A fibrin patch-based enhanced delivery of human embryonic stem cell-derived vascular cell transplantation in a porcine model of postinfarction left ventricular remodeling

It is unknown how to use human embryonic stem cell (hESC) to effectively treat hearts with postinfarction left ventricular (LV) remodeling. Using a porcine model of postinfarction LV remodeling, this study examined the functional improvement of enhanced delivery of combined transplantation of hESC-derived endothelial cells (ECs) and hESC-derived smooth muscle cells (SMCs) with a fibrin three-dimensional (3D) porous scaffold biomatrix. To facilitate tracking the transplanted cells, the hESCs were genetically modified to stably express green fluorescent protein and luciferase (GFP/Luc). Myocardial infarction (MI) was created by ligating the first diagonal coronary artery for 60 minutes followed by reperfusion. Two million each of GFP/Luc hESC-derived ECs and SMCs were seeded in the 3D porous biomatrix patch and applied to the region of ischemia/reperfusion for cell group (MI+P+C, n = 6), whereas biomatrix without cell (MI+P, n = 5), or saline only (MI, n = 5) were applied to control group hearts with same coronary artery ligation. Functional outcome (1 and 4 weeks follow-up) of stem cell transplantation was assessed by cardiac magnetic resonance imaging. The transplantation of hESC-derived vascular cells resulted in significant LV functional improvement. Significant engraftment of hESC-derived cells was confirmed by both in vivo and ex vivo bioluminescent imaging. The mechanism underlying the functional beneficial effects of cardiac progenitor transplantation is attributed to the increased neovascularization. These findings demonstrate a promising therapeutic potential of using these hESC-derived vascular cell types and the mode of patch delivery.     

血管内皮生长因子基因转染骨髓间充质干细胞同种异体移植治疗大鼠急性心肌梗死

目的探讨同种异体血管内皮生长因子(VEGF)基因转染的骨髓间充质干细胞(MSCs)在大鼠梗死心脏局部存活、分化及对心功能的影响;明确同种异体干细胞及VEGF基因转染干细胞移植治疗急性心肌梗死(AMI)的可行性及效果。方法雄性SD大鼠30只,随机分为单纯注射培养基对照组、MSCs治疗组及VEGF基因转染MSCs治疗组。分离纯化雄性Wistar大鼠骨髓间充质干细胞(rMSCs),于左冠状动脉前降支结扎1h后植入到SD大鼠心组织,移植4周后检测心功能并取心脏行组织染色检查。结果异体大鼠MSCs可在梗死心组织定居、生存;免疫组化检测MSCs转化为心肌细胞及血管内皮细胞;与对照组比较VEGF基因转染异体细胞移植组左室射血分数升高(P<0.05),梗死边缘区心肌面毛细血管数目明显增加(P<0.05)。结论同种异体VEGF基因转染MSCs移植治疗AMI可行、有效。     

Minimal engraftment of human CD34+ cells mobilized from healthy donors in the infarcted heart of athymic nude rats

Cell-based regenerative therapy may be useful for treatment of acute myocardial infarction (AMI). Animal xenograft models are ideally suited for preclinical studies evaluating prospective treatment regimes, identifying candidate human cell populations, and gaining mechanistic insight. Here we address whether the athymic nude rat is suitable as a xenograft model for the study of human CD34+ mobilized peripheral blood stem cells (M-PBSCs) in the repair of AMI. We injected human donor cells into the infarct border of athymic nude rats with surgically induced AMI and evaluated engraftment and functional improvement. We found no human engraftment by immunofluorescence staining at 14 days after transplantation or functional improvement at days 2 and 14 compared to controls. The lack of long-term human engraftment was furthermore confirmed in a time series study analyzing animals at 0, 24, 48, 72, and 96 h after transplantation. Although we found fluorescent microbeads coinjected with human CD34+ M-PBSCs at all time points, the number of donor cells rapidly declined and became undetectable at 96 h. CD34+ M-PBSCs from the same donor used to treat athymic nude rat hearts engrafted the bone marrow of nonobese diabetic/severe combined immunodeficient mice 8-10 weeks after transplantation. In conclusion, human CD34+ M-PBSCs with confirmed hematopoietic engraftment potential rapidly disappeared from the site of injury following intramyocardial transplantation in the athymic nude rat AMI model.     

阿托伐他汀对糖尿病大鼠急性心肌梗死后心功能及HGF/c-Met信号通路的影响*

 目的： 糖尿病患者急性心肌梗死（AMI）后的心室重构及心功能恶化较非糖尿病者更为明显。本研究旨在观察阿托伐他汀对糖尿病大鼠AMI后心肌细胞凋亡、心室重构及心功能的影响,并探讨其作用是否与肝细胞生长因子及其受体 (HGF/c-Met)信号通路有关。方法: 70只雄性SD大鼠经链脲霉素 (STZ, 65 mg/kg)腹腔注射,诱导糖尿病大鼠模型。8周后对糖尿病大鼠结扎左冠状动脉前降支构建AMI大鼠模型,术后存活32只大鼠随机分为2组：AMI对照组(n=16)和阿托伐他汀干预组(n=16, 阿托伐他汀20 mg·kg-1·d-1),并在糖尿病大鼠中设假手术组(n=11),术后24 h予以灌胃给药。2周后比较各组大鼠心功能、心肌组织病理改变、心肌细胞凋亡、HGF和c-Met mRNA及蛋白表达差异。结果: (1) AMI对照组心功能显著低于假手术组（P<0.05）,胶原容积分数、心肌细胞凋亡指数、HGF及c-Met mRNA及蛋白表达均显著高于假手术组（P<0.05）;(2) 阿托伐他汀干预组的胶原容积分数和心肌细胞凋亡指数显著低于AMI对照组（P<0.05）,心功能、HGF及c-Met mRNA及蛋白表达均显著高于AMI对照组（P<0.05）。结论: 阿托伐他汀对糖尿病大鼠AMI后心肌细胞凋亡、心室重构及心功能具有显著改善作用;HGF/c-Met信号通路在AMI后会激活,阿托伐他汀的上述作用机制可能与其进一步增强HGF/c-Met信号通路有关。     

Posttransplant thrombopoiesis predicts survival in patients undergoing autologous hematopoietic progenitor cell transplantation.

The frequency and clinical significance of secondary thrombocytopenia following initial engraftment in autologous hematopoietic progenitor cell transplantation (HPCT) is unknown. An institutional review board approved retrospective study of thrombopoiesis was performed in 359 patients transplanted with autologous blood (97%) or marrow (3%) who achieved platelet engraftment to >50,000/microL. Idiopathic secondary posttransplant thrombocytopenia (ISPT) was defined as >50% decline in blood platelets to <100,000/microL in the absence of relapse or sepsis. ISPT occurred at a median of day +35 posttransplant in 17% of patients. Patients with ISPT had similar initial platelet engraftment (median 17 days) versus non-ISPT patients (18 days; P=NS) and recovered platelet counts (median 123,00 K/microL) by day 110 posttransplant. Four factors were independently associated with post-transplant death in a multivariate model: disease status at transplant; the number of prior chemotherapy regimens, failure to achieve a platelet count of >150,000/microL posttransplant, and the occurrence of ISPT. A prognostic score was developed based upon the occurrence of ISPT and posttransplant platelet counts of <150,000/microL. Survival of patients with both factors (n=25) was poor (15% alive at 5 years); patients with 1 factor (n=145) had 49% 5-year survival; patients with 0 factors (n=189) had 72% 5-year survival. Patients who failed to achieve a platelet count of >150,000/microL received significantly fewer CD34+ cells/kg (P<.001), whereas patients with ISPT received fewer CD34+CD38- cells/kg (P=.0006). The kinetics of posttransplant thrombopoiesis is an independent prognostic factor for long-term survival following autologous HPC. ISPT and lower initial posttransplant platelet counts reflect poor engraftment with long-term and short-term repopulating CD34+ hematopoietic stem cells, respectively, and are associated with an increased risk of death from disease relapse.     

卡维地洛、西拉普利及其合用防治大鼠急性心肌梗死左室重塑的作用

目的:评价卡维地洛、西拉普利及其合用防治大鼠急性心肌梗死(AMI)左室重塑(LVRM)的作用。方法:AMI术后24h存活的100只雌性SD大鼠随机分成:①AMI对照(n=25)、②AMI+卡维地洛(1mg·kg^-1·d^-1, n=25)、③AMI+西拉普利(1mg·kg^-1·d^-1, n=25)及④AMI+合用(n=25)4组;另设假手术组(n=17).直接灌胃给药。4周后行血流动力学测定和病理学分析。去除梗死面积<35%或>55%者, 最终在以上各组分别有(13, 12, 12, 14)和13只大鼠。结果:AMI各组间梗死面积差异均无显著性(45.2%-46.7%, 均P>0.05).AMI对照组的左室舒张末压(LVEDP)、容积(LVV)、重量(LVW)和室间隔厚度(STh)均显著大于假手术组(均P<0.01), 左室内压最大上升和下降速率(±dp/dt)及其校正值(±dp/dt/LVSP)均显著低于假手术组(P<0.05, P<0.01).卡维地洛、西拉普利及合用组的LVEDP、LVV均显著低于AMI对照组(P<0.01), STh均显著薄于AMI对照组(P<0.01), LVW均显著轻于AMI对照组(P<0.05, P<0.01), ±dp/dt显著高于AMI对照组(P<0.05, P<0.01), 且LVEDP和STh在合用组显著低于两单用药组(P<0.05, P<0.01), 余指标在3个用药组间差异均无显著性(均P>0.05).结论:卡维地洛、西拉普利及其合用均能有效防治大鼠AMI左室重塑并改善血流动力学和左室功能,且以合用更佳。     

Controlled release of stromal cell-derived factor-1 alpha in situ increases c-kit+ cell homing to the infarcted heart

Stromal-derived factor 1alpha (SDF-1alpha) is a key stem cell homing factor that is crucial for mobilization of stem cells from bone marrow to peripheral blood and subsequent engraftment to the tissue of diseased organs. It has been reported that SDF-1alpha is transiently over-expressed in ischemic myocardium. Therefore, there may be a limited time window after acute myocardial infarction (AMI) during which stem cells are recruited to injured myocardium for repair. This study aimed at investigating whether controlled release of SDF-1alpha via a novel conjugated poly(ethylene glycol) (PEG) (PEGylated) fibrin patch at the infarct site would increase the rate of stem cell recruitment and offer potential therapeutic benefits. Recombinant mouse SDF-1alpha was covalently bound to the PEGylated fibrinogen as evidenced by immunoprecipitation and western blotting. The PEGylated fibrinogen, bound with recombinant mouse SDF-1alpha, was mixed with thrombin to form the PEGylated fibrin patch. The release kinetics of SDF-1alpha were detected in vitro using enzyme-linked immunosorbent assay. Using a mouse AMI model produced by a ligature on the left anterior descending coronary artery, a PEGylated fibrin patch bound with SDF-1alpha (100 ng) was placed on the surface of the infarct area of the left ventricle. Infarct size, left ventricular (LV) function, and the percentage of sca-1(+)/c-kit(+) cells within the infarct area were measured at days 7, 14, and 28 after AMI. In vitro results showed that SDF-1alpha was successfully bound to the PEGylated fibrin patch and can be released from the patch constantly for up to 10 days. Two weeks after infarction, the myocardial recruitment of c-kit(+) cells was significantly higher in the group treated with the SDF-1alpha PEGylated fibrin patch (n = 9) than in the AMI control group (n = 10) (p < 0.05; 11.20 +/- 1.71% vs. 4.22 +/- 0.96%, respectively). At day 28 post-AMI, unlike the control group, the group with the SDF-1alpha-releasing patch maintained stable release of SDF-1alpha concurrent with additional stem cell homing. Moreover, LV function was significantly better than in the control group. These data demonstrate that the PEGylated fibrin patch based SDF-1alpha delivery can improve the rate of c-kit(+) cell homing and improve LV function in hearts with postinfarction LV remodeling.     

同种异体脂肪组织源性间质干细胞移植治疗大鼠急性心肌梗死

目的：建立体外分离扩增脂肪组织源性间质干细胞方法，并探讨同种异体脂肪干细胞移植治疗大鼠心肌梗死的效果及可行性。方法: 18只雄性SD大鼠随机分为假手术组、急性心肌梗死对照组（AMI组）及AMI+细胞移植组。分离大鼠腹部脂肪组织干细胞，体外扩增，BrdU标记后于结扎左冠状动脉前降支后1h移植入梗死心肌，移植后4周进行血流动力学检测心功能并取出心脏进行病理切片观察和免疫组织化学染色检测移植细胞在梗死心脏中的定居、存活情况。结果: 大鼠腹部脂肪组织可分离培养出大量间质干细胞。细胞移植治疗组左心室收缩压高于AMI对照组（P＜0.01），舒张末压显著降低（P＜0.01），左心室内压最大上升、下降速率明显加快（P＜0.05）；病理组织切片显示梗死边缘区心肌面毛细血管计数明显增加，梗死区心肌组织内及毛细血管壁中均可见移植标记细胞。结论: 脂肪组织可作为干细胞又一新的来源，同种异体脂肪干细胞移植治疗AMI有效、可行。     

Effect of a flexible ventricular restraint device on cardiac remodeling after acute myocardial infarction

The effects of a flexible ventricular restraint device on left ventricular (LV) dilatation and hypertrophy after transmural infarction are examined in an ovine model. Left ventricular remodeling and dilatation occurs after extensive myocardial infarction. A flexible ventricular restraint made from a nitinol mesh was evaluated in adult female sheep (n=14). Cardiac magnetic resonance imaging scans and hemodynamic measurements were completed before and 6 weeks after anterior myocardial infarction. Treatment animals (n=7) received passive ventricular restraint concurrently with LV infarction; the others (n=7) served as controls. Increases in LV end-diastolic volume index were significantly less in the restraint group than in controls (0.20+/-0.41 vs 0.83+/-0.50 ml/kg, p<0.03). End-systolic volumes increased less in treatment animals (0.43+/-0.28 vs 0.90+/-0.38 ml/kg, p<0.03). Control hearts showed an increase in LV mass after infraction, whereas LV mass decreased in restrained hearts (0.14+/-0.19 vs -0.25+/-0.36 g/kg, p<0.03). Hemodynamic studies showed similar changes after infarction for the control and the device group. Gross and microscopic examination showed no device-induced epicardial injury. A flexible ventricular restraint device attenuated remodeling after acute myocardial infarction in sheep.     

Detrimental effects after dobutamine infusion on rat left ventricular function: mechanical work and energetics

We have previously reported that continuous infusion of dobutamine into the coronary artery induces positive inotropic effects but induces no detrimental effects in cross-circulated, excised normal rat hearts and even in Ca2+ overload-induced contractile failing rat hearts. However, we hypothesized that some detrimental effects on left ventricular (LV) function are induced after continuous dobutamine infusion and the following clearance of blood dobutamine, as is the case after beta-adrenergic receptor stimulation. To test this hypothesis, we investigated LV mechanical work and energetics in the same type of preparations that underwent continuous dobutamine infusion and clearance of blood dobutamine. We found that both mean end-systolic pressure and systolic pressure-volume area (PVA; a measure of total mechanical energy per beat) at midrange LV volume were significantly (P < 0.01) decreased. The mean myocardial oxygen consumption per beat intercept, which is composed of for the total Ca2+ handling in excitation-contraction coupling and basal metabolism, of the and PVA linear relation was also significantly (P < 0.05) decreased (n=8). The mean slope of the linear relation was unchanged in such hearts. Post-dobutamine basal metabolism was unchanged (n = 5 of the 8 hearts). The moderate proteolysis of a cytoskeleton protein, alpha-fodrin was identified (n = 7 of the 8 hearts with the decreased intercept), after clearance of blood dobutamine. In agreement with our hypothesis, the detrimental effect of the post-beta-adrenergic receptor stimulation was induced by a moderate concentration of dobutamine; we found systolic dysfunction due to the impairment of Ca2+ handling in excitation-contraction coupling in the rat LV and proteolysis of a cytoskeleton protein, alpha-fodrin.     

Swimming exercise training prior to acute myocardial infarction attenuates left ventricular remodeling and improves left ventricular function in rats

The effect of exercise training prior to acute myocardial infarction (AMI) on left ventricular (LV) remodeling is poorly understood. This study investigated the protective effect of 3 weeks of swimming exercise training prior to AMI on cardiac morphology and function. Male Sprague-Dawley rats (n = 35) were randomly assigned to 3 groups: swimming training (n = 14, 90 min, 5 days/wk, 3 wk), sedentary (n =14), and controls (n = 7, no exercise, no MI). At the end of the training/sedentary period, rats were subjected to AMI (ExMI and SedMI) induced by surgical ligation of the left coronary artery. Thereafter, the rats remained sedentary for a 4-wk recovery period. Trans-thoracic echocardiography was performed in each group at the end of the exercise/sedentary period (pre-AMI), 24 hr after AMI, and following recovery (4 wk after AMI). No differences were observed in LV dimensions and function pre-AMI among the 3 groups; however, LV-end systolic diameter (LVESD) and LV-end systolic area (LVES-area) were significantly lower in the prior trained rats, 24 hr post-AMI with no additional change 4 wk post-AMI, during remodeling. Both LV-shortening fraction (SF%) and fractional area change (FAC%) were higher in the trained animals 4 wk post-AMI (39+/-12% vs 23+/-8%; p 0.002, and 48+/-14% vs. 38+/-9%; p 0.07, respectively). In conclusion, 3 wk of swimming exercise training prior to AMI significantly attenuated LV remodeling and improved LV function, despite no changes in LV dimensions or systolic function at the end of the exercise session. The data suggest that even a short-term training period is sufficient to induce cardiac protection.     

Umbilical cord blood transplantation in adults: results of the prospective Cord Blood Transplantation (COBLT).

The Cord Blood Transplantation study group conducted a prospective study of unrelated cord blood transplantation (CBT) to better define the role of this stem cell source for subjects requiring unrelated allogeneic transplantation. We report on 1 stratum of the study designated for adult subjects. The primary end point of the study was survival at 180 days. Secondary end points included engraftment, graft-versus-host disease, relapse, and long-term survival. Eligibility criteria for malignant and nonmalignant diseases were specified. Subjects with active central nervous system disease, Karnofsky performance status <70%, grade 3 or 4 or primary myelofibrosis, or suitable related donors were excluded. Enrollment required a single cord blood unit containing >10(7) nucleated cells per kilogram of recipient weight and matched at > or =4 HLA-A and -B (low or intermediate resolution) and -DRB1 (high resolution) types. Thirty-four subjects were entered, with a median age of 34.5 years (range, 18.2-55 years). Most subjects (n = 23) had a 4 of 6 match, 10 subjects had a 5 of 6 match, and 1 subject had a 6 of 6 match. Diagnoses at transplantation included acute myelogenous leukemia (n = 19), acute lymphoblastic leukemia (n = 9), chronic myelogenous leukemia (n = 3), myelodysplastic syndrome (n = 1), paroxysmal nocturnal hemoglobinuria (PNH) (n = 1), and non-Hodgkin lymphoma (n = 1); 94% were classified as poor risk according to National Marrow Donor Program criteria. Subjects received total body irradiation/cyclophosphamide (n = 27) or busulfan/melphalan (n = 7) conditioning regimens. Four subjects died before CBT and are described here but are not included in the main analysis. The cumulative incidence rates and median times to neutrophil (500/microL) and platelet (>20,000/microL) engraftment were 0.66 by day 42 (median, 31 days) and 0.35 by day 180 (median, 117 days). The cumulative incidence rate for grade II-IV GVHD was 0.34 by day 100. For the primary end point, survival at 180 days, Kaplan-Meier survival estimates were 0.30 (95% confidence interval, 0.14-0.46) by day 180 after transplantation. To date there are 2 survivors, and both are >36 months from enrollment. A retrospective analysis was performed by using high-resolution HLA-A and -B typing, which revealed that approximately one third of subjects had 1 or more additional HLA mismatches compared with results of low- or intermediate-resolution HLA typing. The findings of high treatment-related mortality and slow engraftment kinetics indicate that CBT should continue to be performed in specialized centers with a research focus on cord blood cells.     

Transplantation of bone marrow-derived very small embryonic-like stem cells attenuates left ventricular dysfunction and remodeling after myocardial infarction

Adult bone marrow (BM) contains Sca-1+/Lin-/CD45- very small embryonic-like stem cells (VSELs) that express markers of several lineages, including cardiac markers, and differentiate into cardiomyocytes in vitro. We examined whether BM-derived VSELs promote myocardial repair after a reperfused myocardial infarction (MI). Mice underwent a 30-minute coronary occlusion followed by reperfusion and received intramyocardial injection of vehicle (n= 11), 1 x 10(5) Sca-1+/Lin-/CD45+ enhanced green fluorescent protein (EGFP)-labeled hematopoietic stem cells (n= 13 [cell control group]), or 1 x 10(4) Sca-1+/Lin-/CD45- EGFP-labeled cells (n= 14 [VSEL-treated group]) at 48 hours after MI. At 35 days after MI, VSEL-treated mice exhibited improved global and regional left ventricular (LV) systolic function (echocardiography) and attenuated myocyte hypertrophy in surviving tissue (histology and echocardiography) compared with vehicle-treated controls. In contrast, transplantation of Sca-1+/Lin-/CD45+ cells failed to confer any functional or structural benefits. Scattered EGFP+ myocytes and capillaries were present in the infarct region in VSEL-treated mice, but their numbers were very small. These results indicate that transplantation of a relatively small number of CD45- VSELs is sufficient to improve LV function and alleviate myocyte hypertrophy after MI, supporting the potential therapeutic utility of these cells for cardiac repair. Disclosure of potential conflicts of interest is found at the end of this article.     

High CD34+ cell dose promotes faster platelet recovery after autologous stem cell transplantation for acute myeloid leukemia.

We studied platelet engraftment in 58 patients with acute myeloid leukemia in first remission treated with autologous stem cell transplantation (ASCT) to determine whether CD34+ cell doses >10 x 10(6)/kg were associated with faster platelet engraftment. We compared engraftment rates in patients receiving CD34+ doses between 5 and 10 x 10(6)/kg (standard-dose ASCT) with those receiving doses > or =10 x 10(6)/kg (high-dose [HD] ASCT). We also studied neutrophil engraftment rates and platelet and red blood cell transfusion requirements. In multivariate adjusted models, the rate of platelet recovery to > or =20,000/microL was 4-fold greater among subjects who received HD-ASCT (hazard ratio [HR], 4.1; confidence interval [CI], 1.8-9.2; P =.001), with median recovery times of 14 versus 28 days. The rate of platelet recovery to > or =50,000/microL was 2-fold greater (HR, 2.1; CI, 1.3-5.9; P =.01), with median recovery times of 19 versus 46 days. Faster platelet recovery resulted in the need for fewer platelet transfusions among the subjects who received HD-ASCT (mean transfusions, 3.7 versus 9.8; P =.005). Although not statistically significant, neutrophil recovery data in the adjusted model suggested a similar effect in the HD-ASCT group, with faster engraftment times at absolute neutrophil counts >500/microL (median, 9.2 versus 12 days; HR, 1.6; CI, 0.69-3.5; P =.29) and absolute neutrophil counts >1000/microL (median, 9.5 versus 12 days; HR, 1.3; CI, 0.56-2.8; P =.58). Subjects who received HD-ASCT required fewer red blood cell transfusions (4.0 versus 9.8 units; P =.01). Our findings suggest that CD34+ cell doses >10 x 10(6)/kg CD34+ result in faster engraftment and fewer red blood cell and platelet transfusions.     

Recovery of cardiac function after standard hypothermic storage versus preservation with Peg-hemoglobin

Preservation of the heart for transplantation after infusion of cardioplegia and extirpation of a cardiac allograft results in an ischemic insult to the myocardium. This ischemic insult may lead to a loss of function in the transplanted heart. Hypothermic perfusion preservation with an oxygen hemoglobin carrying solution may avert ischemic injury and lead to improved recovery of cardiac function. The purpose of this study was to compare cardiac function after 8 hours of continuous hypothermic perfusion with a unique polyethylene-glycol-hemoglobin (PEG-Hb) solution to hearts preserved by 4 hours of hypothermic ischemic storage. Freshly extirpated hearts served as functional controls. The hearts of 26 anesthetized and intubated New Zealand white rabbits were harvested after cold cardioplegic arrest. Group I (n = 12) hearts were perfused with a PEG-Hb solution at 20 degrees C and 30 mm Hg for 8 hours. PO2 was maintained > or = 500 mm Hg. Group II (n = 7) hearts were preserved by cold ischemic storage for 4 hours at 4 degrees C. Group III (n = 7) were tested immediately after harvest. Left ventricular (LV) function was measured in the nonworking state at 15 minutes, 1 hour, and 2 hours after transfer to a standard crystalloid Langendorff circuit. Measurement of LV developed pressure, peak + dP/dt and -dP/dt revealed a superior trend between Group I and Group II hearts in comparison with freshly extirpated hearts. Heart rate was similar among all groups throughout testing (p = ns). Coronary blood flow was not significantly different between groups. Continuous perfusion preservation of rabbit hearts for 8 hours with PEG-Hb solution at 30 mm Hg and 20 degrees C yielded LV function that was similar to 4 hours of ischemic hypothermic storage. Furthermore, return of cardiac function after 8 hours of perfusion preservation using this PEG-Hb solution may be superior to that obtained in freshly extirpated hearts. These data suggest that some recovery of myocardial function may occur during perfusion preservation with this PEG-Hb solution after the ischemic insult of cardioplegic arrest. Continuous perfusion preservation using this PEG-Hb solution deserves further investigation in large animal transplant models.     

Hematopoietic Stem Cell Transplantation in Solid Organ Recipients with Emphasis on Transplant Complications: A Nationwide Retrospective Survey on Behalf of the Japan Society for Hematopoietic Stem Cell Transplantation Transplant Complications Working Group

Little is known about stem cell transplantation in solid organ transplantation (SOT) recipients. We conducted a nationwide retrospective survey of Japan Society for Hematopoietic Stem Cell Transplantation centers. A total of 19 patients who underwent 22 hematopoietic stem cell transplantations (HSCTs) after SOT were identified: 5 autologous HSCTs and 17 allogeneic HSCTs were performed. Patients who underwent autologous HSCT received a liver (n = 4) or kidney (n = 1) transplant. All 5 patients achieved neutrophil engraftment, and 2 of 3 patients with hepatoblastoma were alive at 1 year after HSCT. Allogeneic HSCT was performed in 16 patients (7 liver transplant recipients and 9 kidney transplant recipients). Among these, 2 donors were identical for both transplantations. All but 1 patient achieved neutrophil engraftment. The 5-year overall survival rate was 41.7%, but that in patients with malignant disease (n = 13) was much lower than the overall rate (23.1%). Only 1 patient with malignant disease underwent allogeneic HSCT in nonremission. In allogeneic HSCT after kidney transplantation, post-transplantation (1 year) kidney function in 5 evaluable patients was significantly lower than that before allogeneic HSCT, and 3 patients experienced renal rejection. However, no severe hepatic rejection was noted. In SOT recipients, HSCT is a potentially curable treatment for hematologic disorders, but it must be performed with caution, especially in patients with malignancy.     

Human umbilical cord blood-derived CD133+ cells enhance function and repair of the infarcted myocardium

The use of adult stem cells for myocardial tissue repair might be limited in elderly and sick people because their cells are depleted and exhausted. The present study was conducted to explore the potential of human umbilical cord blood (UCB) CD133+ progenitor cells for myocardial tissue repair in a model of extensive myocardial infarction (MI). CD133+ progenitor cells were isolated from newborn UCB. Cells (1.2-2 x 10(6)) or saline (control) was infused intravenously 7 days after permanent coronary artery ligation in athymic nude rats. Left ventricular (LV) function was assessed before and 1 month after infusion by echocardiography. Tracking of human cells was performed by fluorescent in situ hybridization for human X and Y chromosomes or by immunostaining for HLA-DR or HLA-ABC. One month after delivery, LV fractional shortening improved by 42 +/- 17% in cell-treated hearts and decreased by 39 +/- 10% in controls (p = .001). Anterior wall thickness decreased significantly in controls but not in treated hearts. Microscopic examination revealed that the UCB cells were able to migrate, colonize, and survive in the infarcted myocardium. Human cells were identified near vessel walls and LV cavity and were occasionally incorporated into endothelial cells in six of nine cell-treated animals but not in controls. Scar tissue from cell-treated animals was significantly populated with autologous myofibroblasts as indicated by colocalization of HLA-DR and alpha-smooth muscle actin staining. In conclusion, the present work suggests that, after MI, intravenous delivery of human UCB-derived CD133+ cells can produce functional recovery by preventing scar thinning and LV systolic dilatation.     

Role of the CD34+ 38- cells in posttransplant hematopoietic recovery

Using three different statistical tests in parallel, we showed in a preliminary study that neither mononuclear cells, CD34+ 33+ or 33- cells, nor CD34+ 38+ cells significantly correlated with engraftment kinetics following autologous blood cell transplantation (ABCT). We additionally demonstrated here, in a series of patients suffering from malignant diseases, that the graft content in CD34+ 38- cells is individually a more sensitive indicator of the earliest, as well as the latest post-ABCT trilineage hematopoietic recovery than the colony-forming units-granulocyte-macrophage and even the total CD34+ cell content. This suggests that the CD34+ 38- cell population is itself subdivided into two more subsets, one being already lineage-committed and responsible for short-term engraftment, the other containing only very primitive hematopoietic cells responsible for sustained engraftment. Strong arguments favor the probability that these subsets correspond to HLA-DR+ and DR cells, respectively. We also defined an optimal threshold value of 0.05 x 10(6) CD34+ 38- cells/kg of the patient's body weight (b.w.) above which a rapid and sustained trilineage engraftment safely occurs. In fact, infusion of lower numbers of cells seems to have a more significant impact on long-term compared to short-term neutrophil recovery and on platelet kinetics engraftment. We additionally looked for the eventual influence on engraftment time of the type of disease, and of post-ABCT administration of hematopoietic growth factors (HGF). When the type of disease appeared to have no influence on the engraftment time, posttransplant HGF administration significantly reduced the time to trilineage engraftment in patients transplanted with < 0.05 x 10(6) CD34+ 38- cells, thus justifying it in case of reinfusion of low numbers of CD34+ 38- cells. On the other hand, the administration of HGF after infusion of more than 0.05 x 10(6) CD34+ 38- cells/kg b.w. did not hasten more, or only very little, the engraftment time, thus becoming not only unprofitable for the patients but costly as well.     

Extended ex vivo myocardial preservation in the beating state using a novel polyethylene glycolated bovine hemoglobin perfusate based solution

Cardiac preservation for transplantation is generally limited by ischemic hypothermic storage of 4-6 hours. Earlier studies in the authors' laboratory have demonstrated that hypothermic perfusion preservation using a novel oxygen carrying hemoglobin solution may extend preservation times to 8 hours and decrease ischemic injury. The purpose of this study was to compare extended cardiac function after 12 and 24 hours of continuous hypothermic perfusion with a polyethylene glycolated bovine hemoglobin perfusate (PEG-Hb) solution to the clinical standard of hypothermic ischemic preservation. The hearts of 54 anesthetized and intubated New Zealand White rabbits were harvested after cold cardioplegic arrest. Group I (n = 12) hearts were perfused with a PEG-Hb solution at 20 degrees C and 30 mm Hg for 24 hours. Group II (n = 10) hearts were preserved similarly with PEG-Hb for 12 hours. Group III (n = 12) hearts were preserved for 8 hours with PEG-Hb; Group IV (n = 10) were preserved by cold ischemic storage for 4 hours at 4 degrees C; and Group V (n = 10) were tested after fresh extirpation. Left ventricular (LV) function was measured in the nonworking state at 15 minute, 1 hour, and 2 hour intervals after transfer to a standard crystalloid Langendorff circuit. Developed LV pressure at 0.5 ml LV volume was superior in Group II at early time points, yet it was similar in all preserved groups at 2 hours. +dP/dt(max) at 0.5 ml LV volume was consistent at all time points and greater in PEG-Hb preserved groups compared with Group V. -dP/dt(max) at 0.5 ml LV volume was significantly greater in Groups II and III compared with Group V initially (p < 0.05), but all were similar at the end of testing. Continuous perfusion preservation of rabbit hearts for time increments up to 24 hours with this novel PEG-Hb solution at 30 mm Hg and 20 degrees C yields LV function that is similar to 4 hours of ischemic hypothermic storage. Extended cardiac perfusion preservation with this PEG-Hb solution deserves further investigation in large animal transplant models.