Syngeneic transplantation with peripheral blood mononuclear cells collected after the administration of recombinant human granulocyte colony-stimulating factor

Five syngeneic transplants were performed in four patients following myeloablative therapy using unmodified peripheral blood mononuclear cells (PBMCs) collected after the administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) to normal donors. The only toxicity experienced by the four normal donors was bone pain. Four patients received two collections of PBMCs, and a second transplant was performed in one patient with one collection. The patients received a median of 20.53 x 10(8) total nucleated cells/kg (range 20 to 25.5), 11.3 x 10(8) total mononuclear cells/kg (range 6.52 to 17.2), 113.1 x 10(4)/kg CFU-GM (range 46.7 to 211.8) and 9.6 x 10(6) CD34+ cells/kg (range 1.6 to 12.6) Post-transplant growth factors were not administered. The median time to an absolute neutrophil count greater than 0.5 x 10(9)/L was 14 days (range 10 to 18). The median time to platelet transfusion independence was 11 days (range 10 to 13). Two patients had the number of CD3+ T lymphocytes determined in the pheresis product. An average of 3.04 x 10(10) CD3+ cells were collected per pheresis. This represents an approximate 1 log increase over the number of T lymphocytes in a typical bone marrow transplant. Rh-GCSF can be used to mobilize peripheral blood progenitor cells from normal donors with minimal toxicity. Studies of allogeneic transplants using PBMCs collected after rhG-CSF administration to determine permanent grafting ability and the incidence and severity of graft-versus-host disease are warranted.     

Stem cell factor retards differentiation of normal human erythroid progenitor cells while stimulating proliferation

Stem cell factor (SCF), the ligand for the c-kit tyrosine kinase receptor, markedly stimulates the accumulation of erythroid progenitor cells in vitro. We now report that SCF delays erythroid differentiation among the progeny of individual erythroid progenitors while greatly increasing the proliferation of these progeny. These effects appear to be independent of an effect on maintenance of cell viability. Highly purified day-6 erythroid colony-forming cells (ECFC), consisting mainly of colony-forming units-erythroid (CFU-E), were generated from human peripheral blood burst-forming units-erythroid (BFU-E). Addition of SCF to the ECFC in serum-free liquid culture, together with erythropoietin (EP) and insulin-like growth factor 1 (IGF-1), resulted in a marked increase in DNA synthesis, associated with a delayed peak in cellular benzidine positivity and a delayed incorporation of 59Fe into hemoglobin compared with cultures without SCF. In the presence of SCF, the number of ECFC was greatly expanded during this culture period, and total production of benzidine-positive cells plus hemoglobin synthesis were ultimately increased. To determine the effect of SCF on individual ECFC, single-cell cultures were performed in both semisolid and liquid media. These cultures demonstrated that SCF, in the presence of EP and IGF-1, acted on single cells and their descendants to delay erythroid differentiation while substantially stimulating cellular proliferation, without an enhancement of viability of the initial cells. This was also evident when the effect of SCF was determined using clones of ECFC derived from single BFU-E. Our experiments demonstrate that SCF acts on individual day-6 ECFC to retard erythroid differentiation while simultaneously providing enhanced proliferation by a process apparently independent of an effect on cell viability or programmed cell death.     

Ovine forestomach matrix biomaterial is a broad spectrum inhibitor of matrix metalloproteinases and neutrophil elastase

Proteases play a critical role in the ordered remodelling of extracellular matrix (ECM) components during wound healing and tissue regeneration. However, the usually ordered proteolysis is compromised in chronic wounds due to over‐expression and high concentrations of matrix metalloproteinase's (MMPs) and neutrophil elastase (NE). Ovine forestomach matrix (OFM) is a decellularised extracellular matrix‐based biomaterial developed for tissue regeneration applications, including the treatment of chronic wounds, and is a heterogeneous mixture of ECM proteins and proteoglycans that retains the native structural and functional characteristics of tissue ECM. Given the diverse molecular species present in OFM, we hypothesised that OFM may contain components or fragments that inhibit MMP and NE activity. An extract of OFM was shown to be a potent inhibitor of a range of tissue MMPs (IC₅₀s = 23 ± 5 to 115 ± 14 µg/ml) and NE (IC₅₀ = 157 ± 37 µg/ml), and was more potent than extracts prepared from a known protease modulating wound dressing. The broad spectrum activity of OFM against different classes of MMPs (i.e. collagenases, gelatinases and stromelysins) may provide a clinical advantage by more effectively addressing the protease imbalance seen in chronic wounds.     

Capillary transit time heterogeneity and flow-metabolism coupling after traumatic brain injury

Most patients who die after traumatic brain injury (TBI) show evidence of ischemic brain damage. Nevertheless, it has proven difficult to demonstrate cerebral ischemia in TBI patients. After TBI, both global and localized changes in cerebral blood flow (CBF) are observed, depending on the extent of diffuse brain swelling and the size and location of contusions and hematoma. These changes vary considerably over time, with most TBI patients showing reduced CBF during the first 12 hours after injury, then hyperperfusion, and in some patients vasospasms before CBF eventually normalizes. This apparent neurovascular uncoupling has been ascribed to mitochondrial dysfunction, hindered oxygen diffusion into tissue, or microthrombosis. Capillary compression by astrocytic endfeet swelling is observed in biopsies acquired from TBI patients. In animal models, elevated intracranial pressure compresses capillaries, causing redistribution of capillary flows into patterns argued to cause functional shunting of oxygenated blood through the capillary bed. We used a biophysical model of oxygen transport in tissue to examine how capillary flow disturbances may contribute to the profound changes in CBF after TBI. The analysis suggests that elevated capillary transit time heterogeneity can cause critical reductions in oxygen availability in the absence of ‘classic'' ischemia. We discuss diagnostic and therapeutic consequences of these predictions.     

PROGNOSTIC SIGNIFICANCE OF THE CO-EXPRESSION OF p53 AND c-erbB-2 PROTEINS IN BREAST CANCER

The immunohistochemical expression of p53 and c-erbB-2 gene proteins was examined in a series of 130 breast adenocarcinomas. This study intended to investigate whether the frequency of the altered expression of the tumour suppressor gene p53 and the overexpression of the oncogene c-erbB-2 in breast cancer tissue cells correlated with other variables known to affect the biological behaviour of these tumours and the overall survival of the patients (median follow-up time: 6 years). The expression of p53 protein and c-erbB-2 gene product was evaluated immunohistochemically. Expression of p53 protein was detected in 30 (23 per cent) of the neoplasms examined, while 26 (20 per cent) out of the 130 cases demonstrated positive c-erbB-2 immunoreactivity. There was a statistically significant association between p53 protein expression and primary tumour size, lymph node involvement, and oestrogen receptor positivity. The incidence of c-erbB-2 positivity was significantly correlated with high tumour grade, axillary node invasion, large tumour size, and the absence of steroid receptors. p53 immuno-expression was clearly associated with c-erbB-2 protein overexpression. Concomitant p53 and c-erbB-2 positive immunolabelling, which emerged in 14 out of the 130 cases (10·7 per cent), was clearly associated with high grade, large size, positive nodal status, ductal infiltrating (NOS) histological type, and low values of progesterone receptors. Overall survival of patients was not significantly related to the immunoreactivity of either p53 or c-erbB-2 considered separately, whereas there was a clearly significant trend to worse overall prognosis in cancers with double p53/c-erbB-2 positive phenotype. The simultaneous immunodetection of p53/c-erbB-2 appears to have greater negative prognostic relevance than their separate expression.     

不同分离方法与培养条件下大鼠骨髓间充质干细胞生长增殖情况比较

目的:应用贴壁分离法和密度梯度离心法以不同培养条件观察纯化过程中对获得的骨髓间充质干细胞的影响,试图寻找获得高质量、高活性的骨髓间充质干细胞的培养条件。方法:实验于2005-09/2006-01在解放军第四军医大学实验动物中心实验部进行。①SPF级雄性Wistar大鼠18只,贴壁分离培养取12只,根据血清和培养基的不同分为4组:进口血清 DMEM组、进口血清 F12-DMEM组、国产血清 DMEM组、国产血清 F12-DMEM组,3只/组。密度梯度离心培养实验取剩余6只,以分离液的不同分为Ficoll分离液组、Percoll分离液组,3只/组。②骨髓取材:各组大鼠断颈处死后,无菌取双下肢,剔除股骨、胫骨周围肌肉组织,剪去骨干的两端,暴露骨髓腔,穿刺两侧骨端取出骨髓。③贴壁分离法:进口血清 DMEM组、进口血清 F12-DMEM组、国产血清 DMEM组、国产血清 F12-DMEM组大鼠分别采用相应的血清和培养基冲洗骨髓,制备单细胞悬液,接种于培养瓶中,5d后首次更换培养液,弃去未贴壁细胞,此后每3～4d换液1次。④密度梯度离心法:Ficoll分离液组选用的Ficoll分离液密度为1.077;Percoll分离液组将Percoll分离液与0.1mol/L磷酸盐缓冲液按9∶1比例混匀,密度为1.073。将两组大鼠骨髓置入离心管,离心弃上清,轻轻叠加到相同体积的各自对应分离液上,再次离心收集界面层白色混浊液,采用F12-DMEM培养液重悬细胞,按1×109L-1的密度接种于培养瓶中,培养条件与贴壁分离法相同。⑤指标检测:倒置显微镜下,每天观察贴壁分离、密度梯度离心不同培养条件下细胞的生长情况和活体形态特征。进行锥虫蓝排斥试验,蓝染细胞为死亡细胞,在3min内用计数板分别计数活细胞和死细胞,未被蓝染细胞所占细胞总数的百分比即为初步得到细胞活性的数据。两种分离方法均取生长良好的第3代细胞,以时间为横坐标,细胞数为纵坐标,绘制生长曲线。结果:18只大鼠均进入结果分析。①细胞形态观察结果:贴壁分离法:采用进口血清培养的两组细胞形态学上都表现为长梭形,细胞活性较高,且给予F12-DMEM培养基的细胞增殖较快,集落融合较早,传代所需时间短;采用国产血清培养的两组细胞中,给予F12-DMEM培养基可以获得梭形细胞,而给予DMEM培养基后则多为类圆形骨髓样细胞,仅见极少梭形细胞。密度梯度离心法:Ficoll分离液组和Percoll分离液组均可培养出梭形骨髓间充质干细胞,细胞活性均高,但集落融合、传代所需的时间均较贴壁分离法长。②细胞活性检测结果:贴壁分离法:进口血清 DMEM组、进口血清 F12-DMEM组、国产血清 DMEM组、国产血清 F12-DMEM组的活细胞率分别为98.3%,98.7%,97.1%,97.7%,组间比较差异无显著性意义(χ2=0.054～0.620,P均>0.05)。密度梯度离心法:Ficoll分离液组活细胞率与Percoll分离液组相似(96.9%,97.1%,t=1.066,P>0.05)。③第3代细胞生长曲线测定结果:不同培养条件下各组第3代细胞生长曲线基本相似,在培养1d时,细胞量稍有减少;4d后细胞数均迅速增长;8d进入平台期,细胞增殖减慢。结论:采用全骨髓贴壁分离法和密度梯度离心法,只要选择合适的培养条件均可获得骨髓间充质干细胞,但选用进口胎牛血清、F12-DMEM培养基效果较好。