[Use of lyophilized cellulose in peripheral nerve lesions with loss of substance]. / Uso da celulose liofilizada em lesões de nervos periféricos com perda de substância.

Lyophilized cellulose was analysed to verify the degree of inflammatory reaction and axon realignment in the sciatic nerve after loss of neural substance. Ten mongrel dogs were divided into: Group 1 - 1 cm section of sciatic nerve which was replaced at lesion site; Group 2 nerve section without fragment replacement. The section site was involved with lyophilized cellulose. Group 3 -1 cm fragment section sutured epineurally. Motor response started at eighth week. Moderate fibrotic reaction to cellulose was seen in Group 1 and 2 animals. Groups 1 and 3 showed coaptation between the nerve and nerve graft with ongoing axons. In Group 2, 1 dog showed regrowth of axons through the empty space. It was concluded that lyophilized cellulose caused moderate fibrous reaction when implanted in peripheral nerve lesions with loss of substance; it can act as envelop protection in those lesions mainly if a neural graft is inserted.

[Probable Rasmussen's syndrome. Case report]. / Provável síndrome de Rasmussen. Relato de caso.

The syndrome of chronic encephalitis with epilepsy (Rasmussen's syndrome) typically occurs in children and is characterized by the development of intractable focal seizures, progressive hemiparesis and intellectual deterioration. The etiology is unknown, and the pathological abnormalities vary. We report the case of a 17-year-old boy, presenting with clinical features typical of probable Rasmussen's syndrome. We discuss the etiology and treatment for this pathology.

[Hemostatic and structural effects of the lyophilized cellulose sponge]. / Efeitos hemostático e estrutural da esponja de celulose liofilizada.

Hemostatic effects of oxidized cellulose (Surgicel) are well known. Based on a possible similar effect of a sponge obtained after lyophilization of biosynthetic cellulose, two different experimental studies were planned. Phase I-Pieces of cellulose sponge were inserted into small provoked cortical wounds of twelve dogs. The time elapsed to obtain bloodstill after cortical damage and application of cellulose was observed in every dog, searching to detect any possible hemostatic effect of the material. The animals were sacrificed after 7, 30 and 90 days. An average time of 1 minute was elapsed until bleeding control was achieved. No clinical adverse effect was noticed. Microscopy showed histiocytic and mild foreign body reaction at 7 days, which diminished at 30 days. Almost no reaction surrounded the implant at 90 days. Lyophilized cellulose has a peculiar eosinophilic appearance, composed by thin irregular filaments which diminished their thickness with the time. At 90 days only sparse irregular cellulose filaments could be detected. Phase II-Small equal sponge fragments were inserted in the liver of twelve rats and observed 7, 30 and 90 days. At autopsy, small peritoneal adhesions were noticed at 30 and 90 days. Microscopy showed intense histioplasmocytic and foreign body reaction in all animals mainly at 7 days. In two animals, refringent intracellular cellulose particles were evident inside giant foreign body cells after 90 days. This fact evidences that cellulose can be reabsorbed by phagocytic phenomena when implanted in mammalians. A comparative group with other hemostatic material and the same method must be done to clarify the issue of hemostatic effects of this membrane.