Two- Versus Three-Dimensional In Vitro Differentiation of Human Pulp Cells Into Odontoblastic Cells

The spatial organization of the pulp cells may modify the cytodifferentiation process. The purpose of this study was to compare the two- versus three-dimensional cell culture systems for differentiation of human odontoblastic cells in vitro. Pulpal cores from freshly extracted human third molars were cultured in vitro in a perfusion device on two types of membranes: polyester membrane (two-dimensional [2D] cell culture) and nylon mesh (three-dimensional [3D] cell culture). The cells were incubated with minimum essential medium containing (a) substitute serum, (b) 10% fetal calf serum (FCS), (c) 10% fetal calf serum + 2 mM &#103 -glycerophosphate ( &#103 GP), and (d) 10% fetal calf serum + transforming growth factor (TGF) &#103 1. Immunohistochemistry was used to evaluate the expression of collagen I, osteonectin, and nestin. Small differences were observed between 2D and 3D cell culture systems. This was particularly evident in the 10% FCS group. &#103 -Glycerophosphate in the 3D system seems to stimulate the osteogenic cell phenotype, as a considerable induction of osteonectin is observed.     

碱性成纤维细胞生长因子对牙周细胞生物学活性的影响

目的：观察基因重组入碱性成纤维细胞生长因子（rh-bFGF)牙龈成纤维细胞（GF）、人牙周韧带成纤维细胞（PDLF）及人牙槽骨细胞（ABC）的增殖、碱性磷酸酶活性、总蛋白含量及对3种细胞矿化结节形成能力的影响。方法：采用细胞培养、MTT比色测定、碱性磷酸酶测定法、考马宙蓝法及茜素红染色法。结果bFGF能促进3种细胞的增殖,但对PDLF和ABC的ALP活性,蛋白含量及矿化结节的形成有抑制作用。结论bFGF可促进细胞的增殖,抑制细胞的分化成熟,从而促进牙周再生。     

己烯雌酚对未成熟大鼠卵巢卵泡颗粒细胞分化的形态学观察

取出生后21～26天Sprague-Dawley未成熟雌性大鼠,分为实验与对照两组。实验组只/天注射己烯雌酚(DES)0.5mg(溶于芝麻油中),并按注射天数分为2、3、4、5天组;对照组注射等量的芝麻油。注射2天后,逐日取材固定,用光镜和电镜观察两组动物的卵巢和卵泡颗粒细胞。同时从各组卵巢中分离出卵泡颗粒细胞,用无血清McCoy 5a培养基培养,加入不同的激素,分为对照组、FSH组、DES+FSH组、FSH+hCG组。培养3天后,取材固定,用光镜、透射电镜、扫描电镜观察各组的细胞形态,结果为:1.实验组卵巢比对照组的大,卵泡也大。卵泡细胞增多,细胞体积大,分裂象多见。2.注射3天以上DES的卵巢中,闭锁卵泡和退化的卵泡细胞增多。3.电镜下,实验组卵泡细胞中与蛋白质合成有关的细胞器比对照组发达。4.体外培养的卵泡颗粒细胞,对照组细胞排列分散;FSH组细胞集聚成团,细胞表面微绒毛增多;细胞质内与合成蛋白质有关的细胞器比对照组的发达。DES+FSH组的细胞排列和结构与FSH组的相似。FSH+hCG组细胞体积增大,细胞表面微绒毛减少或消失。细胞质内出现滑面内质网,细胞开始黄体化。5.注射2～5天DES的各组细胞形态和结构均相似。从形态学来看,经DES处理的未成熟雌鼠的卵泡颗粒细胞的形态、排列和对不同激素作用下的变化,与文献报道的去垂体雌鼠的同类细胞相似。因此我们认为,未成熟雌鼠的卵泡颗粒细胞也能作为研究细胞分化的一种模型。     

Cytodifferentiation and immunocharacteristics of adenohypophysial cells in the toad, Bufo melanostictus

Summary Employing the unlabelled antibody enzyme technique cytodifferentiation, immunocharacteristics and topographical distribution of melanotropic (MSH), adrenocorticotropic (ACTH), thyrotropic (TSH), prolactin (PRL), gonadotropic (GTH) and growth hormone (GH) secreting cells in the embryonic/larval as well as adult pituitary gland of the common Indian toad, Bufo melanostictus, have been studied by using antisera raised in rabbit against mammalian hypophysial hormones. Immunoreactive MSH and ACTH cells appear first in the dorsocaudal and rostral regions of the pituitary anlage (PA) at stage 21 (Gosner's classification) of the embryonic development. This is followed by the differentiation of TSH and PRL cells at stage 22 in the midventral and central regions of the PA respectively. Finally, at stage 23 the GTH cells appear in the fostral and the GH cells in the caudal regions of the PA. With the progress of the development, cells showing immunoreactivity to various antisera gradually increase in number, size, granular content and finally occupy the characteristic adult disposition. The MSH cells comprise the pars intermedia. In the pars distalis (PD) the ACTH cells are localized in the rostroventral region, TSH cells in the central region and the GH cells in the dorsocaudal region. However, GTH and PRL cells are distributed throughout the PD.Dedicated to Late Dr. Maurice P. Dubois     

Production of congenital limb defects with retinoic acid: Phenomenological evidence of progressive differentiation during limb morphogenesis

Summary Maternal administration of a single dose of retinoic acid (vitamin A acid, 100 mg/kg) on either the 11 th, 11 1/2, 12th, 12 1/2, 13th or 13 1/2 day of gestation produced phocomelia or partial phocomelia in ICR/DUB fetuses. The results depended upon the time of treatment and two gradients of effect were produced: 1) cranio-caudal gradient, since forelimb defects resulted from treatment between days 11 and 13, while similar hindlimb abnormalities were produced by administration of retinoic acid 12 to 24 hours later: 2) proximo-distal gradient, due to the heterogenous sensitivity among individual bones of the limb. In the forelimb, early treatment (11th day) produced humero-ulnar defects and later treatment (12th day) ulnoradial defects. A similar proximo-distal gradient was observed in the hindlimb. The use of teratological studies as a tool to assist morphogenetic investigation is discussed.This work was supported by NIH-Grant No. HD-06550 awarded to Dr. Kochhar while at the University of Virginia, Charlottesville, Va.     

DKK1对脂多糖感染人牙髓细胞生物学行为的影响

目的:研究DKK1对脂多糖(lipopolysaccharide,LPS)感染人牙髓细胞生物学行为的影响.方法:使用改良酶组织块法分离培养人牙髓细胞并通过免疫荧光染色鉴定细胞来源;通过细胞计数试剂盒(CCK-8)、Transwell实验、茜素红染色、荧光定量PCR等实验检测DKK1对LPS感染人牙髓细胞的生物学行为的变...     

黏蛋白MUC-1在人胚胎胃黏膜发育中的阶段表达

目的 阐明MUC-1在胎儿胃黏膜的表达特点,探讨MUC-1与胃上皮分化的关系。方法 应用HE染色和SP免疫组织化学方法,检测22例9～30周胎儿胃黏膜的发育以及MUC-1在不同时期的表达。结果 胎儿胃黏膜的分化可分为3个不同时期：1．在未分化期MUC-1呈极性分布于早期胃上皮的游离面。2．在分化期MUC-1呈极性和弥漫性分布于中期胃黏膜上皮和腺上皮。3．生长期MUC-1分布于胃底腺上皮。结论 MUC-1的表达与胃上皮的分化密切相关。     

Cytodifferentiation of cochlear hair cells

Cytodifferentiation of a limited number of cochlear hair cells in the mouse starts on the 14th gestational day. One day later, the number of identified hair cells increases considerably. Cytodifferentiation apparently occurs in a gradient from the hair cell surface to the base. First, the irregular microvilli covering the future hair cell surfaces begin to show a regular pattern but are of the same thickness and length as microvilli on supporting cells. Second, a polarization of sensory hairs occurs with a stepwise increase in stereocilia length in the different rows toward the kinocilium. Finally, the cuticle is formed, giving an anchorage for sensory hair rootlets in the hair cell. At birth some hair cells can be found with immature surface morphologic features, e.g., stereocilia of the same length on the entire hair cell surface and lack of a cuticular plate. The onset of hair cell differentiation takes place without morphologic contact with ingrowing nerve fibers.     

IGF-1对小鼠牙囊细胞生物学特性的影响

目的:探讨胰岛素样生长因子-1(IGF-1)对小鼠牙囊细胞增殖、蛋白含量及分化能力影响。方法:将第3代小鼠牙囊细胞与不同浓度IGF-1(0.005、0.01、0.05、0.1、0.5 mg/L)共孵育后,测定IGF-1对细胞增殖、碱性磷酸酶活性、总蛋白含量的影响;并用Von Kossa法检测0.05和0.1 mg/L的IGF-1对牙囊细胞矿化结节形成能力的影响。结果:在0.05~0.1 mg/L的浓度范围内,IGF-1能显著促进牙囊细胞的增殖,使ALP活性及总蛋白含量增加(P<0.01),但三者的最佳效应浓度有所差异,当浓度升高至0.5 mg/L时,促进效应下降,与对照组无显著性差异(P>0.05);0.05和0.1 mg/L的IGF-1均能显著促进牙囊细胞矿化结节的形成(P<0.05,与对照组相比)。结论:合适浓度的IGF-1能促进牙囊细胞的增殖,增加蛋白含量及向成骨细胞(成牙骨质细胞)方向分化的能力。