Morphologic characteristics of endometriosis in the mouse model: application to toxicology.

Surgically induced endometriosis in the mouse has been described as a model to investigate the effect of environmental pollutants on the growth of endometriotic implants. The objectives of this study were to evaluate a modified surgical procedure to induce endometriosis and validate the model by comparing the effects of estrogen, 4-chlorodiphenyl ether (4-CDE) as a possible estrogenic contaminant, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a contaminant with predominantly anti-estrogenic activities, on the growth of endometrial implants. Uterine strips (1.0 x 4.0 mm2) were autotransplanted to multiple sites in the abdomen of sexually mature female B6C3F1 mice (n = 33), which were randomly assigned to the following groups: intact control (n = 4); ovariectomized (OVX, n = 9); OVX and treated with 4-CDE (n = 6); OVX and treated with 17 beta-estradiol (E2, n = 9); and OVX and treated with E2 plus TCDD (n = 5). Endometrial implants survived warm ischemia regardless of implant site and appeared as small clear spherical or ovoid fluid-filled cysts. The diameter of the endometrial cysts in the OVX animals was significantly (p < 0.0001) smaller compared with the intact animals and OVX animals replaced with E2 or 4-CDE. In contrast, TCDD treatment inhibited the growth of endometrial cysts in the presence of estrogen. We conclude that autotransplantation of uterine slices to multiple abdominal sites results in formation of endometriotic cysts that are responsive to estrogen, and that environmental contaminants possess the potential to affect the survival and growth of endometrial cysts. Therefore, we concluded that the mouse endometriosis model described in this paper has applications to investigate the possible role of environmental pollutants in the development of endometriosis.

Partial replacement of the oesophageal muscle layers by a carbon-fibre prosthesis.

In the present study we report on the surgical replacement of the thoracic portion of oesophageal muscularis by a synthetic carbon fibre (CF) prothesis in a rabbit model. Our results, as corroborated by the oesophagograms and the post-operative weight gain, showed that this prothesis functioned satisfactorily for up to 6 weeks observation period. When the observation period was extended to 12 and 24 weeks after surgery, dilatation of the oesophagus at the prosthetic site was observed. All animals tolerated this dilatation and survived their intended observation period in good condition. In all these animals the body weight loss of -11.23 +/- 3.97% (p = 0.005) noted during the 1st week after the operation stopped and the body weight returned to its preoperative level within 3 weeks, as in the control groups. When the CF protheses were wrapped with a non-biodegradable polyurethane ether material with an elasticity of 19.2 g/mm, all rabbits died within 3 weeks or had to be sacrificed because of complications due to stagnation of food. In these rabbits the body weight decreased dramatically by -27.40 +/- 5.41% (p less than 0.001). In any similar future studies using the rabbit model, the post-operative body weight should provide a simple, sensitive and reliable monitoring tool for the functional assessment of the reconstructive procedure.