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BACKGROUND: Massive rotator cuff tears (MRCTs) are usually chronic lesions with pronounced degenerative changes, where advanced fatty degeneration and atrophy can make the tear irreparable. Human mesenchymal stem cells (hMSCs) secrete a range of growth factors and vesicular systems, known as secretome, that mediates regenerative processes in tissues undergoing degeneration. PURPOSE: To study the effect of hMSC secretome on muscular degenerative changes and shoulder function on a rat MRCT model. STUDY DESIGN: Controlled laboratory study. METHODS: A bilateral 2-tendon (supraspinatus and infraspinatus) section was performed to create an MRCT in a rat model. Forty-four Wistar-Han rats were randomly assigned to 6 groups: control group (sham surgery), lesion control group (MRCT), and 4 treated-lesion groups according to the site and periodicity of hMSC secretome injection: single local injection, multiple local injections, single systemic injection, and multiple systemic injections. Forelimb function was analyzed with the staircase test. Atrophy and fatty degeneration of the muscle were evaluated at 8 and 16 weeks after injury. A proteomic analysis was conducted to identify the molecules present in the hMSC secretome that can be associated with muscular degeneration prevention. RESULTS: When untreated for 8 weeks, the MRCT rats exhibited a significantly higher fat content (0.73% ± 0.19%) compared with rats treated with a single local injection (0.21% ± 0.04%; P < .01) or multiple systemic injections (0.25% ± 0.10%; P < .05) of hMSC secretome. At 16 weeks after injury, a protective effect of the secretome in the multiple systemic injections (0.62% ± 0.14%; P < .001), single local injection (0.76% ± 0.17%; P < .001), and multiple local injections (1.35% ± 0.21%; P < .05) was observed when compared with the untreated MRCT group (2.51% ± 0.42%). Regarding muscle atrophy, 8 weeks after injury, only the single local injection group (0.0993% ± 0.0036%) presented a significantly higher muscle mass than that of the untreated MRCT group (0.0794% ± 0.0047%; P < .05). Finally, the proteomic analysis revealed the presence of important proteins with muscle regeneration, namely, pigment epithelium-derived factor and follistatin. CONCLUSION: The study data suggest that hMSC secretome effectively decreases the fatty degeneration and atrophy of the rotator cuff muscles. CLINICAL RELEVANCE: We describe a new approach for decreasing the characteristic muscle degeneration associated with chronic rotator cuff tears. This strategy is particularly important for patients whose tendon healing after later surgical repair could be compromised by the progressing degenerative changes. In addition, both precise intramuscular local injection and multiple systemic secretome injections have been shown to be promising delivery forms for preventing muscle degeneration.
RESUMO
OBJECTIVO: Avaliar a sensibilidade da ecografia endorectal, em nossa experiência, no estadiamento do cancro do recto comparando com o resultado anatomopatológico. MATERIAL E MÉTODOS: Estudo retrospectivo, realizado entre Janeiro de 2005 e Agosto de 2009. Calculou-se a sensibilidade, a especificidade, o valor preditivo positivo e negativo para cada estadio T e N. Por meio da elaoração de curvas ROC avaliou-se a precisão do estadiamento ecoendoscópico e por meio do teste de McNemar comparou-se com o resultado anatomopatológico. RESULTADOS: Dos 112 doentes, 76 cumpriram os critérios de inclusão. Obtivemos uma eficácia de 75 a 97 por cento para uT e de 75 por cento para uN. Verificou-se sensibilidade, especificidade, valor preditivo positivo e negativo, respectivamente, de 63;98;92 e 89 por cento para uT1; 71;76;54 e 88 por cento para uT2; 67;81;73 e 76 por cento para uT3; 100;97;60 e 100 por cento para uT4; e 39;91;62 e 78 por cento para uN. As curvas ROC indicaram que a ecografia endorectal é um bom teste para o estadiamento do T e razoável para o N. O teste de McNemar revelou que não há diferenças significativas entre o estadiamento ecoendoscópico e anatomopatológico (p>0,05). CONCLUSÕES: Conclui-se que a ecografia endorectal é uma importante ferramenta no estadiamento do cancro do recto, apresentando boa correlação com o resultado anatomopatológico.
OBJECTIVE: This study aimed to evaluate endorectal ultrasound sensibility, in our experience, in rectal cancer staging comparing with pathologic result. METHODS: A retrospective study between January 2005 and August 2009. We calculated sensibility, specificity, positive and negative predictive value for T and N. Through ROC curves we evaluated endoscopic ultrasound accuracy and through McNemar test we compared it with the anatomopathological result. RESULTS: Of 112 patients, 76 met the inclusion criteria. We obtained an efficiency of 75 to 97 percent for uT and 75 percent in uN. There was a sensibility, specificity, positive and negative predictive value, respectively of 63, 98, 92 and 89 percent for uT1, 71 percent and 76, 54 and 88 for uT2, 67, 81; 73 and 76 percent for uT3, 100, 97, 60 and 100 percent uT4, and 39, 91, 62 and 78 percent for uN. The ROC curves indicated that endorectal ultrasound is a good test for T staging and reasonable for N staging. The McNemar test revealed no significant differences between endoscopic ultrasound and histological staging (p>0.05). CONCLUSIONS: We concluded that endorectal ultrasound is an important tool in rectal cancer staging, showing a good correlation with histopathological results.
