胎儿肠道神经细胞群体的计算机三维重建

本文研究了胎儿肠道神经细胞(胞体)群体连续切片图象的计算机三维重建及显示。首次利用行程编码压缩离散群体的三维重建数据,以降低对计算机内存的需求及提高三维重建速度。在截面重建法的基础上,引入仿射变换作为旋转、投影变换,以实现不同角度观察细胞群体的三维空间结构及形状。理论分析和实验研究均表明:本文的方法能在微机上同时实现多个细胞体的三维重建及显示。最后展示了一些不同角度的胎儿肠道神经元胞体的重建显示结果图象并进行了讨论。

腹部推拿对便秘型肠易激综合征家兔ENS-ICC-SMC结构的影响

目的:验证腹部推拿对肠易激综合征(irritable bowel syndrome,IBS)家兔胃肠动力障碍的调节作用,观察腹部推拿对IBS家兔肠神经细胞、Cajal间质细胞和肠道平滑肌细胞连接结构的影响。方法:将家兔分为空白对照组、模型对照组和腹部推拿组,采用FITC标记微球灌胃,在不同时间点观察胃、小肠、结肠的微球分布情况,免疫荧光染色检测肠组织中C-Kit、nNOS表达情况,电镜观察ENS-ICC-SMC超微结构。结果:空白对照组微球主要分布在小肠,而模型对照组主要分布在胃部,腹部推拿组结肠荧光强度增强;与模型对照组比较,腹部推拿组C-Kit和nNOS表达增加,电镜观察腹部推拿组ENS-ICC-SMC超微结构更接近于空白对照组。结论:腹部推拿对IBS家兔胃肠动力障碍具有调节作用,其作用机制可能与其对肠ENS-ICC-SMC结构的影响有关。

c—kit在肠神经节细胞发育过程中的作用

目的初步探讨c-kit在肠神经节细胞发育中的作用。方法体外培养大鼠肠神经节细胞及骨髓间充质干细胞（BMSCs），并在GDNF与胎肠培养基（FGCM）培养的条件下诱导BMSCs分化为肠神经节细胞。免疫组织化学方法鉴定原代培养的肠神经节细胞神经丝蛋白（neurofilament，NF）的表达，用血管活性肽（vasoactive intestinal peptide，VIP）及NF鉴定BMSCs诱导分化的肠神经节细胞。RT-PCR分别检测原代肠神经节细胞、BMSCs以及诱导之肠神经节细胞的c—kit的表达。结果免疫组化结果显示纯化后的肠神经节细胞表达NF，流式细胞学检测第四代后的BMSCs高表达CD90，而不表达CD45，诱导后的肠神经节细胞可表达VIP及NF，而其余两组则不表达。RT-PCR结果示原代肠神经节细胞及BMSCs不表达c-kit，诱导后的肠神经节细胞可表达c-kit。结论在体外能成功培养大鼠肠神经节细胞及BMSCs并纯化，BMSCs可被诱导为肠神经节细胞并表达肠神经递质。在肠神经系统的发育过程中，c-kit可能在某一阶段起到一定作用，在肠神经细胞逐渐发育成熟时接受到某些信号而关闭。

Apoptosis of human colon carcinoma HT-29 cells induced by ceramide

AIM： To investigate the effect of exogenous ceramideinduced apoptosis on human colon carcinoma HT-29 cells. METHODS： Light microscope, transmission electron microscope and fluorescence microscope were used to observe the morphology change of apoptosis in HT-29 cells. Agarose gel electrophoresis was performed to detect the DNA fragment. Mitochondrial function was detected by MTT assay, mRNA expression of Bcl-2 family gene members was determined by reverse transcription polymerase chain reaction （RT-PCR） assay. RESULTS： After C2-ceramide treatment, typical characteristics of apoptosis, such as nuclear chromatin breakage, apoptotic body and DNA ladder, could be observed. After exposure to 50μmol/L C2-ceramide for 12 and 24 h, cell apoptosis was 64.1% and 81.3% respectively, which had a time-and dose-effect relationship. Mitochondrial function started to decrease from 6 h after exposure to ceramide. Meanwhile, ceramide up-regulated or down-regulated the mRNA expression of Bcl-2 family gene members. CONCLUSION： Ceramide induces apoptosis of human colon carcinoma HT-29 cells by affecting the expression of Bcl-2 family gene members and impacting the mitochondrial function.

Enteric glial cells and their role in gastrointestinal motor abnormalities: Introducing the neuro-gliopathies

The role of enteric glial cells has somewhat changed from that of mere mechanical support elements, gluing together the various components of the enteric nervous system, to that of active participants in the complex interrelationships of the gut motor and inflammatory events. Due to their multiple functions, spanning from supporting elements in the myenteric plexuses to neurotransmitters, to neuronal homeostasis, to antigen presenting cells, this cell population has probably more intriguing abilities than previously thought. Recently, some evidence has been accumulating that shows how these cells may be involved in the pathophysiological aspects of some diseases. This review will deal with the properties of the enteric glial cells more strictly related to gastrointestinal motor function and the human pathological conditions in which these cells may play a role, suggesting the possibility of enteric neuro- gliopathies.

Isolated intestinal neurofibromatous proliferations in the absence of associated systemic syndromes

Gastrointestinal tract involvement by neurofibromatous lesions is rare and occurs most frequently as one of the systemic manifestations of generalized neurofibromatosis type 1 （NF1）. In this setting, the lesions may manifest as focal scattered neurofibromas or as an extensive diffuse neural hyperplasia designated ganglioneuromatosis. Occasionally, such lesions may be the initial sign of NF1 in patients without any other clinical manifestations of the disease. Rarely, cases of isolated neurofibromatosis of the large bowel with no prior or subsequent evidence of generalized neurofibromatosis have been documented. We present the case of a 52 year-old female with abdominal pain and alternating bowel habits. Colonoscopic evaluation revealed multiple small polyps in the cecum and the presence of nodular mucosa in the colon and rectum. Pathologic evaluation of the biopsies from the cecum, descending colon, sigmoid colon, and rectum revealed tangled fascicles of spindle cells expanding the lamina propia leading to separation of the intestinal crypts. Immunohistochemical stains helped confirm the diagnosis of diffuse intestinal neurofibromatosis. A thorough clinical evaluation failed to reveal any stigmata of generalized neurofibromatosis. This case represents a rare presentation of isolated intestinal neurofibromatosis in a patient without classic systemic manifestations of generalized neurofibromatosis and highlights the need in such cases for close clinical follow-up to exclude neurofibromatosis type I or multiple endocrine neoplasia type Ⅱ.

S100B protein in the gut:The evidence for enteroglial-sustained intestinal inflammation

Glial cells in the gut represent the morphological and functional equivalent of astrocytes and microglia in the central nervous system （CNS）. In recent years, the role of enteric glial cells （EGCs） has extended from that of simple nutritive support for enteric neurons to that of being pivotal participants in the regulation of inflammatory events in the gut. Similar to the CNS astrocytes, the EGCs physiologically express the SIOOB protein that exerts either trophic or toxic effects depending on its concentration in the extracellular milieu. In the CNS, SIOOB overexpression is responsible for the initiation of a gliotic reaction by the release of pro-inflammatory mediators, which may have a deleterious effect on neighboring cells. SlOOB-mediated pro-inflammatory effects are not limited to the brain： SIOOB overexpression is associated with the onset and maintenance of inflammation in the human gut too. In this review we describe the major features of EGCs and SIOOB protein occurring in intestinal inflammation deriving from such.

New techniques in the tissue diagnosis of gastrointestinal neuromuscular diseases

Gastrointestinal neuromuscular diseases are a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular (including interstitial cell of Cajal) dysfunction. Common to most of these diseases are symptoms of impaired motor activity which manifest as slowed or obstructed transit with or without evidence of transient or persistent radiological visceral dilatation. A variety of histopathological techniques and allied investigations are being increasingly applied to tissue biopsies from such patients. This review outlines some of the more recent advances in this fi eld, particularly in the most contentious area of small bowel disease manifesting as intestinal pseudo-obstruction.

Hirschsprung's disease:Is there a relationship between mast cells and nerve fibers?

AIM:To define the topography of mast cells and their numbers in cases of Hirschsprung's disease(HD)and non-HD,assess neural hypertrophy using imaging software and to study the relationship between mast cells and nerve fibers.METHODS:HE stained sections of 32 cases of chronic constipation in the age group of 0-14 years were reviewed for ganglion cells.AChE staining was performed on frozen sections of colonic and rectal biopsies.Based on their findings cases were divided into HD and non-HD and mast cells stained by toluidine blue were evaluated.Image analysis by computerized software was applied to S-100 stained sections for assessment of neural hypertrophy.RESULTS:Difference between number of mast cells in HD group(mean=36.44)and in non-HD group(mean =14.79)was statistically significant.Image analysis morphometry on S-100 stained sections served as a useful adjunct.The difference between number,size,and perimeter of the nerve fibers between HD and non-HD group was statistically significant.CONCLUSION:Mast cells are significantly increased in HD and their base line values are much higher in Indian children than that reported in Western literature.Their role in HD needs further research.Morphometry of S-100 stained nerve fibers is a useful adjunct to conventional methods for diagnosis of HD.

Nestin in gastrointestinal and other cancers: Effects on cells and tumor angiogenesis

Nestin is a class Ⅵ intermediate filament protein that was originally described as a neuronal stem cell marker during central nervous system (CNS) development, and is currently widely used in that capacity. Nestin is also expressed in non-neuronal immature or progenitor cells in normal tissues. Under pathological conditions, nestin is expressed in repair processes in the CNS, muscle, liver, and infarcted myocardium. Furthermore, increased nestin expression has been reported in various tumor cells, including CNS tumors, gastrointestinal stromal tumors, pancreatic cancer, prostate cancer, breast cancer, malignant melanoma, dermatofibrosarcoma protuberances, and thyroid tumors. Nestin is reported to correlate with aggressive growth, metastasis, and poor prognosis in some tumors; however, the roles of nestin in cancer cells have not been well characterized. Furthermore, nestin is more specifically expressed in proliferating small-sized tumor vessels in glioblastoma and gastric, colorectal, and prostate cancers than are other tumor vessel markers. These findings indicate that nestin may be a marker for newly synthesized tumor vessels and a therapeutic target for tumor angiogenesis. It has received a lot of attention recently as a cancer stem cell marker in various cancer cells including brain tumors, malignant rhabdoid tumors, and uterine, cervical, prostate, bladder, head and neck, ovarian, testicular, and pancreatic cancers. The purpose of this review is to clarify the roles of nestin in cancer cells and in tumor angiogenesis, and to examine the association between nestin and cancer stem cells. Nestin has the potential to serve as a molecular target for cancers with nestin-positive cancer cells and nestin-positive tumor vasculature.

Mucosal Schwann cell “Hamartoma”:A new entity?

Schwannoma is a well-described,benign nerve sheath tumor of the soft tissue,but is rare in the gastrointestinal tract.Gastrointestinal schwannomas are often incidentally discovered as small polypoid intraluminal lesions.In this report,we describe the clinicopathologic and immunohistochemical features of a distinctive neural mucosal polyp composed of a diffuse cellular proliferation of uniform bland spindled cells in the lamina propria that entraps the colonic crypts.Immunohistochemical analysis revealed strong and diffuse positivity for the S-100 protein.To avoid confusion of these solitary colorectal polyps containing pure spindled Schwann cell proliferation in the lamina propria with neural lesions that have significant association with inherited syndromes,it is better to use the designation "mucosal Schwann hamartoma".

Giant mesenteric neurofibromas:a case report

We presented a case of giant neurofibromas arising from the jejunal mesentery of a 52-year-old man. The patient presented with epigastric fullness, and decrease of food intake, but without stigmata of neurofibromatosis-l. Ultrasonography, computed tomography （CT） and MR imaging revealed two large masses in the abdomen extending to the pelvis. Total resection of the tumors together with corresponding segments of intestines was performed. Histological examination and immunocytochemistry for S-100 protein confirmed the masses to be multiple neurofibromas of the mesentery. We also discussed the clinical features, and treatment approaches of similar cases in literatures.