Perspectivas no tratamento da doença arterial coronária / Treatment perspectives for coronary artery disease

A despeito dos incontestáveis avanços no tratamento médico e em procedimentos de revascularização miocárdica (percutâneous e cirúrgicos), sintomas debilitantes relacionados à doença arterial coronária podem ocorrer devido à progressão da doença com envolvimento difuso arterial e oclusão de enxertos prévios ou reestenose pós-angioplastia, impossibilitando novos procedimentos de revascularização miocárdica. Característica desta condição (angina refratária) é o grande prejuízo dos afetados em termos de qualidade de vida, impedidos de realizar as atividades mais triviais do dia-a-dia (caminhar poucos metros no plano ou mesmo banha-se) sem que a dor anginosa ocorra; alguns pacientes são despertados frequentemente durante a noite por angina. Assim, para estes pacientes, o objetivo principal do tratamento é a melhoria na qualidade de vida, com maior tolerância ao esforço, e menor necessidade de hospitalizações e procedimentos diagnósticos ou terapêuticos. Neste contexto, elencaremos sucintamente as principais estratégias terapêuticas não farmacológica em desenvolvimento para o tratamento de pacientes com angina refratária, incluindo terapia gênica, terapia celular, revascularização transmiocárdica a laser, contrapulsação externa, estimulação de medula espinhal e revascularização miocárdica extracorpórea por ondas de choque.

Despite great advances in both medical management and myocardial revascularization procedures (percutaneous and surgical), disabling symptoms due to coronary artery disease may occur due to progression of the beds, grafts failures after successful bypass surgery, and/or stent restenosis, preventing further revacularization attempts. Patients with refractory angina have a mared impairment in quality of life, unable to perform any daily avtivity such as slowl walking or even taking a bath without chest pain; many patients are awaken during their sleep due to chest disconfort. For theses patients, the main objective f treatment is to improve their quality of life, with better exercise tolerance, and decreased number of hospitalizations and/or diagnosis/therapeutic procedures. In this paper, we briefly discuss new non-pharmacological therapeutic strategies being developed for patients with adavanced CAD including gene therapy, cell therapy, transmyocardial laser revascularization, enhanced external conter-pulsation, spinal cord stimulation and extracorporeal shockwave myocardial revascularization.

Células-tronco mesenquimais: caracterização, cultivo, propriedades imunológicas e aplicações clínicas / Mesenchymal stem cells: characterization, cultivation, immunological properties and clinical applications

As células-tronco mesenquimais (CTM) são consideradas células multipotentes não hematopoéticas com propriedades de autorrenovação e capacidade de diferenciação em tecidos mesenquimais e, possivelmente, em não mesenquimais. Vários estudos recentes têm reforçado o caráter multipotente destas células pela capacidade de diferenciarem-se em células derivadas da mesoderma embrionário: osteócitos, condroblastos e adipócitos. Devido ao fácil isolamento e cultivo, potencial de diferenciação e produção de fatores de crescimento e citocinas, as CTMs têm se tornado as candidatas ideais para os protocolos da medicina regenerativa. Este artigo revisa as principais características dessa célula, forma de obtenção e cultivo, propriedades imunológicas e aplicações clínicas.

Mesenchymal stem cells (MSC) are nonhematopoietic multipotent cells with selfrenewal properties and the ability to differentiate into mesenchymal tissues and possibly nonmesenchymal cells. Several lines of evidence in the past few years have confirmed the ability of these cells to differentiate into cells derived from embryonic mesoderm, such as osteocytes, adipocytes and chondroblasts. Because they are easy to isolate and culture and due to their differentiation potential and production of growth factors and cytokines, MSC have become ideal candidates for regenerative medicine protocols. This study reviews the main characteristics of MSC, how to isolate and culture them, and their immunological properties and clinical applications.

Potential applications of human embryonic stem cells.

Advances in reproductive technologies provided opportunity for scientists to be able to grow human embryos in vitro for more than two decades. Skills and knowledge derived from in vitro fertilization and in vitro culture of mammalian embryos opened the chance for scientists to develop the strategies to derive embryonic stem cell lines from mammalian and human embryos. This achievement has initiated a new era in the fields of biotechnology, pharmacology, basic scientific research, and cell-based medicine. To date, scientists have made some progress in optimizing regimens in deriving ES cell lines from human embryos but much more research and development are still required especially in the aspect of directing stem cells into the specific cells of potential clinical use. Collaboration among clinicians and scientists from diverse fields, together with the public awareness of how useful this technology could be to modern medicine, will result in the accumulation of knowledge in this field and, in the near future, a progress in cell-based therapy.

Cell therapy: hype or hope.

Cell therapy is a promising therapeutic tool for the next decade. It has a potential to cure a number of chronic diseases and conditions related to aging processes or degenerative changes. In addition, it could be used to replace cells and tissues in injured organs. Furthermore, it may provide a novel approach to congenital anomalies and genetic disorders where current therapeutic options are limited However, many crucial questions need answers to ensure a safe, effective and successful solution in the field of cell therapy. In Thailand, innovative knowledge and expertise in stem cell biology and technology are required as the key elements to make cell therapy a "real" hope.