基因治疗与心力衰竭

目的:探讨基因治疗方案的有效性和安全性。资料来源:应用计算机检索PUBMED1980-01/2006-10和EMCC 1994-10/2006-10与心力衰竭的基因治疗相关文章,检索词“Gen Therapy,Heart Failure”,并限定文章语言种类为“English”;同时计算机检索CMCC 1994-01/2006-10的相关文章,限定文章语言种类为中文,检索词“基因治疗、心力衰竭”。资料选择:对资料进行初审,选取试验包括上述治疗组和对照组的文献,然后筛除明显不随机临床试验的研究,对剩余的文献开始查找全文,进一步判断是否为RCT。纳入标准为:①试验包含平行对照组,即一般药物治疗。②治疗组为转基因治疗。资料提炼:共收集到49篇相关的随机和未随机试验,31个试验符合纳入标准。其余的排除。资料综合:31个试验包括478例动物模型,分别对应用不同靶点的转基因或基因敲除等方案进行治疗者予以评价。31篇文章中有10篇未达到预期的治疗目标,主要是在目的基因的选择及转染载体的选择方面出现了偏差。结论:虽动物试验取得了一定的成果,但尚无人体基因治疗的文献报道,随着基因技术的进步,基因治疗有望成为治疗心力衰竭的新途径。     

Results of intensive therapy in childhood acute myeloid leukemia, incorporating high-dose melphalan and autologous bone marrow transplantation in first complete remission

Childhood acute myeloid leukemia (AML) has a poor prognosis with standard chemotherapy. Allogeneic bone marrow transplantation (BMT) in remission improves the outlook only for the one third of patients with sibling donors. Autologous BMT with a lower morbidity and mortality is available to all. In this study, maximum cytoreduction was achieved by intensive early chemotherapy. Final intensification, with autologous BMT was offered to all those remaining in first complete remission (CR). Patients received two induction and two consolidation courses of intensively scheduled chemotherapy. Cytoreduction was assessed on day 14 and remission was assessed after courses 2 and 4. Bone marrow was harvested after recovery from the second consolidation course or after the first maintenance course and separated on a discontinuous percoll gradient before cryopreservation. Twenty-eight of 31 consecutively enrolled patients achieved CR. Three relapsed early and, of the 25 eligible, 24 underwent autologous BMT. Twenty-three patients received high-dose melphalan and 1 received busulphan and cyclophosphamide before autologous BMT at a median of 113 days (range, 86 to 301) after initial CR. Trilineage engraftment occurred in all. Neutrophil recovery to greater than 0.5 x 10(9)/L occurred at a median of 46 days (range, 13 to 92) after autologous BMT. Platelet recovery was delayed, with a median time to achieve greater than 20 x 10(9)/L of 42 days (range, 18 to 215). With a minimum follow up of 25 months following autologous BMT only 3 children have relapsed. The 5-year event-free survival rate (EFS) from diagnosis is 68% (95% confidence interval, 46% to 90%). Five- year EFS following autologous BMT is 87% (95% confidence interval, 67% to 100%). Autologous BMT with high-dose melphalan administration after intensive chemotherapy has produced EFS equivalent to allogeneic BMT and is associated with a strikingly low relapse rate. High-dose melphalan appears to be a valuable agent for conditioning therapy in AML.     

Enhanced fetal hemoglobin production by phenylacetate and 4- phenylbutyrate in erythroid precursors derived from normal donors and patients with sickle cell anemia and beta-thalassemia

In both sickle cell (SS) anemia and beta-thalassemia (beta-thal), an increase in fetal hemoglobin (HbF) ameliorates the clinical symptoms of the underlying disease. Several pharmacologic agents have been used to elevate HbF levels in adults; however, concerns regarding adverse effects of the prevailing drugs raise an urgent need for other agents capable of stimulating HbF production. We show here that sodium phenylacetate (NaPA) and its precursor, sodium 4-phenylbutyrate (NaPB), can enhance HbF production in cultured erythroid progenitor derived from normal donors and patients with SS anemia or beta-thal, when used at pharmacologic concentrations. Treatment resulted in (1) reduced cell proliferation, (2) elevated hemoglobin (Hb) content per cell (mean cellular Hb [MCH]), and (3) an increased proportion of HbF produced, associated with elevated levels of gamma-globin mRNA. Moreover, the active phenyl-fatty acids, with NaPA as a prototype, potentiated HbF induction by other drugs of clinical interest, including hydroxyurea (HU), sodium butyrate, and 5-azacytidine (5AzaC). Efficacy could be further enhanced by introducing chlorine substituents at the phenyl ring to increase drug lipophilicity. Our findings indicate that NaPA and NaPB, both already proven safe and effective in treatment of children with urea cycle disorders, might benefit also patients with severe hemoglobinopathies. The two-phase liquid culture procedure used in this study should prove valuable in further studies exploring the mechanisms of HbF induction by these agents, and might provide an assay to predict patient response in the clinical setting.