重组人促红细胞生成素诱发慢性肾功能衰竭大鼠高血压的机制以及波生坦的干预作用

目的探讨内皮素受体拮抗剂波生坦对重组人促红细胞生成素(rHuEPO)诱发肾大部切除大鼠高血压的干预作用及可能机制。方法采用分阶段5/6肾切除术制备大鼠慢性肾功能衰竭动物模型。实验动物随机分为4组:Ⅰ组假手术组,Ⅱ组肾大部切除组(SNX),Ⅲ组肾大部切除加EPO组(SNX+EPO),Ⅳ组肾大部切除加EPO加波生坦组(SNX+EPO+波生坦)。观察各组大鼠红细胞压积、血肌酐、血压及血浆和肾皮质内皮素(ET-1)水平的变化。结果rHuEPO不仅可显著提高慢性肾功能衰竭大鼠的红细胞压积,并可诱发其血压升高,同时显著升高血浆及肾皮质ET-1水平(P<0.05)。rHuEPO诱导的血压升高与ET-1呈正相关关系(P<0.05);而波生坦则可明显降低由rHuEPO诱发的高血压水平,且可降低血肌酐水平,肾组织ET-1含量亦显著下降(P<0.05)。结论波生坦可明显干预由rHuEPO治疗慢性肾功能衰竭贫血所诱导的血压升高,提示rHuEPO和波生坦的效应可能是由内皮素机制所介导。     

Potential long-term inhibition of ocular neovascularisation by recombinant adeno-associated virus-mediated secretion gene therapy

Neovascularisation (NV) within the eye often results in visual loss. Vascular endothelial growth factor (VEGF) has been implicated in the development of ocular NV. Previous studies have shown that VEGF antagonists successfully suppressed retinal and choroidal NV in animal models. However, the systemic approach and transient nature of the delivery systems used in these studies hinder therapeutic application. To achieve stable and localised ocular anti-angiogenic therapy, we explored the use of recombinant adeno-associated virus (rAAV)-mediated secretion gene therapy (SGT). In this study, we generated a rAAV vector encoding soluble VEGF receptor 1, sFlt-1 (AAV-CMV.sflt) and determined its ability to inhibit cautery-induced corneal NV and laser-induced choroidal NV. Delivery of AAV-CMV.sflt into the anterior chamber resulted in transgene expression in the iris pigment epithelium and corneal endothelium, which reduced the development of corneal NV in the stroma of cauterised rats by 36% compared with cauterised control groups (P = 0.009). Subretinal delivery of AAV-CMV.sflt near the equator of the eye also suppressed choroidal NV at the laser lesions around the optic nerve by 19% (P = 0.002), indicating that there was diffusion of the secreted anti-angiogenic protein across the retina. Both results suggest that the long-term suppression of ocular NV is possible through the use of stable rAAV-mediated SGT.     

基因转导技术治疗心力衰竭的研究进展

慢性心力衰竭（CHF）是构成全球人口发病率和病死率的主要原因,无论在经济方面还是社会方面都给人类带来了巨大的负担。目前,虽然常规治疗方法在降低心力衰竭病死率方面有着稳定和实质性的进展,但是新的药物以及常规心脏外科手术在延长5年生存率方面并没有取得满意的临床效果。基因治疗是在上世纪70年代随着重组DNA技术的发展而引入的。幸运的是,近年来随着基于载体的基因转导策略在动物模型以及初步临床试验中的应用,基因治疗可能会为CHF提供理想的替代治疗方案。20年来,研究者针对心力衰竭基因治疗的不同基因,不同信号转导通路和不同转导方式进行了大量研究。目前CHF基因治疗的主要目的是抑制心肌细胞凋亡,并通过最有效的心肌转染减少不良重塑和增加收缩力。在本文中,将总结多种心力衰竭模型中的基因转导技术,讨论这些转导策略在基于载体介导的心脏基因转导系统中的优势和不足,并着重论述基于外科方法的再循环转导技术。     

腺相关病毒介导癌胚抗原转染树突状细胞对免疫功能的调节作用

目的:近年来,树突状细胞参与调节作用的研究较多。实验拟验证重组腺相关病毒(rAAV)介导癌胚抗原基因转染树突状细胞后其的免疫调节作用的变化。方法:实验于2006-06/2006-11在美国阿肯色大学医学院基因治疗中心完成。①实验方法:取健康人外周血(自愿捐献),采用改良Ficoll密度梯度离心的方法分离外周血单个核细胞,取贴壁细胞,分为rAAV/CEA转染组和空白对照组,均采用重组人粒细胞巨噬细胞集落刺激因子、白细胞介素4、肿瘤坏死因子-α诱导树突状细胞前体细胞成熟,将成熟树突状细胞与末梢血淋巴细胞按比例混合培养,可得到激活的细胞毒性T淋巴细胞。②实验评估:采用流式细胞仪检测树突状细胞表面标志表达,细胞毒性T淋巴细胞的免疫表型变化,细胞毒性T淋巴细胞γ-干扰素表达。采用酶联免疫吸附法(ELISA法)检测树突状细胞的白细胞介素12和白细胞介素10表达。结果:①rAAV/CEA转染树突状细胞的CD14较空白对照组降低,共刺激分子CD40、CD80、CD83、CD86表达均较空白对照组高。②成熟树突状细胞细胞因子表达中,rAAV/CEA转染组的白细胞介素12较空白对照组升高,白细胞介素10降低。③与空白对照组比较,rAAV/CEA转染组能高表达CD8 T细胞和其表型CD69,CD8/CD56的T细胞比例上调,CD25 CD4 的T细胞减少。④rAAV/CEA转染的细胞毒性T淋巴细胞表达相对较高水平的γ-干扰素,与杀伤实验结果相吻合。结论:rAAV/CEA转染树突状细胞能够激活细胞毒性T淋巴细胞的特异性杀伤作用,与树突状细胞和细胞毒性T淋巴细胞等免疫细胞表面标志变化和细胞内细胞因子水平变化相关。     

LAK免疫支持治疗对慢性肾功能衰竭大鼠残余肾功能的影响

目的 研究 LAK(Lymphokine-activated killer cells)免疫支持治疗对大鼠慢性肾功能衰竭(Chr-onic renal failure,CRF)肾功能的影响,以评估该治疗在CRF临床治疗中的应用前景。方法 对SD大鼠采用两步法行5/6肾脏切除术建立CRF动物模型,并制备LAK,在此基础上分别对CRF大鼠进行LAK治疗与生理盐水对照处理;对大鼠肾切术前后及LAK治疗后3周、6周血尿毒氮(BUN)、肌酐(Cr)进行测定,并应用酶联免疫吸附试验(ELISA)测定血浆白细胞介素-1β(IL-1β)水平来反映CRF肾脏慢性纤维化。结果 5/6肾脏切除术后,大鼠BUN,Cr及血浆IL-1β水平较显著升高(P<0.01);LAK治疗后3周、6周,BUN、Cr及血浆IL-1β水平较同期生理盐水对照处理组大鼠显著降低(P<0.01);结论 LAK可能通过改善机体免疫状态,减少血液循环中某些细胞因子(如IL-1)异常升高,最终延缓肾小球及肾间质慢性纤维化的病理进程及并行的残余肾功能进行性破坏;LAK作为一种过继性细胞免疫支持治疗,可能在今后的CRF患者支持治疗中有着相当的临床应用前景。     

慢性肾功能衰竭的饮食治疗

INTRODUCTION In the current paper,effect of diet therapy on chronic renal failure(CRF) was reviewed.     

Mesenchymal stem cell therapy for chronic renal failure

Importance of the field: Chronic kidney disease (CKD) has become a worldwide public health problem. Renal transplantation is the treatment of choice for end-stage renal disease, but is limited by a small number of organ donors and the immune barrier. To overcome these problems, new therapeutic strategies for tissue repair have recently emerged.

Areas covered in this review: We discuss the therapeutic potential of mesenchymal stem cells (MSCs) in kidney injury and examine the latest reports providing evidence supporting MSC efficacy in the treatment of chronic renal failure (CRF).

What the reader will gain: MSCs improve histological and functional outcomes in various CRF model systems. Paracrine effects rather than transdifferentiation might result in the prevention of progressive renal failure. In addition, MSCs can reprogram kidney cell differentiation, and modulate neo-kidney transplantation in CRF.

Take home message: Although many practical problems remain to be addressed, treatment with MSCs will enter the mainstream of CRF treatment.     

A histone deacetylase inhibitor enhances recombinant adeno-associated virus-mediated gene expression in tumor cells.

The transduction of cancer cells using recombinant adeno-associated virus (rAAV) occurs with low efficiency, which limits its utility in cancer gene therapy. We have previously sought to enhance rAAV-mediated transduction of cancer cells by applying DNA-damaging stresses. In this study, we examined the effects of the histone deacetylase inhibitor FR901228 on tumor transduction mediated by rAAV types 2 and 5. FR901228 treatment significantly improved the expression of the transgene in four cancer cell lines. The cell surface levels of alpha v integrin, FGF-R1, and PDGF-R were modestly enhanced by the presence of FR901228. These results suggest that the superior transduction induced by the HDAC inhibitor was due to an enhancement of transgene expression rather than increased viral entry. Furthermore, we characterized the association of the acetylated histone H3 in the episomal AAV vector genome by using the chromatin immunoprecipitation assay. The results suggest that the superior transduction may be related to the proposed histone-associated chromatin form of the rAAV concatemer in transduced cells. In the analysis with subcutaneous tumor models, strong enhancement of the transgene expression as well as therapeutic effect was confirmed in vivo. The use of this HDAC inhibitor may enhance the utility of rAAV-mediated transduction strategies for cancer gene therapy.     

Minoxidil therapy for refractory hypertension and chronic renal failure

Minoxidil, a potent vasodilator antihypertensive agent, was given to 14 patients with severe hypertension uncontrolled by conventional agents. Thirteen patients had elevated serum creatinine levels. Over a period of 20 months (mean duration of administration) minoxidil lowered blood pressure from 194/124 to 147/90 mm Hg (mean values), in combination with furosemide and a sympathetic inhibitor (usually propranolol). Progression of preexisting renal disease was halted in all but three patients. Fluid retention, cardiac failure, and angina were troublesome side effects. The occurrence of hypertrichosis also limited the usefulness of minoxidil, particularly in female patients.     

Tertatolol ameliorates renal function in rats with chronic renal failure

Tertatolol is a new beta-blocking agent which induces renal vasodilation in experimental animals and humans and increases glomerular filtration rate (GFR), diuresis and natriuresis. The mechanisms underlying renal effects of tertatolol are not known. Our aims were to establish whether tertatolol influences renal function by a systemic or by an intrarenal effect and to assess whether tertatolol could maintain GFR in chronic renal failure. Tertatolol but not propranolol when given as i.v. bolus injection at the dose of 25 and 50 micrograms/kg. b.w. induces a significant increase in GFR and perfusate flow rate (PFR) in an isolated perfused kidney model [GFR: tertatolol, 25 micrograms/kg; preinjection: 0.477 +/- 0.077 ml/min/g of kidney; 30 min postinjection: 0.996 +/- 0.114 ml/min/g of kidney. Tertatolol (50 micrograms/kg) preinjection: 0.517 +/- 0.040 ml/min/g of kidney; 30 min postinjection: 0.879 +/- 0.035 ml/min/g of kidney. Propranolol (500 micrograms/kg) preinjection: 0.574 +/- 0.045 ml/min/g of kidney; 30 min postinjection: 0.538 +/- 0.029 ml/min/g of kidney. PFR: tertatolol, 25 micrograms/kg, preinjection: 30.00 +/- 0.79 ml/min; 30 min postinjection: 36.20 +/- 2.58 ml/min. Tertatolol (50 micrograms/kg) preinjection: 29.30 +/- 1.44 ml/min; 30 min postinjection: 38.01 +/- 1.87 ml/min. Propranolol (500 micrograms/kg) preinjection: 28.70 +/- 1.04 ml/min; 30 min postinjection: 28.30 +/- 0.91 ml/min]. In the same preparation tertatolol significantly increases urine flow rate and Na+ excretion [urine flow rate: tertatolol (25 micrograms/kg) preinjection: 28.28 +/- 4.10 microliter/min; 60 min postinjection: 38.23 +/- 6.74 microliter/min. Tertatolol (50 micrograms/kg) preinjection: 24.02 +/- 0.63 microliter/min; 60 min postinjection: 33.18 +/- 2.07 microliter/min.(ABSTRACT TRUNCATED AT 250 WORDS)     

Elastin-like polypeptide matrices for enhancing adeno-associated virus-mediated gene delivery to human neural stem cells

The successful development of efficient and safe gene delivery vectors continues to be a major obstacle to gene delivery in stem cells. In this study, we have developed an elastin-like polypeptide (ELP)-mediated adeno-associated virus (AAV) delivery system for transducing fibroblasts and human neural stem cells (hNSCs). AAVs have significant promise as therapeutic vectors because of their safety and potential for use in gene targeting in stem cell research. ELP has been recently employed as a biologically inspired 'smart' biomaterial that exhibits an inverse temperature phase transition, thereby demonstrating promise as a novel drug carrier. The ELP that was investigated in this study was composed of a repetitive penta-peptide with [Val-Pro-Gly-Val-Gly]. A novel AAV variant, AAV r3.45, which was previously engineered by directed evolution to enhance transduction in rat NSCs, was nonspecifically immobilized onto ELPs that were adsorbed beforehand on a tissue culture polystyrene surface (TCPS). The presence of different ELP quantities on the TCPS led to variations in surface morphology, roughness and wettability, which were ultimately key factors in the modulation of cellular transduction. Importantly, with substantially reduced viral quantities compared with bolus delivery, ELP-mediated AAV delivery significantly enhanced delivery efficiency in fibroblasts and hNSCs, which have great potential for use in tissue engineering applications and neurodegenerative disorder treatments, respectively. The enhancement of cellular transduction in stem cells, as well as the feasibility of ELPs for utilization in three-dimensional scaffolds, will contribute to the advancement of gene therapy for stem cell research and tissue regenerative medicine.     

Immunoreactive tissue kallikrein in human serum

Human urinary kallikrein and an antiserum to it raised in the rabbit were used to detect and quantitate immunoreactive tissue kallikrein in human serum. Both 125I-labeled kallikrein and the unlabeled purified enzyme appear complexed to higher molecular weight entities in serum, but specific binding between radiolabeled enzyme and antiserum was unaffected by the presence of serum or plasma. Parallelism to standard displacement curves was always seen with radioimmunoassay of normal sera as well as with human mixed saliva or pancreatic extracts. Assay sensitivity is 160 pg/ml of serum, or 16 pg per tube. Purified plasma kallikrein or prekallikrein in concentrations up to 10 micrograms/ml showed no displacement. Acetone-kaolin activation of plasma produced the expected 30-fold increase in Tos-Arg-OMe esterase activity but no change in immunoreactive tissue kallikrein levels. Serum concentrations were 3.8 +/- 0.7 (mean +/- SE) ng/ml in 21 normal volunteers, and were similar in patients with Fletcher trait or Hageman factor deficiency. Significantly increased serum concentrations were seen with long-term low dietary sodium intake or acute forms of pancreatitis. Although the relation of this immunoreactive material to any active tissue kallikrein within the circulation remains to be determined, our studies provide a new parameter for the assessment of a system repeatedly suggested to have some role in regulation of vascular resistance.     

Dialytic therapy in the management of chronic renal failure

The maintenance of life after the development of end-stage renal disease can be achieved by the use of dialytic therapy, either alone as permanent replacement therapy or in conjunction with transplantation. The imperfections of all forms of dialytic therapy leave the nephrologist with the responsibility of recommending to the patient the treatment(s) considered most suitable. Hemodialysis, hemofiltration, and peritoneal dialysis are discussed in this article.     

慢性肾衰竭病人的饮食治疗进展

综述了饮食治疗慢性肾功能不全(CRF)的原理和作用、不同阶段CRF病人饮食治疗的措施、饮食治疗的效果判断及监测;提出饮食治疗可改善病人的营养状况,提高病人的生活质量。     

慢性肾衰竭病人的饮食治疗进展

综述了饮食治疗慢性肾功能不全（CRF）的原理和作用、不同阶段CRF病人饮食治疗的措施、饮食治疗的效果判断及监测;提出饮食治疗可改善病人的营养状况,提高病人的生活质量。