Imobilização prolongada e remobilização da articulação fêmoro-tíbio-patelar de ratos: estudo clínico e microscópico / Experimental immobilization and remobilization rat knee joints: clinical and microscopic study

Trinta e quatro ratos foram alocados em quatro grupos experimentais: sem imobilização (G1), com imobilização do joelho direito por 45 dias (G2), com imobilização e remobilização com atividade livre por cinco semanas (G3), imobilização e remobilização com atividade livre e natação por cinco semanas (G4). A imobilização interferiu negativamente na marcha e amplitude articular e o G4 apresentou melhor evolução na marcha nos cinco primeiros dias, em relação ao G3. Após esse período, a evolução foi similar. Os componentes do G2 apresentaram rigidez articular, não observada em G3 e G4. Histologicamente, a imobilização promoveu aumento da espessura da cápsula articular, evidenciada pela presença do tecido conjuntivo fibroso que substituiu o tecido adiposo no G2, mas em menor proporção em G3 e G4. A imobilização determinou perda de proteoglicanos da matriz cartilaginosa, aumento do número de condrócitos, dispostos de forma irregular, aumento da espessura da cartilagem calcificada, irregularidade da superfície articular, proliferação de tecido conjuntivo no espaço intra-articular e aumento da espessura do osso subcondral. O G3 apresentou maior número de alterações na cartilagem e osso subcondral, quando comparado com G4. A imobilização degenerou as células sinoviais, indicando diminuição da produção de fluido sinovial e do suprimento nutricional à cartilagem. Tanto a atividade livre quanto sua associação com a natação favoreceram o retorno das condições biomecânicas e da cápsula articular, anteriores à imobilização.(AU)

Thirty-four rats were randomly allocated into one of four experimental groups: without immobilization (G1), immobilization of the right knee joint for 45 days (G2), immobilization and remobilization with free activity for 5 weeks (G3), and immobilization and remobilization with free activity and swimming program for 5 weeks (G4). The immobilization was prejudicial to march and flexibility articular. Animals from G4 showed a better march evolution on the first five days as compared to those from G3. After that periods, march evolution were similar in both G3 and G4. Animals from G2 showed rigid joint while in those from G3 and G4 the articular movement was close to normal. The histological analysis pointed out that immobilization led to increase in articular capsule thickness evidenced by the presence of fibrous connective tissue replacing adipose tissue in G2, but proportionally less in G3 and G4. It was observed that immobilization determined loss of proteoglycans from the cartilaginous matrix, increase in the number of regularly arranged condrocytes, increase in calcified cartilage thickness, irregularity in the articular surface, proliferation of connective tissue in the intra-articular space and increase in subchondral bone thickness. The animals from G3 showed a greater number of alterations in both articular cartilage and subchondral bone, as compared to those from G4. Immobilization degenerated synovial cells indicating decreased synovial fluid production and reduced nutritional supplying to the cartilage. The free cage activity and its association with swimming influenced positively the return of biomechanics and articular capsule morphologic conditions to those before immobilization.(AU)

Clinical and epidemiological characteristics of injuries caused by venomous snakes observed at the hospital for tropical diseases of Araguaína, Tocantins State, Brazil, from 1995 to 2000

Injuries caused by venomous snakes are considered a problem of public health in Brazil, and further studies for a better knowledge are very important. The aim of this work is to describe clinical and epidemiological characteristics that were observed from 1995 to 2000 in the Hospital for Tropical Diseases of Araguaína, Tocantins State, Brazil, which is a unit of health that takes care of patients suffering from tropical diseases. We studied 440 individuals and the most common characteristics observed were masculine sex, age among 15-45 years, bite in low members, and injuries caused by snakes of the Bothrops genus. The signs and symptoms more frequently observed were edema, pain, erythema, and bleeding. The most observed systemic manifestation was alteration of blood coagulation. The most frequent complications were abscess, necrosis, bacterial infection, and renal failure. The mortality rate was 3%. These data are very important for the evaluation of the problem.