Bone marrow-derived mononuclear cell therapy for patients with ischemic heart disease and ischemic heart failure

Objective: This meta-analysis aimed to assess whether bone marrow-derived mononuclear cells (BMMNCs) therapy may improve cardiac functional parameters in patients with ischemic heart disease (IHD) or ischemic heart failure (IHF).

Methods: Relevant randomized controlled trials (RCTs) were searched from web databases. Weighted mean difference was calculated for changes in left ventricular ejection fraction (LVEF), left ventricular end-diastolic and end-systolic volumes by using a random effects model.

Results: 13 RCTs met inclusion criteria. Compared with controls, BMMNCs therapy improved LVEF by 3.83% (95% confidence interval (CI): 2.10 – 5.56%; p < 0.0001) in patients with ischemic heart conditions. Notably, in patients with IHF, a more severe clinical condition when compared with IHD, BMMNCs therapy appeared more effective in LVEF improvement. While LVEF increased by 5.67% (95% CI: 3.65 – 7.69%; p < 0.00001) in IHF patients, it only increased by 2.19% (95% CI: 0.37 – 4.00%; p = 0.02) in patients with IHD.

Conclusions: BMMNCs therapy is associated with moderate but significant improvement over regular therapy in LVEF in patients with IHD and IHF. This observation, therefore, supports further RCTs conducting safety and efficiency of BMMNCs therapy with longer-term follow-up.     

Impact of intracoronary reinfusion of bone marrow-derived mononuclear progenitor cells on cardiopulmonary exercise capacity in patients with chronic postinfarction heart failure

Introduction

Intracoronary infusion of bone marrow-derived progenitor cells (BMC) in patients with chronic ischaemic heart failure (CHF) is associated with improvement in left ventricular ejection fraction (LVEF), reduction of NT-proBNP levels and improved prognosis. However, effects of this therapy on cardiopulmonary exercise capacity have not been investigated separately so far.

Patients and methods

One hundred and fifty-four patients with ischaemic heart failure (mean LVEF 40.3 ± 10.9 %, NT-proBNP 1,103 ± 1,436 pg/ml) underwent cardiopulmonary exercise capacity testing (CPX) before and 3 months after intracoronary infusion of autologous BMC. Thirty patients with a potential bias on the CPX course as concomitant coronary intervention, bypass surgery, new onset of arrhythmias or implantation of cardiac resynchronization devices were excluded from further analysis.

Results

The remaining 124 patients showed an increase in exercise time and peak workload by 16.8 and 6 %. Peak oxygen uptake and oxygen uptake efficiency slope also improved by 2.9 and 12.9 %, whereas other parameters like peak oxygen pulse and the slope of minute ventilation versus CO₂ elimination remained unchanged. Analysis of patients with poor, moderate and conserved CPX results prior to cell therapy documented that patients in tertiles with lowest initial exercise capacity showed the largest improvements in CPX after therapy. The differences in response to cell therapy were detectable in all investigated CPX parameters and became significant for exercise time, peak oxygen uptake and peak oxygen pulse.

Summary

These findings indicate that intracoronary BMC therapy improves exercise capacity in CHF patients with more advanced heart failure.     

自体骨髓单核细胞移植治疗终末期缺血性心力衰竭病人的护理

近年来,随着急性心肌梗死早期存活率的提高,后期进入到因心肌细胞坏死、梗死心肌瘢痕形成、室壁变薄、室腔扩大的心室重构过程,以致最终发展为缺血性心力衰竭的病人呈逐年增加趋势[1,2]。部分病人发展为药物治疗无效,外科手术、内科介入不能耐受,长期或反复住院,甚至靠静脉输入     

经皮冠状动脉自体骨髓单个核细胞移植对重症心力衰竭患者心功能的影响

目的:观察自体骨髓单个核细胞经皮冠状动脉移植治疗重症心力衰竭的效果,探讨其可行性、安全性和有效性。方法:选取2006-02/08承德北方医院收治的20例重症心力衰竭患者,男14例,女6例,平均年龄(54±13)岁,由家属签署手术同意书。①患者俯卧位局麻,双测髂后上嵴行多点穿刺,抽取骨髓血60～260mL,要求在60min内完成。将采集的骨髓血进行骨髓细胞分离、洗涤,用生理盐水稀释单个核细胞悬液至20～30mL。②用PTCA球囊以先后顺序放置在左前降支中段或右冠状动脉中段,以4～6个大气压扩张球囊临时阻断远端血流,从球囊导管尾端注入分离净化的骨髓单个核细胞,左冠状动脉注射总量2/3,右冠状动脉注射总量1/3。③分别于术后1,3个月进行随访,检测NYHA心功能分级与射血分数,以6min标准步行实验评估运动能力。结果:实验选取20例重症心力衰竭患者,3例于术前发生猝死而退出试验,最终17例成功进行自体骨髓细胞移植,均完成术后3个月随访。①自体骨髓单个核细胞移植过程中的不良反应:17例患者中,严重心律失常1例,急性左心室衰竭1例,心绞痛2例,头痛1例,术中呕吐2例,术后低热1例,穿刺点血肿1例。②自体骨髓单个核细胞移植后不同时间NYHA心功能分级的变化:与术前比较,自体骨髓单个核细胞移植术后1,3个月NYHA心功能分级均明显提高(t=9.294～10.102,P均<0.01)。③自体骨髓单个核细胞移植后不同时间心功能指标与运动能力的变化:与术前比较,自体骨髓单个核细胞移植术后1,3个月NYHA心功能分级、左心室射血分数、左心室舒张末期直径、6min行走距离均得到明显改善(t=3.034～5.064,P<0.05)。④NYHA心功能改善程度与其他心功能参数的相关性:细胞移植后3个月,NYHA心功能分级改善程度与左心室射血分数、左心室舒张末期直径呈明显正相关(r=0.461～0.494,P均<0.05)。结论:经皮冠状动脉移植自体骨髓单个核细胞,可明显改善重症心力衰竭患者心功能及运动能力,安全可行。     

骨髓间充质样干细胞和骨髓单个核细胞影响博莱霉素诱导肺纤维化的比较

背景:有报道指出,骨髓间充质样干细胞和骨髓单个核细胞在多种疾病中被证明有疗效,骨髓间充质样干细胞在肺纤维化模型中也有应用.目的:比较骨髓间充质样干细胞和骨髓单个核细胞对博莱霉素A5所致大鼠肺泡炎和早期纤维化的治疗作用.方法:收集Wistar雄性幼鼠的骨髓间充质样干细胞、骨髓单个核细胞并分别进行DAPI标记.21只Wistar雌性大鼠气管内注入博莱霉素A5制作肺损伤模型,随机均分为骨髓间充质样干细胞治疗组、骨髓单个核细胞治疗组和模型组.造模后第7天处死大鼠,取肺组织病理切片观察炎症和纤维化情况;荧光显微镜下检测DAPI标记细胞;ELISA法检测肺组织匀浆羟脯氨酸和肿瘤坏死因子的含量.结果与结论:①在骨髓间充质样干细胞治疗组、骨髓单个核细胞治疗组肺组织冰冻切片中均见到DAPI标记的外源细胞.②模型组肺泡炎最严重,骨髓间充质样干细胞治疗组肿泡炎最轻,各组比较,差异有显著件意义(p<0.05).③模型组肺组织匀浆中羟脯氨酸和肿瘤坏死囚子α含量最多,骨髓间充质样干细胞治疗最少,各组比较差异有显著性意义(P<0.05).提示骨髓间充质样干细胞和骨髓单个核细胞均可定植于损伤肺组织,并能有效阻止博莱霉素A5诱导的大鼠肺泡炎和早期纤维化,前者作用更为显著.     

核素显像评价自体骨髓单个核细胞移植治疗心肌梗死后心力衰竭

目的 核素显像观察经冠状动脉自体骨髓单个核细胞移植治疗后心肌梗死心力衰竭患者的心肌血流灌注及心功能的变化,研究自体骨髓单个核细胞移植对于心肌修复和心功能的影响.方法 24例前壁心肌梗死合并心力衰竭的患者,非随机法(患者意愿)分为两组.细胞移植组(BM-MNCs组)10例,经冠状动脉骨髓细胞注射+介入治疗+标准药物治疗;对照组14人,介入治疗+标准药物治疗.所有患者分别于移植术前、术后12个月行超声心动、心肌灌注静息显像及平衡法门控心室显像.结果 术后12个月BM-MNCs组心肌血流灌注评分明显改善(46.67±3.44 vs 29.00±4.50,P=0.0015),对照组较术前无明显改变(46.33±2.80 vs 47.00±4.12,P>0.05),两组间差异具有统计学意义(29.00±4.50 vs 47.00±4.12,P=0.0157).BM-MNCs组心肌梗死区面积明显减少[(38.00±3.86)% vs (29.44±4.73)%,P=0.0009],对照组术后无显著变化[(32.70±5.02)% vs (30.30±4.92)%],两组间的变化无统计学意义.门控心血池显像结果示:移植组术后12个月LVEF值可见轻度升高,但是差异无统计学意义,结果与超声心动图一致.结论 核素心肌显像对心肌梗死后心力衰竭患者BM-MNCs移植后的疗效判断有重要价值,自体骨髓单个核细胞移植后,心肌梗死区域血流灌注得到了明显的改善,心功能得到一定的提高.     

Energy metabolism in patients with severe heart failure

Resting energy expenditure was measured by indirect calorimetry in 11 patients (8 men, 3 women) with severe heart failure. The study was done after an over night fast (10-12 h). 5 patients suffered from idiopathic cardiomyopathy, 5 patients from coronary heart disease and 1 patient from congestive heart failure following from viral myocarditis. The cardiac index was 2.09 +/- 0.5 l/min/m2, the pulmonary capillary wedge pressure 24.6 +/- 8.0 mm Hg. Resting energy expenditure was 1.175 +/- 0.176 kcal/min/1.73 m2. The basal energy expenditure calculated according to Harris and Benedict was 1.008 +/- 0.055 kcal/min/1.73 m2. The difference was statistically significant (p less than 0.05). Respiratory quotient was 0.775 +/- 0.06 as a result of a high oxidation rate for fat (64.8% of total energy expenditure). These results show that after an overnight fast the caloric requirements of patients with severe heart failure are increased. This increased energy expenditure could be an explanation for the malnutrition often found in patients with severe chronic heart failure.     

Dilzem-retard efficiency in patients with ischemic heart disease and heart failure

Effectiveness of a prolonged form of diltiazem was studied in 20 patients with stable effort angina and chronic cardiac failure (NYHA functional class II). Dilcem-retard was given in a dose 180 mg/day for 6 months. Clinical condition, exercise tolerance, left ventricular functional and geometric parameters, heart rhythm variability, late potentials, Holter monitoring evidence were assessed before and after the treatment. Dilcem-retard improved the patients' condition, exercise tolerance, promoted normalization of left ventricular diastolic function, had no negative influence on cardiac output, reduced occurrence of sympathicotonia and late potentials.     

静脉移植骨髓间充质干细胞改善心肌病心力衰竭大鼠的心功能

目的:经静脉移植骨髓间充质干细胞至阿霉素诱导的心力衰竭大鼠体内,观察骨髓间充质干细胞对心功能的影响及其在体内的存活情况。方法:实验于2004-03/2005-11在福建省高血压研究所完成。①分离纯化近交系F344大鼠骨髓间充质干细胞进行体外培养,采用流式细胞仪检测其表面标记CD34,CD44和CD90。②10只正常大鼠作为正常对照组。32只大鼠腹腔注射阿霉素(15mg/kg)建立心肌病心力衰竭模型,然后随机分为细胞移植组16只,以5-溴-2’脱氧尿苷标记第2代骨髓间充质干细胞,经股静脉移植;移植对照组16只,移植等量DMEM培养基。③细胞移植后4周,多导生理记录仪测量3组大鼠的心功能,心脏组织切片行免疫组织化学染色,观察移植细胞在受体大鼠体内的存活情况。结果:实验中细胞移植组有4只大鼠,移植对照组有7只死亡,进入结果分析31只。①体外培养的第2代骨髓间充质干细胞均一表达CD44和CD90,不表达CD34。②心功能测定显示:细胞移植组大鼠的左室收缩压、左室内压最大上升速率和下降速率均比移植对照组明显升高[(101±7)比(76±6)mmHg,(4875±309)比(3644±380)mmHg/s,(5075±336),(3544±354)mmHg/s,P<0.05],而左室舒张末压明显降低[(15±1),(20±2)mmHg/s,P<0.05];移植对照组左室收缩压、左室内压最大上升速率和下降速率均比正常对照组明显下降(P<0.05),而左室舒张末压明显升高(P<0.05)。③免疫组织化学显示:细胞移植组大鼠的心脏组织切片上有5-溴-2’脱氧尿苷标记的移植细胞存活,并且表达心肌特异性抗原β-肌球蛋白重链;细胞移植组室间隔和左心室处血管数量均明显多于移植对照组[(9.0±1.3)比(6.5±1.9)血管数/高倍镜,(9.9±1.5)比(7.8±1.4)血管数/高倍镜,P<0.05]。结论:①经静脉移植骨髓间充质干细胞可有效改善阿霉素诱导的心力衰竭大鼠心功能。②骨髓间充质干细胞可归巢至心脏,分化为心肌样细胞。     

静脉移植骨髓间充质干细胞改善心肌病心力衰竭大鼠的心功能

目的：经静脉移植骨髓间充质干细胞至阿霉素诱导的心力衰竭大鼠体内，观察骨髓间充质干细胞对心功能的影响及其在体内的存活情况。 方法：实验于2004—03／2005—11在福建省高血压研究所完成。①分离纯化近交系F344大鼠骨髓间充质干细胞进行体外培养，采用流式细胞仪检测其表面标记CD34，CD44和CD90。②10只正常大鼠作为正常对照组。32只大鼠腹腔注射阿霉素（15mg／kg）建立心肌病心力衰竭模型，然后随机分为细胞移植组16只，以5-溴-2’脱氧尿苷标记第2代骨髓间充质干细胞，经股静脉移植；移植对照组16只，移植等量DMEM培养基。③细胞移植后4周，多导生理记录仪测量3组大鼠的心功能，心脏组织切片行免疫组织化学染色，观察移植细胞在受体大鼠体内的存活情况。 结果：实验中细胞移植组有4只大鼠，移植对照组有7只死亡，进入结果分析31只。①体外培养的第2代骨髓间充质干细胞均一表达CD44和CD90，不表达CD34。②心功能测定显示：细胞移植组大鼠的左室收缩压、左室内压最大上升速率和下降速率均比移植对照组明显升高[（101&;#177;7）比（76&;#177;6）mmHg，（4875&;#177;309）比（3644&;#177;380）mmHg／s，（5075&;#177;336），（3544&;#177;354）mmHg／s，P〈0．05]，而左室舒张末压明显降低[（15&;#177;1），（20&;#177;2）mmHg／s，P〈0．05]；移植对照组左室收缩压、左室内压最大上升速率和下降速率均比正常对照组明显下降（P〈0．05），而左室舒张末压明显升高（P〈0．05）。③免疫组织化学显示：细胞移植组大鼠的心脏组织切片上有5-溴-2’脱氧尿苷标记的移植细胞存活，并且表达心肌特异性抗原β-肌球蛋白重链；细胞移植组室间隔和左心室处血管数量均明显多于移植对照组[（9．0&;#177;1．3）比（6．5&;#177;1．9）血管数／高倍镜，（9．9&;#177;1．5）比（7．8&;#177;1．4）血管数／高倍镜，P〈0．05]。 结论①经静脉移植骨髓间充质干细胞可有效改善阿霉素诱导的心力衰竭大鼠心功能。②骨髓间充质干细胞可归巢至心脏，分化为心肌样细胞。     

自体骨髓单个核细胞移植治疗下肢缺血性疾病中细胞因子的作用

目的:评估自体骨髓单个核细胞移植治疗下肢动脉缺血性疾病中几种细胞因子的作用。方法:实验于2006-09/12在河北医科大学唐山临床学院中心实验室完成。实验材料:日本大耳白兔40只,清洁级,5月龄,体质量2.5～3.0kg,由华北煤炭医学院动物中心提供(合格证为SCXK-2005-0002),采用完全随机设计方法将日本大耳白兔分为4组:对照组、缺血组、磷酸盐缓冲液组、骨髓单个核细胞治疗组,10只/组。实验方法:对照组不作任何干预措施,其他3组建立日本大耳白兔右下肢缺血模型。取右下肢缺血模型制备2周后的兔,分离获取骨髓单个核细胞。缺血组制备右下肢缺血模型后不作其他干预措施。磷酸盐缓冲液组模型制备2周后,用1mL注射器将0.01mol/L磷酸盐缓冲液分15点注射于右下肢股骨中点股内收肌群内。骨髓单个核细胞治疗组模型制备2周后,用1mL注射器将1×109L-1骨髓单个核细胞悬液分15点注射于右下肢股内收肌群内。实验评估:造模后3d切取内收肌组织标本,测量其组织匀浆中血管内皮生长因子、碱性成纤维细胞生长因子、白细胞介素1β的含量;4周后行数字减影血管造影术,术后取右下肢内收肌标本,采用CD34免疫组织化学法检测毛细血管密度,观察下肢血管再生情况。结果:40只日本大耳白兔均进入结果分析。①移植后4周腹主动脉造影检测:骨髓单个核细胞治疗组结扎股动脉处的远端毛细血管生成较明显,血管成网状。缺血组及磷酸盐缓冲液组结扎处远端毛细血管生成不明显。②CD34免疫组织化学方法检测毛细血管密度:对照组平均为16个/×400高倍镜,缺血组和磷酸盐缓冲液组平均为5个/×400高倍镜,治疗组毛平均为20.5个/×400高倍镜。骨髓单个核细胞治疗组肌肉标本毛细血管密度明显高于缺血组和磷酸盐缓冲液组(P<0.05)。③造模后3d检测细胞因子含量:缺血组、磷酸盐缓冲液组、骨髓单个核细胞治疗组的碱性成纤维细胞生长因子含量明显高于对照组[(1.83±0.90),(3.22±2.10),(3.20±1.56),(3.75±1.07)ng/g,P<0.05]。骨髓单个核细胞治疗组白细胞介素1β含量明显高于对照组、缺血组、磷酸盐缓冲液组[(10.87±6.42),(10.74±6.32),(11.80±4.50),(16.73±4.21)ng/g,P<0.05],各组血管内皮生长因子水平差异不明显(P>0.05)。结论:自体骨髓单个核细胞移植治疗缺血性疾病过程中,白细胞介素1β对毛细血管的生成起主要作用。     

骨髓间充质干细胞动员及在缺血性心肌疾病治疗中的应用

学术背景:自体骨髓间充质干细胞动员修复坏死心肌是一种安全有效治疗缺血性心肌的方法.目的:总结骨髓间充质干细胞动员治疗缺血性心肌病的研究进展.检索策略:由作者检索Pubmed数据库1996-12/2006-12的相关文献,检索词"bone marrow stem cells,myocardial infarction".对资料进行初审,纳入标准:①与骨髓间充质干细胞治疗缺血性心肌疾病中的应用.②同一领域选择近期发表或在权威杂志上发表的文章.排除标准:重复性研究.文献评价:文献的来源主要是骨髓间充质干细胞治疗缺血性疾病的随机对照试验.所选用的28篇文献中,2篇为综述,其余均为临床或基础实验研究.资料综合:①骨髓间充质干细胞具有自我更新、增殖和多向分化潜能,在合适细胞因子调控下可分化为心肌样细胞.②研究表明,骨髓血液循环中的干细胞可以定向到达梗死心肌并参与组织再生.③关于骨髓间充质干细胞在治疗缺血性心脏疾病方面的研究虽已取得较大进展,但仍存在许多问题,如种子细胞的保存:细胞体外培养中分化增殖的调控机制不十分清楚:产生的心肌样细胞的生物力学性能不太满意.结论:骨髓间充质干细胞动员在治疗缺血性心肌病方面,具有操作方法简便、快捷,对患者创伤小,自体移植不存在免疫排斥的优势,但仍存在许多尚未解决的问题.     

经冠状动脉移植自体骨髓单个核细胞用于治疗心肌梗死后的心力衰竭

目的:观察经冠状动脉直接注射进行自体骨髓单个核细胞移植时细胞能否进入心肌组织并有效改善心肌梗死后的心脏功能。方法:成年犬24只,随机分为对照组与移植组,移植组于移植前一天抽取骨髓液分离骨髓单个核细胞(数量约为2×108)。结扎冠状动脉左前降支后,移植组于冠状动脉内注射骨髓单个核细胞悬液,对照组注射培养基。6周后处死动物,比较其心肌梗死面积、瘢痕区毛细血管数量、超声心动图指标及血流动力学指标的变化。结果:对照组和移植组各死亡4只犬,分别有8只犬进入结果分析。①各组犬心脏标本病理研究结果:骨髓单个核细胞经5-溴脱氧尿嘧啶核苷标记的阳性率约为50%;移植6周后于梗死区的心肌组织内能够检测到5-溴脱氧尿嘧啶核苷标记阳性的细胞;移植组的梗死区面积和梗死范围比对照组分别下降了30.9%和35.0%,但无显著性差别(P均>0.05);瘢痕区每个高倍视野(0.2mm2)的毛细血管数量,移植组为5.33±0.58,明显高于对照组2.03±0.46(P<0.01)。②血流动力学指标的变化:移植组与对照组相比,6周时左室内压最大上升速率、最大下降速率及心输出量均显著上升[(3039±1164)比(1569±618)mmHg/s,P<0.01;(2951±793)比(1465±647)mmHg/s,P<0.01;(1.88±0.33)比(1.41±0.29)L/min,P<0.05]。③超声心动图心功能指标的变化:移植组左室射血分数明显高于对照组(46.01%,35.28%,P<0.05)。④不良事件和副反应:在实验中仅在移植组1例实验犬的细胞注射部位观察发现一炎性包块,移植后6周时观察未见明确的恶性心律失常出现及肿瘤组织形成。结论:经冠状动脉直接注射进行骨髓单个核细胞移植可行且安全,它能够促进梗死区的新血管生成并有效改善心肌梗死后的心脏功能。     

Intermittent levosimendan treatment in patients with severe congestive heart failure

Objective

Levosimendan (LS) is a novel inodilator for the treatment of severe congestive heart failure (CHF). In this study, we investigated the potential long-term effects of intermittent LS treatment on the pathophysiology of heart failure.

Methods

Thirteen patients with modest to severe CHF received three 24-h intravenous infusions of LS at 3-week intervals. Exercise capacity was determined by bicycle ergospirometry, well-being assessed by Minnesota Living with Heart Failure Questionnaire (MLHFQ) and laboratory parameters of interest measured before and after each treatment.

Results

One patient experienced non-sustained periods of ventricular tachycardia (VT) during the first infusion and had to discontinue the study. Otherwise the LS infusions were well tolerated. Exercise capacity (VO_2max) did not improve significantly during the study although symptoms decreased (P < 0.0001). Levels of plasma NT-proANP, NT-proBNP and NT-proXNP decreased 30–50 % during each infusion (P < 0.001 for all), but the changes disappeared within 3 weeks. Although norepinephrine (NE) appeared to increase during the first treatment (P = 0.019), no long-term changes were observed.

Conclusion

Intermittent LS treatments decreased effectively and repetitively plasma vasoactive peptide levels, but no carryover effects were observed. Patients’ symptoms decreased for the whole study period although there was no objective improvement of their exercise capacity. The prognostic significance of these effects needs to be further studied.     

高龄重度心功能不全患者的护理评估

INTRODUCTION Severe heart failure threatens people's health,especially old patients.Nursing assessment for patients with congestive heart failure is an important premise for improvement of nursing quality.     

Captopril inhibits the production of tumor necrosis factor-alpha by human mononuclear cells in patients with congestive heart failure

To study the effects of captopril on tumor necrosis factor-alpha produced by peripheral blood mononuclear cells (PBMC) of patients with congestive heart failure (CHF), we determined the TNF-alpha concentrations of culture supernatants of PBMC with and without catopril in 74 CHF patients with various heart diseases. The results showed that the supernatants concentrations of TNF-alpha in cultured PBMC (PBMC-TNF-alpha) were significantly increased in non-cachetic and cachetic CHF patients, and even higher in cachetic CHF patients, as compared with the controls (i.e., patients with New York Heart Association CHF classification I). The PBMC-TNF-alpha was significantly inhibited by captopril. These results demonstrate that the expression of TNF-alpha in PBMC is increased and can be inhibited by captopril in patients with CHF, especially in those accompanied by cachexia. This suggests that the immunomodulatory effects of captopril may contribute to its beneficial effects in heart failure patients.     

Contribution of bone marrow-derived cells to blood vessels in ischemic tissues and tumors.

Vessels are formed during embryonic development through three distinct processes. Angiogenesis and arteriogenesis involve the remodeling of established capillary networks and arterioles, while vasculogenesis involves the differentiation of mesodermal progenitor cells called angioblasts into mature endothelial cells. Until recently, postnatal vessel development was felt to occur exclusively through angiogenesis or arteriogenesis. However, recent studies using experimental tumor and ischemia models have raised controversy regarding whether vasculogenesis occurs in postnatal vessel development, with some studies suggesting the possibility and others refuting it. Here, we summarize the process of embryonic vessel development and review studies investigating the role of postnatal vasculogenesis in vessel formation in adult ischemia and tumors. We then focus on studies in which wild-type and genetically modified vascular progenitor cells have been investigated as possible cellular therapies for tumors or ischemia. We also take note of key issues that will need to be understood about the biology of vasculogenesis before cellular therapies utilizing vascular progenitor cells can be finally taken from the bench to the bedside.