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Background: Postoperative epidural fibrosis (EF) after lumbar discectomy is the most common and at the same time controversial issue. Purpose: The etiology and pathogenesis creates a lot of discussion and selection of methods of treatment and prevention continues. Methods: LIV laminectomy with dura mater (DM) exposition was done in 24 rats, and then, 0.3 ml of elements of suspension of autologous intervertebral disk was implicated on DM. As autologous intervertebral disk, we used the intervertebral disk from amputated tail. In all the animals, incisions were closed with 3/0 Vicryl. EF was examined. Fibroblast cell density was calculated in each field at ×40 magnification: Grade 1 - fewer than 100 fibroblasts in each field; Grade 2 - 100-150 fibroblasts in each field; Grade 3 - more than 150 fibroblasts in each field. Results: Based on histological results, we confirmed our model of experiment. On the 30th day of evaluation, there were significant histological evidences of postoperative epidural adhesions in experimental animals, which included the obliteration of epidural space, the presence of adhesions in the dura and nerve roots, the restructuring of the yellow ligament, bone sclerosis, excessive appearance of fibrous tissue around the autologous intervertebral disk tissue that applied on the DM. Conclusion: In our work, we describe a new experimental model, where the elements of autologous intervertebral disk play the role of inflammation trigger, which cause postoperative scar and EF.

The population of Baikal seals Phoca sibirica has been plagued in 1987-88 by an unknown disease. Oligonucleotide probing of nucleic acids isolated from tissues of ill and dead animals, as well as immunological evidence and clinical data suggested that seals were infected by a morbillivirus. Morbillivirus antigen has been vizualized in dead seal tissues by immunoelectron microscopy (preembedding technique).The present report gives outline of electron microscopic studies of the tissues of infected Baikal seals. Morbillivirus antigens were vizualized as clusters of gold spheres by postembedding technique with monoclonal antibodies against measles virus and protein A-colloid gold conjugates in nuclei and cytoplasm of liver and kidney cells. Some clusters were associated with virus-like particles having a diameter of 80-100 nm. Electron microscopy of ultrathin sections stained with uranyl acetate revealed nucleocapsides having length of up to 1400 nm, and a diameter of 13-17 nm, morphologically similar to measles and seals distemper virus.