行.     

Binocular interaction in the fetal cat regulates the size of the ganglion cell population

During fetal development of the cat's visual system there is a marked overproliferation of optic nerve axons. In utero binocular interaction contributes to the severity of fiber loss since removal of an eye during gestation attenuates axon loss in the remaining optic nerve. The purpose of the present study was to determine whether this reduced loss of optic nerve fibers is due to a failure of retraction by supernumerary axon branches or to a reduction in ganglion cell death. To resolve this issue, we compared the number of ganglion cells and optic nerve fibers in adult cats which had one eye removed at known gestational ages. Retinal ganglion cells were backfilled with horseradish peroxidase and counts were made from retinal wholemounts. The axon complement was assessed with an electron microscopic assay. In the retinas of a normal cat we estimated 151,000 and 152,000 ganglion cells. The optic nerves of two other normal cats contained approximately 158,000 and 159,000 axons. In comparison, an animal enucleated on embryonic day 42 had 180,000 ganglion cells and 178,000 optic nerve fibers, while in an animal enucleated on embryonic day 51 the corresponding estimates were 182,000 and 190,000. The close agreement between cell and fiber counts indicates that axonal bifurcation does not contribute appreciably to the axon surplus in the optic nerve of prenatally enucleated cats. These results demonstrate that prenatal binocular interaction regulates the size of the mature retinal ganglion cell population.     

The stability of the human papillomavirus E6 oncoprotein is E6AP dependent

Human papillomavirus (HPV) E6 oncoproteins target numerous cellular proteins for ubiquitin-mediated degradation. In the case of p53 this is mediated by the E6AP ubiquitin ligase. However, there are conflicting reports concerning how central E6AP is to the global function of the HPV-16 and HPV-18 E6 oncoproteins. To investigate this further we have analysed the effects of E6AP removal upon the stability of endogenously expressed E6 protein. We show that when E6AP is silenced in HPV-positive cells, E6 protein levels are dramatically decreased in a proteasome-dependent manner. Further, we show that when E6AP is depleted in HeLa cells, E6 has a greatly decreased half-life. In addition, overexpression of E6AP stabilises ectopically expressed HPV-16 and HPV-18 E6 in a manner that is independent of its ubiquitin ligase activity. These results demonstrate that the stability of HPV E6 is critically dependent upon the presence of E6AP.     

静磁场作用下大鼠牙槽骨中前列腺素E2变化的研究

目的：通过对大鼠在静磁场和非磁场作用下其牙槽骨的内源性前列腺素Ｅ２随时间变化的对比研究,了解在静磁场作用下,大鼠牙槽骨中前列腺素Ｅ２含量的时间变化性。方法：放射免疫法检测２０只加静磁场、２０只加非磁场和４只空白对照的大鼠牙槽骨中前列腺素Ｅ２的含量,探讨静磁场对大鼠牙槽骨的内源性前列腺素Ｅ２的变化的影响。结果：未受力时,大鼠的牙槽骨内即存在一定数量的前裂腺素Ｅ２。在静磁场作用下,牙槽骨的内源性前列腺     

The growth of cochlear fibers and the formation of their synaptic endings in the avian inner ear: a study with the electron microscope

The developmental sequence of nerve-epithelial cell contacts, leading up to the formation of the mature receptoneuronal synapse, has been studied in the basilar papilla of chick embryos with electron microscopy. The receptor epithelium before innervation, on embryonic days 3-4, consists of a homogeneous population of primitive cells; hair cells and supporting cells cannot be distinguished. During innervation of the epithelium (embryonic days 5-7), the invading peripheral fibers of cochlear ganglion cells penetrate the basal lamina and form nerve-epithelial attachments with the epithelial cell bases. Once within the epithelium some fibers turn and spread in the transverse dimension across the basilar papilla through channels formed between the basal epithelial processes. Subsequently, nerve-epithelial attachments are observed more superficially within the epithelium. Hair cells and supporting cells differentiate during early synaptogenesis (embryonic days 8-9). Receptoneural synapses, possibly derived from the nerve-epithelial attachments formed during the innervation stage, are first seen during this period. They are characterized by symmetrical or asymmetrical membrane densities, separated by a cleft containing a dense material. At many of these junctions synaptic bodies, as well as dense-cored and coated vesicles, gather in the hair cells. During mid-synaptogenesis (embryonic days 11-13) the hair cells proliferate synaptic bodies, many of which are not located at receptoneural junctions. The preterminal portions of the sensory endings form large swellings, containing flocculent material, endoplasmic reticulum and vesicles. Late in synaptogenesis (embryonic days 15-17) the swellings disappear, while synaptic endings are transformed to foot-shaped terminals. In the hair cells, synaptic bodies not associated with junctions disappear. Efferent synapses are first seen during this period. This sequence of ultrastructural changes, which the developing sensory nerve endings and their target cells undergo in parallel, can be correlated with observations of Golgi preparations from a companion study. These correlations suggest that the innervation of the cochlea involves the following developmental processes. Initially the peripheral fibers of the ganglion cells grow directly toward the otocyst in fascicles. Having reached the base of the primitive receptor epithelium, the axonal endings, including some with growth cones, encounter a barrier in the basal lamina. When they enter some of the fibers attach to the basal end-feet of the primitive epithelial cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

Prevalence of specific antibody to hepatitis E virus in the general population of the community of Madrid, Spain

Hepatitis E virus (HEV) is an infectious agent causing hepatitis among humans. Although hepatitis E has been reported from many European countries, its incidence in Europe is largely unknown, and the prevalence of the HEV infection is also unknown for most countries of the region. Antibody to HEV (anti-HEV) was tested on 2,305 serum samples from the general population of the Community of Madrid (Spain) collected in the year 2008 among people aged 2-60 years. Total anti-HEV was tested by enzyme-immunoassay (EIA), and reactive samples were retested separately for anti-HEV IgG and IgM by recombinant immunoblot test (RIBT). Fifty samples (2.17%) displayed reactivity for total anti-HEV after EIA testing, and anti-HEV IgG was confirmed by RIBT in 25 (1.08%). The frequency of RIBT-confirmed anti-HEV ranged from 0.97% among the youngest to 3.61% among the oldest, and displayed a statistically significant trend to increasing with age. The rate of RIBT confirmation was also significantly higher among the individuals aged above 20 years old than among those younger of 21 years. HEV infection would be less frequent in the Community of Madrid than in Catalonia or the United Kingdom, and contact with HEV would be very uncommon among children and adolescents of the region. Confirmation of EIA-reactive samples by RIBT reduced the final numbers of anti-HEV testing as much as 50%, and some findings of this study suggest that such testing protocol would reflect better the real prevalence of anti-HEV in settings of low endemicity than the single testing by EIA.     

人工心脏研究发展态势文献计量分析

目的揭示人工心脏研究论文总体发展趋势,为人工心脏研究提供借鉴。方法利用科学引文索引(SCI-E)的分析功能、文献信息统计方法及MicrosoftExcel作为数据分析的基本方法,进行了文献的数据挖掘和信息分析工作。结果从分析数据得到人工心脏的研究呈上升趋势,美国、德国和日本等国的研究引领世界。结论中国的人工心脏研究已取得了卓有成效的发展,尚需加大资金的投入。     

Trophic interactions between the cochleovestibular ganglion of the chick embryo and its synaptic targets in culture

The effect of the availability of synaptic targets on neuronal survival was tested by explanting the cochleovestibular ganglion from embryonic day 3-1/2 chick embryos and maintaining it in the presence or absence of appropriate synaptic target tissues for 14 days in culture. The targets were the inner ear, peripherally, and the myelencephalon, centrally. Light and electron microscopic observations showed that the ganglion cells in the explants with targets present had generally achieved a degree of differentiation comparable to that of their counterparts in embryonic day 14 embryos. The variety of cell types seen in the normal embryonic day 14 ganglia was also evident in vitro. In ganglia explanted without peripheral or central targets, few neurons survived. Ganglia explanted with either peripheral or central target intact showed considerably better survival than those explanted without any target. Ganglia explanted with only the peripheral target (the inner ear) survived equally as well as those with both central and peripheral targets. Ganglia cultured with the central target (myelencephalon) did not survive as well as those with peripheral targets. The effect of the peripheral target on the ganglion was less clear-cut when ganglia were first dissected from their targets and then recombined in culture. However, the results of such experiments in which nerve fascicles were traced in serial sections from ganglia to target areas, suggest that the actual innervation of target cells, as well as proximity of ganglia to target tissues, could influence neuronal survival. Establishment of innervation appeared to be selective, in that the closest available target area was not always the one contacted by the ganglionic fibers. The present findings are consistent with a role of neuron-target cell interactions in supporting neuronal survival in the cochleovestibular ganglion of the chick embryo. Both the central and the peripheral targets are implicated in trophic interactions with the sensory neurons.