Early redox homeostasis disruption contributes to the differential cytotoxicity of imiquimod on transformed and normal endothelial cells.

The off-label use of imiquimod (IQ) for hemangioma treatment has shown clinical benefits. We have previously reported a selective direct IQ-cytotoxic effect on transformed (H5V) vs. normal (1G11) endothelial cells (EC). In the present study, we investigated the mechanism underlying this selective cytotoxicity in terms of TLR7/8 receptor expression, NF-κB signalling and time-dependent modifications of oxidative stress parameters (ROS: reactive oxygen species, catalase and superoxide dismutase activities, GSH/GSSG and lipid peroxidation). TLR7/8 level was extremely low in both cell lines, and IQ did not upregulate TLR7/8 expression or activate NF-κB signalling. IQ significantly induced ROS in H5V after 2 h and strongly affected antioxidant defenses. After 12 h, enzyme activities were restored to baseline levels but a robust drop in GSH/GSSG persisted together with increased lipid peroxidation levels and a marked mitochondrial dysfunction. Although in normal IQ-treated EC some oxidative stress parameters were affected after 4 h, mitochondrial health and GSH/GSSG ratio remained notably unaffected after 12 h. Therefore, the early alterations (0-2 h) in transformed EC breached redox homeostasis as strongly as to enhance their susceptibility to IQ. This interesting facet of IQ as redox disruptor could broaden its therapeutic potential for other skin malignancies, alone or in adjuvant schemes.

Update on the management and treatment of viral hepatitis.

This review aims to summarize the current evidence on the treatment of viral hepatitis, focusing on its clinical management. Also, future treatment options and areas of potential research interest are detailed. PubMed and Scopus databases were searched for primary studies published within the last ten years. Keywords included hepatitis A virus, hepatitis B virus (HBV), hepatitis C virus, hepatitis D virus (HDV), hepatitis E virus, and treatment. Outcomes reported in the studies were summarized, tabulated, and synthesized. Significant advances in viral hepatitis treatment were accomplished, such as the advent of curative therapies for hepatitis C and the development and improvement of hepatitis A, hepatitis B, and hepatitis E vaccination. Drugs that cure hepatitis B, going beyond viral suppression, are so far unavailable; however, targeted antiviral drugs against HBV (immunomodulatory therapies and gene silencing technologies) are promising approaches to eradicating the virus. Ultimately, high vaccination coverage and large-scale test-and-treat programmes with high screening rates may eliminate viral hepatitis and mitigate their burden on health systems. The development of curative hepatitis C treatment renewed the enthusiasm for curing hepatitis B, albeit further investigation is required. Novel therapeutic options targeting HDV life cycle are currently under clinical investigation.

Selective hemangioma cell dysfunction and apoptosis triggered by in vitro treatment with imiquimod.

Infantile hemangiomas are the most common benign tumors of infancy, characterized by unregulated angiogenesis and endothelial cells with high mitotic rate. Although spontaneous regression occurs, sometimes treatment is required and alternatives to corticosteroids should be considered to reduce side effects. Imiquimod is an imidazoquinoline, approved for some skin pathologies other than hemangioma. It is proposed that the effectiveness of imiquimod comes from the activation of immune cells at tumor microenvironment. However, the possibility to selectively kill different cell types and to directly impede angiogenesis has been scarcely explored in vitro for endothelial cells. In this work we showed a dramatic cytotoxicity on hemangioma cell, with a significant lower IC50 value in hemangioma compared to normal endothelial cells and melanoma (employed as a non-endothelial tumor cell line). Nuclear morphometric and flow-cytometry assays revealed imiquimod-induced apoptosis on hemangioma and melanoma cells but a small percentage of senescence on normal endothelial cells. At sub-lethal conditions, cell migration, a key step in angiogenesis turned out to be inhibited in a tumor-selective manner along with actin cytoskeleton disorganization on hemangioma cells. Altogether, these findings pointed out the selective cytotoxic effects of imiquimod on transformed endothelial cells, evidencing the potential for imiquimod to be a therapeutic alternative to reduce extensive superficial hemangioma lesions.

Intestinal and multivisceral transplantation.

Intestinal transplantation has shown exceptional growth over the past 10 years. At the end of the 1990's, intestinal transplantation moved out of the experimental realm to become a routine practice in treating patients with severe complications related to total parenteral nutrition and intestinal failure. In the last years, several centers reported an increasing improvement in survival outcomes (about 80%), during the first 12 months after surgery, but long-term survival is still a challenge. Several advances led to clinical application of transplants. Immunosuppression involved in intestinal and multivisceral transplantation was the biggest gain for this procedure in the past decade due to tacrolimus, and new inducing drugs, mono- and polyclonal anti-lymphocyte antibodies. Despite the advancement of rigid immunosuppression protocols, rejection is still very frequent in the first 12 months, and can result in long-term graft loss. The future of intestinal transplantation and multivisceral transplantation appears promising. The major challenge is early recognition of acute rejection in order to prevent graft loss, opportunistic infections associated to complications, post-transplant lymphoproliferative disease and graft versus host disease; and consequently, improve results in the long run.

Liver transplantation: history, outcomes and perspectives.

In 1958 Francis Moore described the orthotopic liver transplantation technique in dogs. In 1963, Starzl et al. performed the first liver transplantation. In the first five liver transplantations no patient survived more than 23 days. In 1967, stimulated by Calne who used antilymphocytic serum, Starzl began a successful series of liver transplantation. Until 1977, 200 liver transplantations were performed in the world. In that period, technical problems were overcome. Roy Calne, in 1979, used the first time cyclosporine in two patients who had undergone liver transplantation. In 1989, Starzl et al. reported a series of 1,179 consecutives patients who underwent liver transplantation and reported a survival rate between one and five years of 73% and 64%, respectively. Finally, in 1990, Starzl et al. reported successful use of tacrolimus in patents undergoing liver transplantation and who had rejection despite receiving conventional immunosuppressive treatment. Liver Transplantation Program was initiated at Hospital Israelita Albert Einstein in 1990 and so far over 1,400 transplants have been done. In 2013, 102 deceased donors liver transplantations were performed. The main indications for transplantation were hepatocellular carcinoma (38%), hepatitis C virus (33.3%) and alcohol liver cirrhosis (19.6%). Of these, 36% of patients who underwent transplantation showed biological MELD score > 30. Patient and graft survival in the first year was, 82.4% and 74.8%, respectively. A major challenge in liver transplantation field is the insufficient number of donors compared with the growing demand of transplant candidates. Thus, we emphasize that appropriated donor/receptor selection, allocation and organ preservation topics should contribute to improve the number and outcomes in liver transplantation.

Liver transplantation: history, outcomes and perspectives / Transplante de fígado: história, resultados e perspectivas

In 1958 Francis Moore described the orthotopic liver transplantation technique in dogs. In 1963, Starzl et al. performed the first liver transplantation. In the first five liver transplantations no patient survived more than 23 days. In 1967, stimulated by Calne who used antilymphocytic serum, Starzl began a successful series of liver transplantation. Until 1977, 200 liver transplantations were performed in the world. In that period, technical problems were overcome. Roy Calne, in 1979, used the first time cyclosporine in two patients who had undergone liver transplantation. In 1989, Starzl et al. reported a series of 1,179 consecutives patients who underwent liver transplantation and reported a survival rate between one and five years of 73% and 64%, respectively. Finally, in 1990, Starzl et al. reported successful use of tacrolimus in patents undergoing liver transplantation and who had rejection despite receiving conventional immunosuppressive treatment. Liver Transplantation Program was initiated at Hospital Israelita Albert Einstein in 1990 and so far over 1,400 transplants have been done. In 2013, 102 deceased donors liver transplantations were performed. The main indications for transplantation were hepatocellular carcinoma (38%), hepatitis C virus (33.3%) and alcohol liver cirrhosis (19.6%). Of these, 36% of patients who underwent transplantation showed biological MELD score > 30. Patient and graft survival in the first year was, 82.4% and 74.8%, respectively. A major challenge in liver transplantation field is the insufficient number of donors compared with the growing demand of transplant candidates. Thus, we emphasize that appropriated donor/receptor selection, allocation and organ preservation topics should contribute to improve the number and outcomes in liver transplantation.

Em 1958, Francis Moore descreveu a técnica do transplante de fígado em cães. Em 1963, Starzl e sua equipe realizaram o primeiro transplante de fígado. Nos primeiros cinco transplante de fígado, nenhum paciente sobreviveu mais que 23 dias. Até 1977, aproximadamente 200 transplante de fígado tinham sido realizados no mundo. Neste período, foi estabelecida a solução de problemas técnicos do transplante de fígado. Calne, em 1979, utilizou, pela primeira vez, a ciclosporina em dois pacientes submetidos ao transplante de fígado. Starzl e seus colaboradores relataram, já em 1989, que a sobrevida de 1.179 pacientes submetidos ao transplante de fígado em 1 e 5 anos foi, respectivamente, de 73 e 64%. Finalmente, em 1990, Starzl relatou o primeiro uso do novo imunossupressor tacrolimo em pacientes de transplante de fígado que apresentavam rejeição mesmo com o tratamento imunossupressor convencional. O transplante de fígado iniciou-se no Hospital Israelita Albert Einstein em 1990 e já foram realizados mais de 1.400 transplantes. Em 2013, foram realizados 102 transplantes de fígado de doadores falecidos. As principais indicações para o transplante foram carcinoma hepatocelular (38%), cirrose hepática secundária ao vírus C (33,3%) e cirrose alcoólica (19,6%). Destes, 36% dos transplantes apresentavam MELD biológico superior a 30. As sobrevidas do paciente e do enxerto no primeiro ano foram, respectivamente, 82,4 e 74,8%. Um dos maiores desafios da área do transplante de fígado é o número insuficiente de doadores para uma demanda crescente de candidatos ao procedimento. Dessa forma, destacamos que tópicos relacionados à seleção de doadores/receptores, alocação e preservação de órgãos devem contribuir para o aumento e a melhora dos resultados do transplante de fígado.

Intestinal and multivisceral transplantation / Transplante intestinal e multivisceral

Intestinal transplantation has shown exceptional growth over the past 10 years. At the end of the 1990’s, intestinal transplantation moved out of the experimental realm to become a routine practice in treating patients with severe complications related to total parenteral nutrition and intestinal failure. In the last years, several centers reported an increasing improvement in survival outcomes (about 80%), during the first 12 months after surgery, but long-term survival is still a challenge. Several advances led to clinical application of transplants. Immunosuppression involved in intestinal and multivisceral transplantation was the biggest gain for this procedure in the past decade due to tacrolimus, and new inducing drugs, mono- and polyclonal anti-lymphocyte antibodies. Despite the advancement of rigid immunosuppression protocols, rejection is still very frequent in the first 12 months, and can result in long-term graft loss. The future of intestinal transplantation and multivisceral transplantation appears promising. The major challenge is early recognition of acute rejection in order to prevent graft loss, opportunistic infections associated to complications, post-transplant lymphoproliferative disease and graft versus host disease; and consequently, improve results in the long run.

O transplante de intestino, ao redor do mundo, tem crescido de maneira sólida e consistente nos últimos 10 anos. No final da década de 1990, passou de um modelo experimental para uma prática clínica rotineira no tratamento dos pacientes com complicação severa da nutrição parenteral total com falência intestinal. Nos últimos anos, vários centros têm relatado uma crescente melhora nos resultados de sobrevida do transplante no primeiro ano (ao redor de 80%), porém, a longo prazo, ainda é desafiador. Diversos avanços permitiram sua aplicação clínica. O surgimento de novas drogas imunossupressoras, como o tacrolimus, além das drogas indutoras, os anticorpos antilinfocíticos mono e policlonal, nos últimos 10 anos, foi de suma importância para a melhora da sobrevida do transplante de intestino/multivisceral, mas, apesar dos protocolos bastante rígidos de imunossupressão, a rejeição é bastante frequente, podendo levar a altas taxas de perdas de enxerto a longo prazo. O futuro do transplante de intestino e multivisceral parece promissor. O grande desafio é reconhecer precocemente os casos de rejeição, prevenindo a perda do enxerto e melhorando os resultados a longo prazo, além das complicações causadas por infecções oportunistas, doenças linfoproliferativas pós-transplante e a doença do enxerto contra hospedeiro.