先天性巨结肠HuD蛋白表达的实验研究

目的 HuD是神经元胚胎发育中生长锥、突起形成延伸及成熟神经元存活所必须的蛋白,其在肠神经系统发育及先天性巨结肠发生中作用机制尚不明确,国内外均未见相关报道。本文探讨HuD蛋白在先天性巨结肠不同部位肠壁组织中的表达,以了解HuD在先天性巨结肠发病中作用机制。方法分别取15例先天性巨结肠患儿手术切除的病变段、移行段、扩张段结肠壁全层及5例人正常结肠组织,采用免疫组织化学、Western免疫印迹分析对不同部位肠壁HuD蛋白表达进行检测,利用图象分析系统及统计软件进行结果分析。结果先天性巨结肠狭窄段粘膜下和肌间抗HuD蛋白抗体染色缺如,移行段显色程度及表达量都明显减少于扩张段和正常对照组（P〈0．01）;狭窄段和移行段的HuD蛋白水平明显少于扩张段和正常段（P〈O．01）。结论HuD在先天性巨结肠病变段粘膜下、肌间神经丛不表达提示HuD蛋白减少可能是使肠神经系统胚胎发育或成熟神经元存活出现障碍而导致先天性肠无神经节细胞的原因之一。     

先天性巨结肠神经肌肉连接免疫组织化学研究

目的采用免疫组织化学方法，对先天性巨结肠神经肌肉连接进行研究，并探讨其与先天性巨结肠发病机制之间的关系。方法应用免疫组化技术对20例先天性巨结肠病变肠段及10例正常结肠组织标本行突触素和神经丝神经肌肉连接标记，光镜下观察其免疫反应表达。结果对照组的结肠突触素和神经细丝的免疫反应呈强阳性表达，先天性巨结肠组扩张肠段突触素和神经细丝的免疫反应呈阳性或弱阳性表达，狭窄段肠壁突触素和神经细丝的免疫反应呈阴性表达。结论先天性巨结肠病变肠段同时缺乏内源性神经支配和外源性神经支配，处于完全失神经支配状态，Cannon定律是先天性巨结肠的病理生理最简单的解释。     

突触素在肠动力性疾病中的免疫表达及意义

目的观察突触素在先天性巨结肠、慢性便秘、先天性肛门闭锁等肠动力性疾病中的免疫表达,探讨突触素的表达对于肠动力性疾病的意义。方法自36例肠动力性疾病患儿中留取活检标本,应用免疫组化方法对突触素显色。结果先天性巨结肠患儿有神经节细胞肠壁平滑肌肌层突触素大量表达,其中环形肌和纵形肌肌层中神经节细胞、神经纤维呈现不同的免疫反应性;非先天性巨结肠患儿有神经节细胞肠壁粘膜肌层突触素大量表达。肠动力性疾病患儿无神经节细胞肠壁均无突触素表达;移行区肠壁仅可见零星神经节细胞,突触素少量表达。慢性便秘患儿镜下可见突触数量明显降低,但在正常范围。先天性肛门闭锁患儿闭锁部位近端肠壁可见神经节细胞及突触的正常分布,肠壁粘膜下层及肌层见少量发育异常的神经节细胞。结论通过对突触的特异性结合,突触素的免疫表达可以间接检验神经节细胞的数量,而肠动力性疾病的本质是神经节细胞的分布异常,因此突触素的表达对于肠动力性疾病的发病机制的探讨及症状描述有重要意义。     

先天性巨结肠Cajal间质细胞的研究

目的　本研究通过观察Cajal间质细胞 (interstitialcellofCajal,ICC)在先天性巨结肠患者狭窄段、移行段、扩张段中的分布情况 ,探讨ICC在先天性巨结肠发病中的作用。方法　收集我院1999～ 2 0 0 2年 2 6例先天性巨结肠患儿标本。短段型 2 4例 ,长段型 2例。于手术中分别选取扩张段 ,移行段及狭窄段肠壁的全层组织。采用SP法 (过氧化物酶标记的链霉卵白素法 )免疫组织化学技术 ,对 2 6例先天性巨结肠的狭窄段、移行段及扩张段标本分别进行c kit免疫组织化学反应 ,观察Ca jal间质细胞分布情况。 结果　发现ICC的密度从扩张段→移行段→狭窄段是逐渐减低的。ICC与肌间神经丛关系密切 ,在扩张段ICC分布在神经丛的周边部和内部 ,且数量相对较多 ,在狭窄段ICC偶见于神经丛的周边部 ,在神经丛内部未见该细胞。光学显微镜下比较同一例患者扩张段和狭窄段神经丛中Cajal间质细胞的数目不同 (t=2 3.0 4 ,P <0 .0 5 ) ,有统计学显著性差异。结论　ICC的分布异常与先天性巨结肠的发生有密切关系。我们推测胚胎基质的某种缺陷不仅损害了神经嵴细胞的移行 ,也影响ICC的分化和成熟。我们可以推论 ,与HD肠壁神经节缺失一样 ,ICC分布异常导致HD病变肠管慢波节律和兴奋传导异常 ,从而引起或加重HD的发病。     

先天性巨结肠肠粘膜紧密连接蛋白分布表达方式的研究

目的探讨紧密连接蛋白在先天性巨结肠不同部位肠粘膜组织内的分布表达方式。方法采用免疫组织化学、Western免疫印迹分析分别对24例先天性巨结肠患儿手术切除的病变段、移行段、扩张段结肠壁粘膜层及10例人正常结肠粘膜的紧密连接蛋白Occludin及ZO-1的分布表达进行检测,利用图像分析系统及统计软件进行结果分析。结果正常结肠粘膜层Occludin及ZO-1沿绒毛下方连续分布;先天性巨结肠狭窄段粘膜层Oc-cludin及ZO-1蛋白数量明显减少、散乱;移行段Occludin显色程度明显少于扩张段和正常对照组(P<0.01),且分布异常,ZO-1蛋白分布异常,显色程度略减少于扩张段和正常对照组;扩张段Occludin及ZO-1蛋白显色程度及分布与正常段相比差异无显著性(P>0.05)。结论先天性巨结肠病变段、移行段紧密连接蛋白分布异常及数量减少,影响肠粘膜上皮屏障的完整性,可能是先天性巨结肠易并发小肠结肠炎的原因之一。     

神经微丝蛋白在先天性巨结肠和巨结肠同源病的表达变化

目的 了解神经微丝蛋白（neurofilament protein，NFP）在先天性巨结肠（Hirschsprung’s disease，HD）和巨结肠同源病（allied Hirsehsprung’s disorder，HAD）肠组织的表达，观察NFP与先天性巨结肠及其同源病的相互关系，进一步探讨两种疾病的发病机制。方法 采用鼠抗人NFP单克隆抗体通过免疫组化法对15例先天性巨结肠，11例巨结肠同源病肠组织NFP的表达进行研究，10例正常结肠组织作对照。结果对照组正常肠段肌间神经丛中有大量NFP阳性纤维和NFP阳性神经细胞，阳性细胞突起少而粗短；HD狭窄段肠管肌间神经丛中未见NFP阳性细胞，但可见大量着色深的NFP阳性纤维；HAD狭窄段肌间神经丛中可见形态各异的NFP阳性细胞，细胞大，且着色深，突起多，丛中只见少量NFP阳性纤维。HD的扩张段和HAD的扩张段分别与正常结肠比较，NFP的表达无统计学意义（P〉0．05）；HD狭窄段分别与HAD狭窄段和正常结肠比较，NFP的表达均有差异（P〈0．01）；HAD狭窄段和正常结肠比较，差异也有显著性意义（P〈0．01）。结论 NFP可能与HD和HAD的发生均有关系，但NFP在HD和HAD的表达有差异。     

先天性巨结肠与巨结肠同源病的Ret蛋白免疫组织化学研究

目的了解Ret蛋白在先天性巨结肠和具结肠同源病肠组织中的表达,并进一步研究Ret蛋白在先天性巨结肠和巨结肠同源病发病中的作用。方法采用鼠抗人Ret单克隆抗体通过免疫组化SABC法对15例先天性巨结肠,11例巨结肠同源病肠组织Ret蛋白的表达进行研究,10例正常结肠组织作对照。结果Ret蛋白在先天性巨结肠和巨结肠同源病的扩张段,对照组均呈现阳性反应（P〉0．05）,在先天性巨结肠狭窄段大多数表现为阴性反应,极少数出现阳性反应,而巨结肠同源病狭窄段可见Ret免疫反应蛋白阳性细胞,而且偶见巨大的阳性细胞;先天性巨结肠狭窄段分别与巨结肠同源病狭窄段和对照组比较均有统计学意义（P〈0．001）。结论Ret蛋白对先天性巨结肠的发生有重要作用,而与巨结肠同源病的发生无明确关系。     

SOX10mRNA在先天性巨结肠肠壁中的表达

目的研究性别决定区Y基因相关高可变区基因10（SRY related high mobilitvgroup—BoX gene10，SOX10）在先天性巨结肠（Hirschsprung’s disease，HD）肠壁中的表达情况，以进一步了解HD在分子基础上的发病机制。方法分别取12例先天性巨结肠病例的手术标本狭窄段、移行段及扩张段，随机取12例非巨结肠手术病例（如结肠造瘘或关瘘手术）作为对照组，提取平滑肌组织总RNA，应用逆转录多聚酶链反应（RT-PCR）扩增目的基因和看家基因片段，观察病变段和正常段SOX10mRNA的表达，并与看家基因（B—actin）在病变段和正常段的表达比较，进行统计学分析。结果SOX10mRNA在HD患儿痉挛段呈低表达，在扩张段及正常对照组呈高表达。痉挛段SOX10mRNA的表达量与移行段、扩张段及正常对照组比较，差异均有统计学意义；而移行段、扩张段及对照组比较，差异无统计学意义。结论HD患儿结肠SOX10mRNA的异常分布显示SOXIO基因是出生后肠神经系统维持正常功能所必需的，SOX10mRNA表达减少可引起肠管痉挛，肠腔狭窄，造成肠功能障碍。     

先天性巨结肠RET基因转录水平的研究

目的 探讨ＲＥＴ基因的表达情况与先天性巨结肠发生的关系。方法 采用ＲＴ－ＰＣＲ技术对１２例先天性巨结肠的狭窄段,移行段及扩张段分别做ＲＥＴ基因的表达,并以Ｇ３ＰＤＨ作内参标,观察ＲＥＴ基因的表达情况。结果 发现ＲＥＴ基因的表达从扩张段→移行段→狭窄段是逐渐减低的。结论 提示ＲＥＴ基因与先天性巨结肠的发生有一定的关系。     

先天性巨结肠粘膜肌和Meissener's神经丛病变

探讨先天性巨结肠粘膜肌有关病变特点、规律及Ｍｅｉｓｓｅｎｅｒ’ｓ神经丛的分布。方法对１８例先天性巨结肠手术切除术标本沿系膜侧纵行、全段、不间断取材、切片,均做ＨＥ、ＶＧ、Ｆｏｏｔ’ｓ网状纤维、弹力纤维的变化,及其Ａｕｅｒｂａｃｈ’ｓ神经丛与Ｍｅｉｓｓｅｎｅｒ’ｓ神经丛的分布与关系。结果先天性巨结肠粘膜肌病变表现为：狭窄段粘膜平滑肌动蛋白升消失,网状纤维、弹力纤维网络状结构变形、塌陷以至消失,其减少     

PERIPHERIN: A Novel Marker for the Immunohistochemical Study of Malformations of the Enteric Nervous System

Peripherin is a 57-kD type III intermediate filament that is a specific marker for peripheral neurons, including enteric ganglion cells (GCs). Hence antibodies to peripherin may be used to demonstrate abnormalities of the enteric nervous system (ENS). Serial longitudinal histologic sections of formalinfixed paraffin-embedded colons from 15 patients were immunostained for peripherin, neuron-specific enolase (NSE), neurofilaments, S-100, and synaptophysin. Ten patients had variable degrees of colonic aganglionosis (Hirschsprung's disease), three were premature infants, and two were controls. Peripherin labeling yielded the highest number of recognizable GCs. Overall, 56%, 78%, and 80% of the peripherin-positive GCs in the myenteric plexus and 55%, 75%, and 73% of the peripherinpositive GCs in the submucosal plexus were identified by staining for neurofilaments, NSE, and S-100, respectively. Intramucosal GCs were detected in 4 of 10 cases of Hirschsprung's disease (HD), none of which had been evident by routine histology. The other neuronal markers were less specific for intramucosal GCs than peripherin, because they also labeled enterochromaffin cells. Peripherin immunohistochemistry also allowed exact quantification of GC density expressed as GCs/mm colon, which is important for the diagnosis of HD-related disorders. In three cases of HD the GC density of the transition zone was markedly elevated compared with more proximal ganglionic bowel segments, consistent with neuronal intestinal dysplasia type B, and two cases of HD showed low GC density within the transition zone. Hence peripherin immunolabeling may prove to be a valuable aid in the diagnosis and classification of congenital malformations of the ENS.     

先天性巨结肠患儿切除肠管肠黏膜ENS干细胞的初步鉴定

目的 我们已经证实p75NTR阳性细胞在HD(Hirschsprung's disease)患儿切除肠管的移形段和扩张段肌间丛及黏膜下丛存在,本研究拟对肠黏膜层进行研究.另外,为了明确Metzger等在肠黏膜活检标本中分离体外培养出的肠黏膜ENS干细胞是胚胎残留还是其他肠黏膜干细胞在诱导分化过程中转化而来,本研究选用了不同时期肠神经干细胞标记物(早期:SOX10和Nestin中晚期:TUJ1;晚期:GFAP),对病理已证实的婴儿组(年龄≤1岁)和幼儿组(年龄＞1岁)HD患儿的切除肠管标本连续切片后进行研究.同时对黏膜层、黏膜下丛及肌间丛的SOX10、Nestin、TUJ1及GFAP强阳性表达率进行综合分析,明确GNCSCs在三层间的存在差异及其与年龄间的关系,以指导临床取材.方法 收集临床诊断及病理确诊的HD患儿手术切除标本15例,分为婴儿组(8例)及幼儿组(7例),长段型(2例)及常见型(13例).沿肠管纵轴各取材一处并将其分为3组:第一组为狭窄段肠管,第二组为移行段肠管,第三组为扩张段肠管.对照组选用切除扩张段肠管的近端肠管,阴性对照应用TBS缓冲液作为一抗.应用S-P法分析四个指标在各标本、各部位的表达情况.结果 SOX10、Nestin和TUJ1在移行段和扩张段黏膜层均有强阳性表达,且在黏膜固有层呈散在分布,但主要位于近黏膜肌层,GFAP在移行段和扩张段黏膜层未见阳性表达.肌间丛SOX10、Nestin、TUJ1和GFAP免疫阳性细胞的强阳性表达率高于黏膜下丛,黏膜下丛强阳性表达率高于黏膜层.婴儿组患儿在扩张段肌间丛SOX10和Nestin强阳性表达率较幼儿组高.婴儿组扩张段黏膜层SOX10和Nestin强阳性表达率较幼儿组高.结论 在HD患儿有神经节段肠管肠黏膜可能存在ENS干细胞或前体细胞,且在肠黏膜固有层呈散在分布,但主要定位于近黏膜肌层.SOX10、Nestin、TUJ1和GFAP在HD患儿肌间丛表达水平较黏膜下丛高,而黏膜下丛表达水平较黏膜层高.婴儿组扩张段黏膜层SOX10和Nestin表达水平可能较幼儿组高,随年龄增长可能逐渐降低.初步判定存在于肠黏膜的ENS干细胞或前体细胞可能来源于肠神经嵴细胞.

Abstract：

Objective To identify the enteric nervous system (ENS) stem cells in intestinal mucosa of the patients with Hirschsprung's disease (HD). Methods Fifteen patients were pathologically diagnosed with Hirschsprung's disease. They underwent surgery to remove the aganglionic intestines.The removed intestines were collected for this study. Of the 15 patients, 8 were infants (age≤1 year)and 7 were toddlers (age＞ 1year). Two were long-segment HD, and 13 were short-segment HD.Three pieces of tissues were collected from the stenotic segment, transitional zone and dilated segment of the removed intestines. The intestines proximate to the dilated segment were selected as controls.Immunohistochemical staining of stem cell markers including SOX10, Nestin, TuJ1 and GFAP was performed to indentify the ENS stem cells in intestinal mucosa. The TBS buffer was used as the negative control of the primary antibody. The S-P method was applied to analyze the expressions of the 4stem cell markers through the intestine. Results The expressions of SOX10, Nestin, and TUJ1 in the mucosa of the transitional zone and dilated segment were strong. And scattered SOX10, Nestin, and TUJ1 positive cells were observed in the lamina propria. But most of the SOX10, Nestin, and TUJ1 positive cells located in mucosa closed to the muscularis mucosa. The expression of GFAP in the mucosa of the transitional zone and dilated segment was negative. The expressions of SOX10, Nestin,TUJ1 and GFAP in myenteric plexus were stronger than those of submucosal plexus (SOX10 expression, infant 50% vs 31.3%, toddler 35. 7% vs 21.4%; Nestin expression, infant 43. 8% vs 37. 5%,toddler 28. 6% vs 14. 2%; TUJ1 expression, infant 37. 5% vs 18. 5%; toddler 28. 6% vs 28. 6%;GFAP expression 25.0 % vs 18. 5 % ; toddler 57. 1% vs 35. 7 % ; P ＜ 0. 05 ). The expressions of SOX10, Nestin and TUJ1 were stronger in submucosal plexus than those in mucosa (SOX10 expression, infant 31.3% vs 25. 0%, toddler 21.4% vs 7. 1% ; Nestin expression, infant 25. 0% vs 18. 8%,toddler 14. 3% vs 14. 3%; TUJ1 expression, infant 18. 5% vs 12. 5 %, toddler 28. 6% vs 7. 1%; P＜0. 05). The expressions of SOX10 and Nestin in myenteric plexus of the dilated segment in infants were stronger than thoset in toddler (SOX10, 75. 0% vs 42. 8% ; Nestin, 62. 5% vs 42. 8%, P＜0. 05). The expressions SOX10 and Nestin in mucosa of the the dilated segment in infants were stronger than those in toddler (SOX10, 37. 5% vs 14. 3%; Nestin, 25. 0% vs 14. 3%, P＜0. 05). Conclusions The ENS stem cells may exist in the mucosa of the ganglionic intestines of HD patients, whichare scattered and mostly located in the mucosa near muscularis mucosa. In HD patients, the expressions of SOX10, Nestin, TUJ1 and GFAP in myenteric plexus are higher than those in submucosal plexus. However, the expressions of SOX10, Nestin, TUJ1 and GFAP in the submucosal plexus are higher than those in the mucous layer. The expressions of SOX10 and Nestin in mucosa of the dilated segment in infants are higher than those in toddlers, and it decreases with age. These observations suggest the ENS stem cells or precursor cells in the gut mucosa may be derived from the gut neural crest cells.     

Histopathological differences between recto-sigmoid Hirschsprung's disease and total colonic aganglionosis

Total colonic aganglionosis (TCA) is a severe form of ultra long Hirschsprung's disease with an incidence of 2 to 14% among all forms of intestinal aganglionosis. C-kit positive interstitial cells of Cajal (ICCs) are pacemaker cells that play a key role in the motility function of the bowel. The aim of this study was to compare the innervation and ICCs distribution in total colonic and recto-sigmoid HD. Full thickness colonic specimens were obtained from four children with TCA, ten with recto-sigmoid HD and four controls. Single immunohistochemistry using peripherin, neuronal nitric oxide synthase (nNOS) and c-kit antibody was performed and analysed in light microscopy. Additionally, whole-mount preparations were stained using anti c-kit immunohistochemistry and NADPH-diaphorase. In the ganglionic bowel of TCA, recto-sigmoid HD and control patients there was a strong nNOS and peripherin immunoreactivity (IR) in ganglia of myenteric and submucous plexus and in thin nerve fibres in the muscle layers. In the TCA there was weak or lack of nNOS IR in the sparse, short nerve trunks of the myenteric and submucous plexuses and muscle layers, whereas nNOS weakly positive nerve trunks were observed in the recto-sigmoid HD bowel. Peripherin IR was markedly reduced in the TCA specimens compared to recto-sigmoid HD. In the TCA specimens there was a lack of ICCs-MY in the smooth muscle layer in all the specimens, whereas in the recto-sigmoid aganglionic bowel ICCs-MY were markedly reduced. Whole-mount preparations showed lack of ICCs-MY and a markedly reduced number of NADPH-positive nerve trunks in TCA. Our findings demonstrate clear histopathological differences between rectosigmoid Hirschsprung's disease and total colonic aganglionosis.     

Developmental changes of the adrenergic network in the myenteric plexus of the porcine small bowel

Knowledge about the foetal development of the normal enteric nervous system (ENS) is crucial for the understanding of congenital and acquired functional abnormalities of the gut. The ENS is the largest and most complex division of the peripheral nervous system and consists of intrinsic and extrinsic components. Although previous studies have described sympathetic innervation of the myenteric plexus, little is known regarding its age-related changes. The aim of this study was to investigate the age-related changes in the sympathetic innervation of the myenteric plexus. Whole mount and paraffin sections of the small bowel specimens from six different age groups (60 and 90 days gestation; newborn; 4 and 12 weeks old; and adult) were stained using tyrosine hydroxylase immunohistochemistry. Specimens were then analysed using fluorescence and laser scanning microscopy in detail. The tyrosine hydroxylase positive nerve fibres were first seen within the myenteric plexus at 90 days of gestation (E90). There was a significant increase in nerve fibres and varicosities observed from E90 to 12 weeks of age and stabilisation thereafter. The degree of varicosities around the ganglia, clearly seen on the whole-mount preparations, was also noted to increase up to 12 weeks of age, after which time there was no general variation noted into adulthood. Our findings show, for the first time, that sympathetic innervation of the myenteric plexus starts in the last quarter of gestation and continues till 12 weeks of age. Segmental sympathetic denervation, following bowel resection and anastomosis, during this developmental period may explain the motility dysfunction seen in newborn infants operated for necrotising enterocolitis, bowel atresia and Hirschsprung’s disease.     

先天性巨结肠c-kit+肠间质细胞分布的免疫组织化学研究

目的：了解先天性巨结肠（HD）肠壁内神经节细胞与肠间质细胞（ICCs）分布的关系。以进一步研究HD的发病机制。方法：采用兔抗人多克隆c-kit抗体，通过免疫组化SABC法观察了58例HD患儿及12例正常儿结、直肠壁内c-kit^ ICCs的分布情况，患儿年龄3个月－10岁，男46例，女12例，短段型HD7例，常见型30例，长段型16例，全结肠型5例。结果：对照组肠肌层内及肌间神经节周围分布有中等量至大量的c-kit^ ICCs，并连接成网络状结构，而在肌间神经节和粘膜下神经内均无c-kit免疫反应性表达，在HD有神经节细胞段肠壁内c-kit^ ICCs的数目和分布与正常对照组无显著差异（P＞0．05），而在HD有神经节细胞段及正常对照组相比，差异有显著性意义（P＜0．01），结论：c-kit^ ICCs的异常分布可能与HD肠动力障碍的发生机制有关。     

How to approach the ENS: various ways to analyse motility disorders in situ and in vitro.

Motility disorders of the human intestine are so variable that they cannot be diagnosed by just one technique. Their aetiology is obviously so varied that they have to be approached with a broad range of technical methods. These reach from the simple haematoxylin-stained section to the isolation of stem or precursor cells. In this study, various methods to investigate the enteric nervous system and its surrounding tissue are demonstrated. While sections from paraffin-embedded material or cryostat sections provide only a two-dimensional perspective of the ENS, the whole-mount method yields three-dimensional perspectives of large areas of the gut wall. The three-dimensional impression can even be enhanced by electron microscopy of the isolated ENS. Dynamical aspects of ENS development can be tackled by in vitro studies. The myenteric plexus can be isolated and cultivated under the influence of the microenvironment (protein extracts). Although the postnatal myenteric plexus is not fully developed, the choice of embryological neuronal cells seems to be more effective for certain approaches. They can be isolated from the embryonic mouse gut and cultivated under the influence of various factors. This method seems to us a valuable tool for the investigation of the aetiology of motility disorders, although only a "complete" approach which considers all available methods will yield at the end a clear understanding which might lead to new therapeutical concepts.     

Klinefelter syndrome as a window on the aetiology of language and communication impairments in children: the neuroligin-neurexin hypothesis

Aim: To compare the phenotype in Klinefelter syndrome (KS) with (i) specific language impairment (SLI) and (ii) XXX and XYY trisomies. Methods: Phenotypes of KS, XXX and XYY were based on data from a systematic review of neurodevelopmental outcomes plus a recent parent survey. Phenotype of SLI was based on a published survey of children attending a special school. Results: There are close similarities between the KS phenotype and SLI. Furthermore, a minority of children with KS have features of autistic spectrum disorder. Similar language and communication problems are seen in the other two sex chromosome trisomies (SCTs), XXX and XYY. Conclusion: We propose the neurexin–neuroligin hypothesis, based on the observation that neuroligin genes, which occur on both X and Y chromosomes, are involved in the same synaptic networks as neurexin genes with common variants that affect risk for SLI and autism. According to our hypothesis, the effect of a triple dose of neuroligin gene product will be particularly detrimental when it occurs in conjunction with specific variants of neurexin genes on other chromosomes. This speculative proposal demonstrates the potential of illuminating the aetiology of common neurodevelopmental disorders by studying children with SCTs.     

神经生长因子受体在先天性巨结肠表达的意义

目的 探讨神经生长因子受体（ＮＧＦＲ）在先天性巨结肠（ＨＤ）中的分布情况及其意义。方法 应用ＮＧＦＲ免疫组化方法对１０例３周￣２岁的ＨＤ患儿及８例对照组患儿结肠进行染色观察。结果 丰富的ＮＧＦＲ染色阳性神经纤维分布于正常结肠环肌层及粘膜下层,少量分布于纵肌层,ＮＧＦＲ染色阳性神经元分布于肌间神经丛及粘膜下神经丛;ＮＧＦＲ染色阳性神经纤维在ＨＤ无肌间神经节细胞肠段肌层及粘膜下层内明显减少或缺如,而肌     

Submucosal plexus of dilatated gut disappears after ligation in chicken embryos: preliminary results.

INTRODUCTION: Dilatation and impaired function of the gut is a condition often seen in newborns with bowel obstruction caused by intestinal atresia. In a previous experimental study in chicken embryos, we established a model to study ultrastructural changes during the development of the enteric nervous system after small bowel ligation. The aim of this study is to investigate the changes of the enteric nervous system (ENS) after gut ligation. METHODS: 56 chicken embryos were investigated. In the operation group fertilized eggs and the allantoic membrane were opened and the small bowel was ligated on embryonal day (ED) 11. The controls were sham-operated. The gut was prepared and harvested for analysis on ED 11, 12, 13, 14, 15, 16, 17 and 18. Silver staining or staining of the specimens for acetylcholinesterase (AchE) was performed. RESULTS: A marked dilatation of the bowel was observed three days after operation (ED 14). The submucosal (PSM) and myenteric plexus (PM) appeared normal at this time, however silver staining showed rarification of the neuronal axonal network between the myenteric and submucosal plexus. Later, on ED 16 an additional rarification of the submucosal plexus was also seen in the operation group using AchE staining, compared to the controls. DISCUSSION: The data suggest that distension of the gut hinders normal development of the ENS in the gut ligation model of chicken embryos. The changes were observed sequentially, starting with rarification of the axonal network between the PM and PSM. Future studies will be required to show whether the changes of the ENS are reversible.     

Mouse-isolated plexus differentiates neural crest precursors into enteric neuroblasts.

Aim of this study was to investigate, for the first time, whether isolated newborn mouse enteric plexus could induce in vitro differentiation of the vagal neural crest-derived cells into enteric neuroblasts. Fragments of the myenteric plexus were isolated from the small intestine of 6-day-old Swiss mice and were collected and stored in DMEM-F12 medium, then cultured on polymerized human fibronectin layer. The vagal portion of the neural tube, isolated from a 9.5-day-old Swiss mouse embryo, was put in the same chamber slides where the isolated myenteric plexus had been cultured for 3 days. The vagal neural crest-derived cells migrated onto the polymerized human fibronectin layer and formed a crown of cells around the neural tube. After 6 days, the cultures were stopped and studied immunohistochemically for anti-NF160 KD, anti-TH, and RetR5 antibodies to analyse the differentiation stage of the cultured cells. Analysis of results included the comparison of two culture groups: Group 1, used as control, in which vagal neural crest-derived cells were put in DMEM-F12, supplemented only with 10 % of FCS; Group 2, in which vagal neural crest-derived cells were put in the same medium as Group 1, with the addition of myenteric plexus fragments isolated from newborn mice to form the co-culture. The following results were obtained: in Group 1 the neural tubes originated a cell population strongly positive for anti-NF160 and anti-TH Ab, but negative for RetR5 Ab. This positivity was found both in the cells adjacent to the neural tube and in those migrating from it distally. The Group 2 originated cells, which after migration were positive for anti-NF160 and for anti-TH antibodies. In addition, in this culture group, the cells which migrated from the neural tube were positive for anti-RetR5 antibody. The co-culture used in this study induces the differentiation of vagal stem cells into enteric neuroblasts, cells TH+ and RetR5+. These cells, after reaching the embryonic intestine, migrate to colonize the hindgut and form the ENS. Therefore this biotechnology seems a good method to obtain in vitro enteric precursors of ENS.