Massuda Eduardo T, Oliveira José Antonio
Faculty of Medicine of the University of São Paulo, Ophthalmology, Otorhinolaryngology & Head and Neck Surgery, São Paulo, Brazil.
Laryngoscope. 2005 Mar;115(3):481-5. doi: 10.1097/01.mlg.0000157826.15756.67.
Cholesteatoma is a recurrent disease that is difficult control by otologists. This study aims to develop an experimental model of cholesteatoma that is easy to reproduce, using latex to induce the inflammatory reaction and propylene glycol as the foreign body in the middle ear.
We used a new experimental model in which an intentional perforation was performed on the tympanic membrane of rats, followed by the introduction of a latex biomembrane.
A control group was submitted only to perforation of the tympanic membrane. Propylene glycol with latex was used in experimental group 1 and latex alone in experimental group 2. The rats were killed during the eighth week and their tympanic bullae were stained with hematoxylin and eosin.
Eighty percent of the animals in group 1 and 90% in group 2 developed a cholesteatoma. No formation of cholesteatomas or inflammatory tissue occurred in the control group.
The presence of inflammatory cells may provoke the production of cytokines (IL-1, IL-2, IL-6, IL-8) and growth factors, which, together with the latex biomembrane, which is known to contain a protein that favors vascular growth, may cause chemotactic migration of the squamous epithelium from the external auditory meatus to the middle year of the rat, causing a cholesteatoma. The induction of an experimental cholesteatoma in rats with latex and latex plus 50% propylene glycol was effective, representing an excellent experimental model. The theory of epithelial migration in the genesis of cholesteatomas was confirmed by our observations in rats. The latex induced an acute and chronic inflammatory reaction when in contact with the mucosa of the middle ear.
胆脂瘤是一种复发性疾病，耳科医生难以控制。本研究旨在建立一种易于复制的胆脂瘤实验模型，使用乳胶诱导炎症反应，并将丙二醇作为中耳异物。
我们采用了一种新的实验模型，在大鼠鼓膜上故意穿孔，然后引入乳胶生物膜。
对照组仅进行鼓膜穿孔。实验组1使用丙二醇与乳胶，实验组2仅使用乳胶。在第八周处死大鼠，并用苏木精和伊红对其鼓泡进行染色。
实验组1中80%的动物和实验组2中90%的动物发生了胆脂瘤。对照组未形成胆脂瘤或炎性组织。
炎症细胞的存在可能会引发细胞因子（IL-1、IL-2、IL-6、IL-8）和生长因子的产生，这些因子与已知含有促进血管生长的蛋白质的乳胶生物膜一起，可能导致外耳道鳞状上皮向大鼠中耳的趋化性迁移，从而导致胆脂瘤。用乳胶和乳胶加50%丙二醇诱导大鼠实验性胆脂瘤是有效的，代表了一种优秀的实验模型。我们在大鼠中的观察结果证实了胆脂瘤发生过程中上皮迁移的理论。乳胶与中耳黏膜接触时会引发急性和慢性炎症反应。
