ABSTRACT
INTRODUÇÃO: Não havendo um substituto valvar ideal, os homoenxertos criopreservados são considerados uma boa opção, pelo excelente perfil hemodinâmico, baixa incidência de tromboembolismo, resistência a infecções e durabilidade a médio prazo. Porém, estão sujeitos à progressiva degeneração, especialmente em crianças e adultos jovens. Sua antigenicidade desencadeia uma resposta imunológica que contribui para sua degeneração, calcificação e falência. Para diminuir esta antigenicidade, desenvolveu-se o processo de descelularização. Pela ação de detergentes e enzimas, este processo remove os componentes celulares do homoenxerto, diminuindo sua imunogenicidade e, provavelmente, retardando sua degeneração. OBJETIVO: O objetivo deste estudo, experimental e descritivo, é analisar o comportamento histológico e funcional de homoenxertos pulmonares ovinos descelularizados (H-descel) por uma nova solução, composta principalmente de dodecil sulfato de sódio a 0,1 por cento e desenvolvida na PUCPR. Para caracterizar este comportamento, serão avaliados o repovoamento celular, a ocorrência de calcificação e a função valvar ao ecocardiograma. MÉTODOS: A amostra foi constituída de oito ovinos, submetidos ao implante de H-descel em posição ortotópica, através de uma toracotomia esquerda, com auxílio de circulação extracorpórea. Os animais foram acompanhados clinicamente e por ecocardiogramas periódicos até o explante, realizados em prazos predefinidos para cada dois animais: sete, 30, 90 e 180 dias. A análise histológica foi realizada por colorações Hematoxilina-eosina, Pentacrômio de Movat e Alizarina Red. RESULTADOS: Todos os animais sobreviveram ao procedimento e atingiram seus períodos de seguimento. Não houve insuficiência ou estenose destes enxertos ao ecocardiograma. Os animais submetidos aos explantes em 90 e 180 dias tiveram significativos ganhos ponderais e estes H-descel aumentaram de diâmetro, sem desenvolver insuficiência. À histologia, todos mantiveram a organização de sua matriz extracelular, foram progressivamente repovoados e não apresentaram calcificação. CONCLUSÃO: Neste modelo experimental, os H-descel mostraram-se excelentes substitutos valvares a médio prazo.
INTRODUCTION: The cryopreserved homograft is a good valve substitute due attributes like excellent hemodynamics, low incidence of thromboembolic events, infection resistance and good mid-term durability. However, progressive homograft degeneration and fibrocalcification may occur, particularly in the childhood and young adults. Their antigenicity triggers an immunological reaction that plays an important role in their degeneration and failure. The decellularization process was proposed to decrease this antigenicity. By the action of detergents and enzymes, this process removes all cellular components from the homograft matrix, diminishing immunogenicity and probably delaying its degeneration. OBJECTIVE: The objective of this experimental and descriptive study is to evaluate the biological and functional behavior of decellularized pulmonary homografts (Decell-H), treated by a sodium dodecil sulfate solution (0.1 percent), developed in our University (Pontifícia Universidade Católica do Paraná). For the characterization of Decell-H performance, parameters like recellularization, calcification, and echocardiographic data will be analyzed. METHODS: Eight juvenile sheep were submitted to the implantation of the Decell-H sutured into orthotopic position, through a left thoracotomy and with cardiopulmonary bypass support. They were followed-up clinically and by periodical echocardiograms until the explantation, which were performed in different time for every two sheep: seven, 30, 90 and 180 postoperative days. For histological analysis we used Hematoxilin-eosin, Movat and Alizarin-Red staining. RESULTS: The sheep reached their follow-up period in a good clinical state. There was no valve regurgitation or stenonis by the echocardiogram. The animals submitted to the explantation in 90 and 180 days had a significant somatic growth and these Decell-H(s) had a diameter increase, without central valve insufficiency. Histologically, all homografts preserved their extra-cellular matrix organization and were progressively recellularized, without calcification. CONCLUSION: In this experimental model, the Decell-H behaved as an excellent valve substitute.
Subject(s)
Animals , Female , Male , Pulmonary Valve/transplantation , Sodium Dodecyl Sulfate/pharmacology , Surface-Active Agents/pharmacology , Tissue Engineering/methods , Echocardiography , Models, Animal , Pulmonary Valve/drug effects , Pulmonary Valve/pathology , Sheep , Transplantation, HomologousABSTRACT
Objective To study the immune protective effects of liver graft on intestinal graft in simultaneous liver/small bowel transplantation. Method Rat models(Wistar to SD) of liver/small bowel transplantation(LSBTx),single liver transplantation(LTx)and single small bowel transplantation(SBTx) were established respectively. Twelve recipients from each group were used to determine survival time. Six recipients from each group were sacrificed for liver and/or small bowel biopsy at posttransplantation day 5,7 and 14,respectively. Rejections were detected by histopathology and mRNA expression of IL-2,IL-4,perforin and granzyme B in grafts by semi-quantitative reverse transcript PCR. Result The survival time of LSBTx recipients was (27.83?4.47) d,much longer than SBTx recipients (11.58?3.26) d,but was similar to LTx recipients (28.92?2.39) d. Allograft rejections of intestinal graft in LSBTx group were milder than that in STBx group,accompanied by down-regulated mRNA expression of perforin and granzyme B. Conclusion Simultaneous liver/small bowel transplantation in rats provides immune protection on intestinal graft.
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Monocyte chemotactic peptide 1(MCP 1) is a specific chemotactic and activating factor for monocytes in acute renal transplant rejection. The present study was to diagnose aimed at diagnosing acute renal transplant rejection by determination of MCP 1 concentration in urine of kidney recipients by avidin biotin complex enzyme linked immunosorbent assay(ABC ELISA).Among the 65 recipients, the urinary MCP 1 concentration was (1278?64)pg/ml in 17 with acute rejection, which was higher than that in 40 clinically stable ones(511?16 pg/ml, P