神经干细胞移植治疗结肠去神经节小鼠

目的 观察神经干细胞在去神经节小鼠结肠壁内的存活分化,探讨神经干细胞移植治疗结肠无神经节细胞症的可行性.方法 0.5%苯扎氯铵(BAC)处理8周龄昆明小鼠结肠浆膜层选择性去除结肠肇神经节制作巨结肠模型,原代培养新生小鼠大脑皮质来源神经干细胞,Hoechsd3342标记传代纯化后神经干细胞.运用微量注射器将标记后的神经干细胞移植入模型鼠病变肠段,分别于术后1、2、3、4周行大体观察,苏木素-伊红(HE)染色,免疫组织荧光检测小鼠生物学特性和神经干细胞存活分化情况.结果 原代培养神经干细胞Nestin表达阳性,体外培养可分化为神经元和神经胶质细胞;BAC处理后,HE染色及免疫组织化学染色显示小鼠结肠肌间及黏膜下神经节消失;神经干细胞移植后各观测时间点可见荧光标记细胞,免疫组织荧光检测显示术后1周结肠壁存在巢蛋白(Nestin)表达阳性细胞,3周后可见神经元特异性烯醇化酶(NSE)及胶质纤维酸性蛋白(GFAP)表达阳性细胞,对照组未观察到阳性表达.结论 神经干细胞可以在去神经节小鼠结肠肇内存活并分化为神经元及胶质细胞,部分恢复肠道神经的调节作用.     

细胞黏附分子在先天性巨结肠症中的表达

目的　观察先天性巨结肠症 (HD)患者细胞黏附分子 (CAMs)在神经节正常肠段和神经节缺如肠段的表达情况。探讨CAM 成纤维细胞生长因子 (FGFR)信号传导在HD致病机制中的作用。方法　应用链酶抗生素蛋白 生物素 过氧化酶复合体法 (SABC) ,检测 16例HD患者中神经节正常和缺如肠段中CAMs的表达。结果　神经节细胞黏附分子 (NCAM )和神经元细胞钙黏素(N cadherin)在神经组织和平滑肌组织中都有表达 ,但在神经节正常肠段 (NG )肠组织中NCAM和N cadherin染色的神经纤维的数量明显多于神经节缺如肠段 (AG)。结论　CAMs在AG肠段的明显减少说明HD患者中CAM FGFR信号传导发生了异常 ,可能是导致肠神经母细胞移行障碍的原因之一。     

FasL基因表达对结直肠癌细胞肝转移影响的研究

目的　探讨FasL基因表达对结直肠癌细胞生物学行为的影响及在肝转移中的作用。方法　采用RT PCR方法检测大肠癌原发灶、癌旁肠黏膜、肝转移灶中FasL基因表达。用细胞转染方法 ,将FasLcDNA转染人直肠癌细胞HR 8348,采用四唑蓝法观测FasL表达对癌细胞生长抑制率及对5 FU、卡铂杀伤作用的影响。　结果　结直肠癌原发灶 (5 8例 )、癌旁肠黏膜 (5 8例 )、肝转移灶 (2 8例 )中FasL基因表达阳性率分别为 2 4 % (14 /5 8)、14 % (8/5 8)、10 0 % (2 8/2 8)。肝转移灶中FasL表达阳性率高于癌原发灶 (χ2 =4 3 4 9,P <0 0 1)和癌旁肠黏膜组织 (χ2 =5 7 6 6 ,P <0 0 1)。肝转移组原发灶FasL表达阳性率高于无肝转移组 (χ2 =3 96 ,P <0 0 5 )。转染HR 8348细胞FasL表达为阳性。用 5 FU、卡铂杀伤FasL转染细胞和未转染细胞 ,2组癌细胞生长抑制率有显著性差异 (t=9 0 2、t=11 93,P <0 0 1)。在相同化疗药物浓度下 ,FasL阳性HR 8348细胞存活率高于对照组癌细胞。　结论　FasL阳性癌细胞对化疗药物有较强的耐受性。FasL基因表达能使癌细胞逃避免疫监视和杀伤并对化疗药物产生抗性 ,促进结直肠癌发生肝转移。     

大鼠脊髓损伤后神经营养素及受体表达的变化

目的:观察神经营养素及受体在脊髓损伤后的表达变化。方法:SD大鼠30只,设正常组、假伤组、脊髓损伤组。Allen's法复制5g×10cm脊髓损伤模型。用免疫组化和免疫电镜方法观察各组神经生长因子(NGF)、脑源性神经营养因子(BDNF)、神经营养素-3(NT-3)及其受体TrkA,TrkB,TrkC表达的变化。结果:正常大鼠脊髓神经营养素及其受体表达较少,损伤后表达明显增加。NGF和BDNF伤后1～7d持续高表达,NT-3、TrkA、TrkB和TrkC伤后1～3d表达较高,与正常组和假伤组相比,差异有显著性意义。结论:神经营养素及受体在急性脊髓损伤中表达增加,起保护性作用。     

人骨肉瘤组织中Survivin mRNA的表达及与细胞凋亡的关系

目的　观察人骨肉瘤中Survivin基因表达 ,探讨其与细胞凋亡关系及对骨肉瘤生物学行为的影响。方法　采用原位杂交、免疫组织化学技术、DNA原位末端标记技术对 3 8例骨肉瘤、15例骨软骨瘤、5例正常骨组织SurvivinmRNA及骨肉瘤中Caspase 3蛋白和细胞凋亡进行检测。结果　较正常骨 (0 % )和骨软骨瘤 (6.7% ) ,SurvivinmRNA显著表达于骨肉瘤 (65 .8% )中 ,并与骨肉瘤WHO分型和转移有关 (P <0 .0 5 ) ;骨肉瘤中Caspase 3蛋白与凋亡细胞阳性率分别为71.1%和 63 .2 % ,凋亡指数 (AI)均值为 8.3 % ;Survivin阴性组AI显著高于阳性组 (P <0 .0 1) ;Sur vivin与Caspase 3表达不相关。 结论　Survivin选择性表达于骨肉瘤中 ,通过抑制细胞凋亡 ,参与骨肉瘤发生发展 ,其可能是判断骨肉瘤预后的重要参考指标。     

先天性巨结肠病因研究进展

先天性巨结肠 (Hirschsprung' s disease,简称HD)是一种肠神经系统 (Enteric nervoussystem,简称 ENS)发育异常的疾病 ,又称无神经节细胞症。其发病率大约是 1 /5 0 0 0 ,Okamoto等研究发现 :肌间神经丛系由神经母细胞形成。这些神经母细胞于胚胎第 5周开始沿迷走神经干由头侧向尾侧迁移 ,于第 1 2周到达消化道远端 ,而黏膜下层的神经节细胞由肌间神经母细胞移行过去的。故 HD的发生是由于各种原因导致神经母细胞迁移过程发生停顿所致。国际最新研究表明 ,HD是一种多基因控制的疾病 ,一些基因的缺失或突变是导致肠管发育障碍的根本原因…     

家兔面神经损伤后穴位针刺对神经生长因子及其受体表达的影响

目的 :观察穴位电针刺激对家兔面神经再生过程中神经生长因子及其受体表达的影响。 方法 :日本大耳白兔面神经压榨伤后 ,电针刺激翳风、颧、地仓、颊车、四白、阳白、合谷穴 ,每天 30min ,2周为 1疗程。设对照组。经 1、2、3疗程治疗后 ,应用原位杂交及RT PCR技术检测针刺组及对照组面神经核、面神经、表情肌中神经生长因子及其受体mRNA表达水平的变化。 结果 :两组三种组织中 ,神经生长因子及其受体表达高峰均出现在神经损伤后第 6周 ;表情肌组织中 ,针刺组神经生长因子及其受体TrkA、TrkCmRNA的表达明显高于对照组 (P <0 .0 5或 0 .0 1 ) ,另一受体TrkB无明显差异 (P >0 .0 5 ) ;神经组织中 ,受体TrkCmRNA的表达显著高于对照组 (P <0 .0 1 ) ,其它指标无显著差异 (P >0 .0 5 )。 结论 :在面神经再生过程中 ,穴位电针刺激能明显增强表情肌组织中神经生长因子及其受体TrkA、TrkC及神经组织中受体TrkCmRNA的表达 ,从而对神经再生起促进作用。     

324例肠神经元发育异常患儿病理特点与术后并发症关系分析

目的 探讨肠神经元发育异常的病理特点及其与术后并发症之间的关系。方法 总结324例肠神经元发育异常患儿的术后病理检查的特点,并对照相应的治疗效果和术后并发症,进行统计分析。结果 324例患儿中,先天性巨结肠（Hirschsprung＇s disease,HD）210例,肠神经元发育不良（intestinal neuronal dysplasia,IND）38例,HD伴IND45例,神经节细胞减少症8例,HD伴神经细胞节减少22例,神经节细胞未成熟症1例。不同病理类型在扩张段神经元正常的比例分别为HD88,1％,HD伴IND24,4％,IND18,4％,神经节细胞减少症4／8,HD伴神经细胞节减少27．7％,神经节细胞未成熟症0／1。全组有46例患儿术后出现反复小肠结肠炎（EC）。HD、HD伴IND、IND患儿的术后反复EC发生率分别为6,7％、35,6％、28．9％;切缘正常组与切缘IND组术后反复EC发生率分别为8,7％、38．2％;经肛门手术和经腹手术术后EC的发生率分别为18．0％和8．3％。术后仍有反复腹胀、便秘或严重的EC行再次手术9例,其中4例为HD伴IND,1例为IND,3例HD,1例HD伴神经细胞节减少。结论 肠神经元发育异常的神经元分布与大体病理改变有不平衡性,巨结肠同源病较HD神经元分布更不典型;单纯HD的治疗效果较好,术后小肠结肠炎发生率低;切缘仍有IND病变以及经肛门手术是术后反复EC的危险因素;术中冰冻切片对判断切缘神经元有重要意义;IND的切除范围仍有不确定性。     

大鼠脊髓腹侧左迫损伤后神经营养素及受体表达的变化规律

目的：探讨脊髓损伤后脊髓功能恢复的分子生物学基础。方法：在制作脊髓腹侧压迫损伤的基础上,应用免疫组织化学的方法观察几种神经营养素及其受体表达的变化规律。结果：脊髓腹侧压迫损伤后BDNF,GNDF,NT3,NGF以及TrkA,TrkB,TrkC在伤后3h表达开始增加,伤后72h达到高峰,在伤后2周内其表达维持在相对较高的水平,且以BDNF及TrkB表达最明显。结论：脊髓损伤后这些内源性神经营养素及其受体的大量表达对受损伤脊髓的功能恢复起重要作用。同时也反映了受试动物的脊髓功能受损较重的特点。     

先天性巨结肠层粘连蛋白基因及RET基因的表达研究

目的:通过对先天性巨结肠(HD)病变段层粘连蛋白(LN)转录表达的研究,探讨肠壁微环境改变对HD的形成作用以及与RET基因学说的相关性。方法:利用RT-PCR技术对HD病儿层粘连蛋白mRNA在无神经节细胞段、有神经节细胞段、正常段的表达进行检测,美国alpha9900凝胶图像分析系统判定表达强度,SPSS软件统计分析,推断LN的作用,同时检测RET基因的表达,用直线相关关系研究两者的相关性。结果:LN基因在无神经节细胞段异常高表达(P〈0.05),无神经节细胞段〉有神经节细胞段〉正常段;而RET基因的表达正好相反,无神节细胞段〈有神经节细胞段〈正常段,在无神经节细胞段明显减少,两者存在负相关关系。结论:HD无神经节细胞段LN的增高是内在的,LN增高引起肠神经细胞过早分化、定居导致无神经节细胞症的发生,可能与RET基因有一定内在联系。     

先天性巨结肠不同节段肠壁神经、平滑肌的分布及临床意义

目的 观察先天性巨结肠(HD)不同节段肠壁神经和平滑肌的病变范围,探讨先天性巨结肠根治术后肠动力功能紊乱原因及手术切除结肠范围.方法 用免疫组织化学和苏木素-伊红(HE)染色法,检测20例先天性巨结肠肠壁神经节细胞、神经纤维和平滑肌细胞病理组织学改变及分布范围.结果 巨结肠不同节段肠壁神经节细胞、神经纤维数量及突触素(Syn)、神经节细胞黏附分子(NCAM)的阳性表达,在距扩张远端8 cm虽未达到正常,但与对照组差异减小(P＞0.05).环肌层和纵肌层出现不同程度增厚,在距扩张远端8 cm仍未正常(P＜0.01).肌层出现空泡样变,与对照组比较差异无统计学意义(P＞0.05).结论 先天性巨结肠切除段肠壁神经、平滑肌层均存在病变,在距扩张段的远端8 cm处,两者病变总体缓解.在允许情况下,手术切除结肠的范围应达到或超过此范围.     

Calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of Hirschsprung's disease

Background/Purpose

Identifying ganglion cells by rectal suction biopsy is a basic diagnostic tool for the diagnosis of Hirschsprung's disease (HD). However, the difficult interpretation of conventionally processed slides often necessitates ancillary staining methods. The aim of this study was to evaluate the usefulness of calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of HD.

Methods

We analyzed 52 rectal suction biopsy specimens (37 from 15 HD patients and 15 from 7 non-HD patients) for ganglion cells with calretinin and MAP-2 immunohistochemistry. We also analyzed full-thickness, frozen biopsy samples obtained from 15 HD patients who underwent surgery utilizing calretinin and MAP-2 immunohistochemistry.

Results

Both calretinin and MAP-2 positively stained ganglion cells in the submucosal plexus of the ganglionic bowel but not aganglionic bowel. Calretinin usually stained ganglion cell cytoplasm and nuclei more intensely than MAP-2, which only stained cytoplasm. No nerve fiber staining in the submucosal layer was observed for either antibody. In 21.1% (11/52) of samples, calretinin and MAP-2 staining found ganglion cells which were reported not to have ganglion cells in the original surgical pathology reports. Immunohistochemical staining for calretinin using paraffin-embedded tissue sections after cryostat sections clearly demonstrated decreased staining intensity compared to MAP-2.

Conclusion

Calretinin and MAP-2 are useful diagnostic markers for diagnosing HD in rectal suction biopsies. These complementary methods could ameliorate the diagnostic difficulties associated with HD.     

Decreased tyrosine kinase C expression may reflect developmental abnormalities in Hirschsprung's disease and idiopathic slow-transit constipation

BACKGROUND: Some patients with Hirschsprung's disease have refractory constipation following excision of aganglionic bowel, as do patients with idiopathic slow-transit constipation (STC). Gut motility depends on enteric neuronal development in response to expression of trophic factors and their receptors. Recent studies indicate the importance of neurotrophin 3 (NT-3) and its high-affinity receptor tyrosine kinase C (trk C) in enteric neuronal development. METHODS: Blinded quantitative immunohistochemical analysis of colon from patients with Hirschsprung's disease (aganglionic, hypoganglionic and normoganglionic) (n = 5), STC (n = 6) and appropriate age-matched control tissues (n = 5) was performed for NT-3 and trk C. Sural nerve morphometry and immunostaining were undertaken in three patients with STC who had abnormalities on limb autonomic and sensory testing. RESULTS: A significantly higher proportion of submucous plexus neurones was trk C immunoreactive in control infant than adult colon (mean(s.e.m.) 73(9) versus 16(3) per cent of the total; P < 0.001), in accord with a role in development. The proportion of submucous plexus trk C-immunoreactive neurones was reduced in colon from patients with Hirschsprung's disease (28(7) per cent of total in normoganglionic Hirschsprung's disease; P < 0.007 versus infant controls) and STC (10(1) per cent of total; P = 0.053 versus adult controls). No abnormalities of STC sural nerves were detected by morphometry or immunostaining. CONCLUSION: Decreased trk C expression may reflect developmental abnormalities in Hirschsprung's disease and idiopathic STC. Trk C activation by NT-3 or drugs may provide novel treatments. Presented in abstract form to the Pacific Association of Pediatric Surgeons, Las Vegas, Nevada, USA, May 2000     

Does Abnormal Expression of Acetylcholine Receptors in Hirschsprung's Disease Induce Acetylcholine Esterase Positive Nerve Fibres?

OBJECTIVE: Alpha bungarotoxin (alpha-BTX) is a neurotoxin isolated from the venom of Bungarus multicinctus that binds specifically to the beta-subunits of nicotinic acetylcholine receptors (nAChR) on myotube membranes. The purpose of the present study was to investigate the distribution of alpha-BTX-sensitive nAChR in Hirschsprung's disease (HD) to understand the histopathological features of HD, especially the increase in acetylcholine esterase (AChE) positive nerve fibres. METHODS: Confocal microscopy was used to study the expression of FITC (fluorescein isothiocyanate)-alpha-BTX, anti-synaptophysin (A-SY) antibody, and anti-neurofilament (A-NF) antibody to determine the distribution of nAChR and ganglion cell and nerve fibres in colon specimens from five cases of HD and three normal controls. RESULTS: Quantitative assessment of the immunoreactivity of colonic muscle and colonic mucosal epithelium from an aganglionic segment of HD bowel demonstrated markedly increased nAChR compared with colonic muscle and colonic mucosal epithelium from a ganglionic segment of HD bowel and normal bowel (p < 0.0001, respectively), both of which have only a few positive nAChR. In colonic muscle from aganglionic and transitional segments of HD, there were many nAChR around hypertrophic nerve trunks identified by A-NF and A-SY staining. CONCLUSION: We suggest that abnormal expression of nAChR in HD might be implicated in causing gastrointestinal dysmotility because of their localization around hypertrophic nerve trunks.     

Combined treatment of neurotrophin-3 gene and neural stem cells is propitious to functional recovery after spinal cord injury

We present an insight of the effects of combination therapy with neurotrophin-3 and neural stem cell on functional recovery after spinal cord injury (SCI). Total RNA was extracted from neural stem cell line C17.2 and reversed transcribed into cDNA. Neurotrophin-3 (NT-3) gene was amplified by PCR and subcloned into plasmid to construct an expression vector pNT-3. A positive clone containing pNT-3, named SHN2, was obtained and used for transplantation. Thirty adult mice received mechanical injury at the T8 vertebra level. Cell survival, NT-3 gene expression, and functional recovery were observed through X-Gal staining, RT-PCR, and open field locomotion, respectively. The results show that NT-3 gene comprising 777 bp nucleotides was cloned and a more than twofold expression was detected when transfected into neural stem cell line C17.2. Quantitative analysis of cellular density revealed a significant increase in SHN2 compared to the control cells (p < 0.01). Thirty days after transplantation, SHN2 showed significant increase near the lesion site. Furthermore, the functional recovery indicated an active effect by detecting Basso-Beattie-Bresnahan (BBB) locomotor rating scale (p < 0.01). In conclusion, combined treatment of neural stem cells and NT-3 gene can facilitate functional recovery. It offers an effective approach to treat SCI.     

神经营养因子-3基因移植的雪旺细胞延缓肌萎缩的实验研究

目的 探讨神经营养因子-3(neurotrophic factor-3,NT-3)基因修饰的雪旺细胞(Schwann cells,SC)延缓失神经性肌肉萎缩的作用.方法 采用双酶消化法和贴壁法培养、纯化与传代SC.应用阳离子脂质体以NT-3基因修饰SC,免疫组织化学S-100染色检测NT-3基因转入前后SC的纯度.切断右侧胫神经建立腓肠肌失神经支配的动物模型.将104只SD大鼠按注射药物的不同随机分为4组,每组26只.A组,细胞外基质(extracellular matrix,ECM)凝胶组;B组,SC-ECM凝胶组;C组,NT-3基因-ECM凝胶组;D组,NT-3基因修饰的SC-ECM凝胶组.术后12周进行腓肠肌肌肉电生理,8周和12周做肌湿重、肌纤维横截面积的检测.结果 NT-3转染前后SC纯度分别为(94.7±2.1)%及(95.6±2.5)%,两者比较差异有统计学意义(P＜0.05).术后12周用电刺激腓肠肌,均可引出肌肉收缩活动;且随着时间的延长,单次收缩的波幅、速度,及强直收缩的时间和强直收缩波幅的恢复率均增加.D组均优于B、C组,B、C组均优于A组(P＜0.05),而B、C组相比差异无统计学意义(P＞0.05).术后8周和12周的肌湿重与肌纤维横截面积D组均优于B、C组,B、C组均优于A组(P＜0.05),而B、C组相比差异无统计学意义(P＞0.05).结论 转染NT-3基因的SC移植能够实现失神经骨骼肌的神经再支配,并且能与骨骼肌建立起功能性突触连接,有延缓失神经性骨骼肌萎缩的作用.     

Intestinal neuronal dysplasia is a possible cause of persistent bowel symptoms after pull-through operation for Hirschsprung's disease

The proximal margin of the resected bowel specimens from 33 consecutively treated patients undergoing a definitive pull-through operation for Hirschsprung's disease (HD) and control specimens consisting of suction rectal biopsy specimens obtained from 24 age-matched patients evaluated for constipation (and proven not to have HD) were examined using conventional H&E staining and acetylcholinesterase (AChE) histochemistry. Complete resection of the aganglionic segment was confirmed in 31 patients. In one patient, the proximal margin was found to be aganglionic; in another, the proximal margin was in a transitional zone. In both patients, frozen sections at the time of surgery were interpreted as having ganglion cells. In 10 of 31 patients, intestinal neuronal dysplasia was demonstrated in the proximal margin of the resected bowel. The abnormalities included hyperplasia of the submucous plexus, giant ganglia (with > 7 ganglion cells), and ectopic ganglion cells (all 10 patients) and increased AChE activity in the lamina propria (5 patients). All ten patients with IND had persistent bowel problems after the definitive operation for HD, such as enterocolitis, soiling, or constipation. Only four of the other 21 patients had persistent bowel symptoms. This study suggests that IND is commonly associated with HD. It also emphasizes the importance of histochemical examination of the resected segment to predict postoperative bowel function in patients with HD.     

TrkC overexpression enhances survival and migration of neural stem cell transplants in the rat spinal cord

Although CNS axons have the capacity to regenerate after spinal cord injury when provided with a permissive substrate, the lack of appropriate synaptic target sites for regenerating fibers may limit restoration of spinal circuitry. Studies in our laboratory are focused on utilizing neural stem cells to provide new synaptic target sites for regenerating spinal axons following injury. As an initial step, rat neural precursor cells genetically engineered to overexpress the tyrosine kinase C (trkC) neurotrophin receptor were transplanted into the intact rat spinal cord to evaluate their survival and differentiation. Cells were either pretreated in vitro prior to transplantation with trkC ligand neurotrophin-3 (NT-3) to initiate differentiation or exposed to NT-3 in vivo following transplantation via gelfoam or Oxycel. Both treatments enhanced survival of trkC-overexpressing stem cells to nearly 100%, in comparison with approximately 30-50% when either NT-3 or trkC was omitted. In addition, increased migration of trkC-overexpressing cells throughout the spinal gray matter was noted, particularly following in vivo NT-3 exposure. The combined trkC expression and NT-3 treatment appeared to reduce astrocytic differentiation of transplanted neural precursors. Decreased cavitation and increased beta-tubulin fibers were noted in the vicinity of transplanted cells, although the majority of transplanted cells appeared to remain in an undifferentiated state. These findings suggest that genetically engineered neural stem cells in combination with neurotrophin treatment may be a useful addition to strategies for repair of spinal neurocircuitry following injury.     

Selective neurotrophin deficiency in infantile hypertrophic pyloric stenosis

BACKGROUND/PURPOSE: Increasing evidence suggests that the enteric nervous system is under the control of neurotrophins. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5), promote differentiation, growth, and survival of various central and peripheral nervous system neurons. The biological effects of neurotrophins are mediated by the interactions with high-affinity tyrosine kinase receptors (TrkA, TrkB, TrkC). Recently, abnormalities of intramuscular innervation have been reported in infantile hypertrophic pyloric stenosis (IHPS). To further understand the reported abnormalities in pyloric innervation in IHPS, the authors analyzed the expression of Trk receptors and the neurotrophins content in IHPS. METHODS: Full-thickness muscle biopsy specimens were obtained from 8 IHPS patients (age range, 23 to 41 days) at pyloromyotomy and from 8 age-matched controls without gastrointestinal disease at autopsy performed within 12 hours after death. Indirect immunohistochemistry was performed using ABC (Avidin Biotin peroxidase Complex) method with anti-Trk specific antibodies (A,B,C). Quantitative analysis was performed using sandwich-type ELISA for NGF, BDNF, NT-3, and NT-4/5. RESULTS: The intensity of staining of the myenteric plexus for TrkA, TrkB, and TrkC was similar among IHPS and controls. There was a lack of TrkA-positive nerve fibers in IHPS compared with controls. The quantity of total NGF, NT-3, and BDNF in IHPS was significantly lower than in controls. CONCLUSIONS: The reduced production of neurotrophins in IHPS may be responsible for the delay in the functional and structural maturation of pyloric innervation in IHPS. The lack of TrkA-positive nerve fibers in pyloric muscle may explain the abnormal intramuscular innervation in IHPS.