Enhanced regeneration in injured sciatic nerve by human amniotic mesenchymal stem cell.

OBJECTIVE: Amniotic fluid mesenchymal stem cells (MSCs) have the potential to differentiate into neuronal stem cells in vitro. We evaluated using amniotic fluid MSCs to support or enhance the ability of the injured sciatic nerve to cross a nerve gap. MATERIALS AND METHODS: We created a 5 mm nerve defect in Sprague Dawley rats. One group received therapy with MSCs embedded into woven oxidised regenerated cellulose gauze (Surgical; Ethicon, Somerville, NJ) and fibrin glue, while a control group received woven Surgicel and fibrin glue only. Evaluation methods included behavioural, electrophysiological and immunohistochemical studies. RESULTS: In gait analysis, the angle of the ankles in the treatment and control group were 46.4 degrees (standard deviation [SD]=15 degrees) and 36 degrees (SD=8.2 degrees), respectively, which was statistically significant (p=0.045). Five of 10 treated rats (50%) demonstrated partial foot movement, while none of the control group had any movement. The percentage amplitude of muscle compound action potential in the experimental group was 43% (SD=12.5%) compared to 29% (SD=8.8%) in the control group (p=0.038). The conduction latencies in the control and experimental groups was 2.5 ms (SD=0.45) and 1.7 ms (SD=0.47), respectively (p=0.005). Histological examination demonstrated that 70% of the treatment group achieved a maximum axon diameter percentage across the nerve gap of greater than 50%, compared with 0% in the control group. There were no differences in direction of fibre growth and fibrotic reaction between the two groups. CONCLUSION: Amniotic fluid MSC can augment growth of injured nerve across a nerve gap. This effect may be due to neurotrophic or induction effects of the MSC interacting with Schwann cells. Further study is required to determine the underlying mechanism of this effect.     

细胞移植治疗脊髓损伤（英文）

Spinal cord injury can lead to severe motor,sensory and autonomic dysfunction.Currently,there is no effective treatment for the injured spinalcord.The transplantation of Schwann cells,neural stem cells or progenitor cells,olfactory ensheathing cells,oligodendrocyte precursor cells and mesenchymal stem cells has been investigated as potential therapies for spinal cord injury.However,little is known about the mechanisms through which these individual cell types promote repair and functional improvements.The five most commonly proposed mechanisms include neuroprotection,immunomodulation,axon regeneration,neuronal relay formation and myelin regeneration.A better understanding of the mechanisms whereby these cells promote functional improvements,as well as an appreciation of the obstacles in implementing these therapies and effectively modeling spinal cord injury,will be important to make cell transplantation a viable clinical option and may lead to the development of more targeted therapies.     

Adult neural progenitor cell grafts survive after acute spinal cord injury and integrate along axonal pathways

The main rationale for cell-based therapies following spinal cord injury are: (i) replacement of degenerated spinal cord parenchyma by an axon growth supporting scaffold; (ii) remyelination of regenerating axons; and (iii), local delivery of growth promoting molecules. A potential source to meet these requirements is adult neural progenitor cells, which were examined in the present study. Fibroblast growth factor 2-responsive adult spinal cord-derived syngenic neural progenitor cells were either genetically modified in vitro to express green fluorescent protein (GFP) using retroviral vectors or prelabelled with bromodeoxyuridine (BrdU). Neural progenitor cells revealed antigenic properties of neurons and glial cells in vitro confirming their multipotency. This differentiation pattern was unaffected by retroviral transduction. GFP-expressing or BrdU-prelabelled neural progenitor cells were grafted as neurospheres directly into the acutely injured rat cervical spinal cord. Animals with lesions only served as controls. Three weeks postoperatively, grafted neural progenitor cells integrated along axonal profiles surrounding the lesion site. In contrast to observations in culture, grafted neural progenitor cells differentiated only into astro- and oligodendroglial lineages, supporting the notion that the adult spinal cord provides molecular cues for glial, but not for neuronal, differentiation. This study demonstrates that adult neural progenitor cells will survive after transplantation into the acutely injured spinal cord. The observed oligodendroglial and astroglial differentiation and integration along axonal pathways represent important prerequisites for potential remyelination and support of axonal regrowth.     

Gene transfer of glial cell line-derived neurotrophic factor promotes functional recovery following spinal cord contusion

Neuronal cell death and the failure of axonal regeneration cause a permanent functional deficit following spinal cord injury (SCI). Administration of recombinant glial cell line-derived neurotrophic factor (GDNF) has previously been reported to rescue neurons following severe SCI, resulting in improved hindlimb locomotion in rats. In this study, thus, GDNF gene therapy using an adenoviral vector (rAd-GDNF) was examined in rats following SCI induced by dropping the NYU weight-drop impactor from a height of 25 mm onto spinal segment T9-T10. To evaluate the efficacy of intraspinal injection of recombinant adenovirus into the injured spinal cord, we observed green fluorescent protein (GFP) gene transfer in the contused spinal cord. GFP was effectively expressed in the injured spinal cord, and the most prominently transduced cells were astrocytes. The expression of GDNF was detected only in rats receiving rAd-GDNF, not the controls, and remained detectable around the injured site for at least 8 days. Open-field locomotion analysis revealed that rats receiving rAd-GDNF exhibited improved locomotor function and hindlimb weight support compared to the control groups. Immunohistochemical examination for the neuronal marker, calcitonin gene-related peptide (CGRP), showed an increase in CGRP+ neuronal fibers in the injured spinal cord in rats receiving rAd-GDNF treatment. Collectively, the results suggest that adenoviral gene transfer of GDNF can preserve neuronal fibers and promote hindlimb locomotor recovery from spinal cord contusion. This research should provide information for developing a clinical strategy for GDNF gene therapy.     

自体骨髓干细胞移植治疗脊髓损伤420例

目的：总结分析骨髓干细胞移植治疗脊髓损伤的效果。 方法：2003-09/2008-04解放军第四六三医院神经外科细胞治疗康复中心行干细胞移植的脊髓损伤患者420例,按病情分为2组：完全性脊髓损伤组42例,不完全性脊髓损伤组378例,两组患者在性别、年龄、受伤时间、损伤部位、损伤原因等方面比较差异无显著性意义(P > 0.05)。两组首先通过手术或立体定向的方法把干细胞直接移植在脊髓损伤部位,然后再根据患者病情经腰穿途径或经静脉途径移植,每次移植间隔为1周,干细胞移植量为(2~3)个×102/kg。移植过程中为促进干细胞的生长和分化,根据患者病情及身体状况给予相应的康复功能锻炼。 结果：与入院时比较,骨髓干细胞移植1,3,12个月后,不完全性脊髓损伤患者针刺觉评分、轻触觉评分、运动评分均有明显改善(P < 0.05或0.01),完全性脊髓损伤患者针刺觉评分、轻触觉评分、运动评分均无明显变化(P > 0.05),两组残损分级均无明显改善(P > 0.05)。 结论：骨髓干细胞移植治疗脊髓损伤有效可行。     

Optimal time for subarachnoid transplantation of neural progenitor cells in the treatment of contusive spinal cord injury

This study aimed to identify the optimal neural progenitor cell transplantation time for spinal cord injury in rats via the subarachnoid space. Cultured neural progenitor cells from 14-day embryonic rats, constitutively expressing enhanced green fluorescence protein, or media alone, were injected into the subarachnoid space of adult rats at 1 hour (acute stage), 7 days (subacute stage) and 28 days (chronic stage) after contusive spinal cord injury. Results showed that grafted neural progenitor cells migrated and aggregated around the blood vessels of the injured region, and infiltrated the spinal cord parenchyma along the tissue spaces in the acute stage transplantation group. However, this was not observed in subacute and chronic stage transplantation groups. O4- and glial fibrillary acidic protein-positive cells, representing oligodendrocytes and astrocytes respectively, were detected in the core of the grafted cluster attached to the cauda equina pia surface in the chronic stage transplantation group 8 weeks after transplantation. Both acute and subacute stage transplantation groups were negative for O4 and glial fibrillary acidic protein cells. Basso, Beattie and Bresnahan scale score comparisons indicated that rat hind limb locomotor activity showed better recovery after acute stage transplantation than after subacute and chronic transplantation. Our experimental findings suggest that the subarachnoid route could be useful for transplantation of neural progenitor cells at the acute stage of spinal cord injury. Although grafted cells survived only for a short time and did not differentiate into astrocytes or neurons, they were able to reach the parenchyma of the injured spinal cord and improve neurological function in rats. Transplantation efficacy was enhanced at the acute stage in comparison with subacute and chronic stages.     

Granulocyte colony-stimulating factor attenuates neuronal death and promotes functional recovery after spinal cord injury in mice

Granulocyte colony-stimulating factor (G-CSF) is a protein that stimulates differentiation, proliferation, and survival of granulocytic lineage cells. Recently, a neuroprotective effect of G-CSF was reported in a model of cerebral infarction. The aim of the present study was to elucidate the potential therapeutic effect of G-CSF for spinal cord injury (SCI) in mice. We found that G-CSF is neuroprotective against glutamate-induced cell death of cerebellar granule neurons in vitro. Moreover, we used a mouse model of compressive SCI to examine the neuroprotective potential of G-CSF in vivo. Histologic assessment with cresyl violet staining revealed that the number of surviving neurons in the injured spinal cord was significantly increased in G-CSF-treated mice. Immunohistochemistry for neuronal apoptosis revealed that G-CSF suppressed neuronal apoptosis after SCI. Moreover, administration of G-CSF promoted hindlimb functional recovery. Examination of signaling pathways downstream of the G-CSF receptor suggests that G-CSF might promote functional recovery by inhibiting neuronal apoptosis after SCI. G-CSF is currently used in the clinic for hematopoietic stimulation, and its ongoing clinical trial for brain infarction makes it an appealing molecule that could be rapidly placed into trials for patients with acute SCI.     

A New Surgical Technique That Allows Proximodistal Regeneration of 5-HT Fibers after Complete Transection of the Rat Spinal Cord

Shortening of the spinal column has been regarded as one possible method to obtain cord-to-cord apposition after total transection of the spinal column. However, to further improve regenerative possibilities, the problems of inconstant bony fusion and cyst formations within the junctions must be resolved. Modifying the method of de Medinaceli on the rat thoracic spine, we attempted several fixation devices to achieve better interspinal fixation after spondylectomy and transection, including transpedicular miniscrews, wiring of the transverse processes, and wiring of the posterior spinal processes. A dynamic model, based on retracting and compressing the cut ends of the spinal cord by means of adjustable fixation devices to allow swelling and shrinking of the stumps was also attempted to better compensate pathophysiologic changes of the transected cord. The best regeneration, as indicated by regrowth of 5-HT fibers below the level of transection, was obtained following application of fibrin glue and compressive wiring of posterior spinal processes. In this group, the distance between proximal and distal GFAP-rich spinal cord tissue (gap consisting of GFAP-poor components such as cysts, phagocytic cells, and scar tissue) of the two spinal cord stumps was also the shortest. With better approximation, the numbers of regenerated 5-HT fibers improved remarkably, suggesting that this descending fiber system is able to bridge the transection under these conditions.     

Implantation of dendritic cells in injured adult spinal cord results in activation of endogenous neural stem/progenitor cells leading to de novo neurogenesis and functional recovery

We report a treatment for spinal cord injury involving implantation of dendritic cells (DCs), which act as antigen-presenting cells in the immune system. The novel mechanisms underlying this treatment produce functional recovery. Among the immune cells tested, DCs showed the strongest activity inducing proliferation and survival of neural stem/progenitor cells (NSPCs) in vitro. Furthermore, in DC-implanted adult mice, endogenous NSPCs in the injured spinal cord were activated for mitotic de novo neurogenesis. These DCs produced neurotrophin-3 and activated endogenous microglia in the injured spinal cord. Behavioral analysis revealed the locomotor functions of DC-implanted mice to have recovered significantly as compared to those of control mice. Our results suggest that DC-implantation exerts trophic effects, including activation of endogenous NSPCs, leading to repair of the injured adult spinal cord.     

组织工程支架在犬急性脊髓损伤修复中应用的初步研究

目的探讨携带神经干细胞的聚碳酸亚丙酯[poly（propylene carbonate），PPC]可降解支架移植在犬脊髓急性损伤后修复中的作用。方法制作犬T13脊髓左侧半切损伤模型。将实验动物随机分为3组：细胞支架组在损伤后1周时将填充神经干细胞的PPC可降解支架植入损伤区．支架组只植入支架，对照组不作移植。8周后观察支架的组织反应、降解情况及神经干细胞的迁移分化和脊髓轴突再生情况。结果支架部分降解，管腔内未见瘢痕侵入。神经干细胞向支架邻近部位广泛迁移、扩散，并分化为3种神经细胞表型。神经丝蛋白（NF）及髓鞘碱性磷酯蛋白（MBP）免疫组化显示细胞支架组脊髓损伤区邻近部位的继发损害较其他组轻。结论携带神经干细胞的PPC可降解支架在犬脊髓组织中无明显组织反应．能够抵御瘢痕侵入：其携带的神经干细胞能够整合入邻近脊髓组织并起到一定保护作用。     

损伤脊髓匀浆上清对骨髓间充质干细胞分泌髓鞘前脂蛋白、脑源性神经营养因子的影响

背景：损伤脊髓匀浆上清成分复杂,其中不仅存在多种化学物质,而且也存在着多种细胞因子,这些物质能否影响骨髓间充质干细胞的增殖分化和分泌功能还不清楚。 目的：探讨损伤脊髓匀浆上清成分对骨髓间充质干细胞分泌的脑源性神经营养因子和髓鞘前脂蛋白的影响。 方法：贴壁法分离纯化Wistar大鼠骨髓间充质干细胞,稳定传到第3代后,分别用正常和损伤的Wistar大鼠脊髓匀浆上清诱导培养20 d。免疫荧光染色检测神经元特异性烯醇化酶阳性细胞,ELISA法检测培养液内髓鞘前脂蛋白、脑源性神经营养因子的含量,即时定量-PCR检测髓鞘前脂蛋白mRNA、脑源性神经营养因子mRNA水平。 结果与结论：损伤脊髓匀浆上清液诱导培养骨髓间充质干细胞后,神经元特异性烯醇化酶阳性细胞率和培养液内脑源性神经营养因子、髓鞘前脂蛋白的含量在各个时间点均较正常脊髓匀浆上清液对骨髓间充质干细胞培养组高。提示,损伤的脊髓匀浆上清液能够诱导骨髓间充质干细胞分泌脑源性神经营养因子、髓鞘前脂蛋白,有利于向神经细胞方向分化。     

Effect of bone marrow-derived mononuclear cells on nerve regeneration in the transection model of the rat sciatic nerve

Bone marrow-derived stem cells enhance the rate of regeneration and clinical improvement in nerve injury, spinal cord injury and brain infarction. Recent experiments in rat spinal cord demyelination showed that remyelination was specific to intravenous delivery of the bone marrow-derived mononuclear cell (BM-MNC) fraction, although the specific role of this fraction in peripheral nerve regeneration has not been examined. Therefore we evaluated the role of BM-MNCs in peripheral nerve regeneration in the rat sciatic nerve transection model. After anesthesia, the right sciatic nerve of 20 adult-male Wistar rats was transected under an operating microscope. In the test group, the cut ends of the nerve were approximated with two epineural microsutures, the gap was filled with rat BM-MNCs and the approximated nerve ends were covered with fibrin glue. In the control group, the transected nerve ends were repaired with two epineural microsutures and fibrin sealant only. Histological assessment of the nerve was performed 30 days and 60 days after the operation and regenerative changes were compared between the two groups. The recovery after nerve anastamosis was far better in the test group at both 30 days and 60 days. There was a statistically significant difference in axonal regeneration, remyelination and myelin thickness at sites 5 mm and 10 mm from the site of repair of the nerve. Schwann cell proliferation and degenerative changes were more prevalent in the controls. This study demonstrates that local delivery of BM-MNCs (which can be isolated easily from bone marrow aspirates) into injured peripheral nerve increases the rate and degree of nerve regeneration. The present study highlights the role of BM-MNCs in peripheral nerve regeneration.     

Induced pluripotent stem cell-derived neural stem cell therapies for spinal cord injury

The greatest challenge to successful treatment of spinal cord injury is the limited regenerative capacity of the central nervous system and its inability to replace lost neurons and severed axons following injury. Neural stem cell grafts derived from fetal central nervous system tissue or embryonic stem cells have shown therapeutic promise by differentiation into neurons and glia that have the potential to form functional neuronal relays across injured spinal cord segments. However, implementation of fetal-derived or embryonic stem cell-derived neural stem cell therapies for patients with spinal cord injury raises ethical concerns. Induced pluripotent stem cells can be generated from adult somatic cells and differentiated into neural stem cells suitable for therapeutic use, thereby providing an ethical source of implantable cells that can be made in an autologous fashion to avoid problems of immune rejection. This review discusses the therapeutic potential of human induced pluripotent stem cell-derived neural stem cell transplantation for treatment of spinal cord injury, as well as addressing potential mechanisms, future perspectives and challenges.     

Distribution of transferrin receptors in relation to cytochrome oxidase activity in the human spinal cord, lower brainstem and cerebellum.

Neuronal activity and oxidative energy metabolism are tightly coupled. There is evidence that cytochrome oxidase, the terminal enzyme of the electron transport chain, can serve as a metabolic marker of neuronal activity. All the respiratory chain enzymes have iron containing prosthetic groups and therefore represent an important component of iron utilisation. Since iron entry into cells is mediated by the transferrin receptor, this receptor may also serve as marker of neuronal activity. The histochemical distribution of cytochrome oxidase has therefore been compared with the autoradiographic distribution of the transferrin receptor in the human spinal cord, brainstem and cerebellum. Cytochrome oxidase activity showed a very similar pattern of distribution to the transferrin receptor in the spinal cord, brainstem and cerebellum. The highest levels of cytochrome oxidase activity and transferrin receptor binding were associated with; in the spinal cord, the substantia gelatinosa, laminae II and III and the motor neurones; in the medulla and pons, the spinal trigeminal nucleus, hypoglossal nucleus, dorsal motor nucleus of the vagus, inferior and superior olives, nucleus praepositus, nucleus paramedianus, central grey, superior central nuclei and locus coeruleus; in the cerebellum, the molecular layer. The results suggest that the transferrin receptor may provide a useful marker of total neuronal respiratory activity.     

骨髓间充质干细胞尾静脉移植脊髓损伤大鼠脑源性神经营养因子及神经生长因子的表达

背景：骨髓间充质干细胞移植对脊髓损伤有治疗作用,但其机制尚不完全清楚。 目的：应用免疫组织化学方法观察骨髓间充质干细胞静脉移植损伤脊髓局部脑源性神经营养因子及神经生长因子的表达,分析骨髓间充质干细胞移植治疗大鼠脊髓损伤的作用途径。 方法：运用改良Allen法制备T10脊髓外伤性截瘫大鼠模型,假手术组6只,脊髓损伤组24只随机分为对照组和骨髓间充质干细胞移植组。骨髓间充质干细胞移植组、假手术组接受骨髓间充质干细胞单细胞悬液1 mL(1×106 cells)自大鼠尾静脉缓慢注射移植,对照组静脉注射PBS 1 mL。 结果与结论：脊髓损伤后损伤局部的脑源性神经营养因子、神经生长因子表达增加,骨髓间充质干细胞静脉注射移植后能促进脊髓损伤局部脑源性神经营养因子、神经生长因子更进一步的表达,这可能是促进神经结构及神经功能恢复的因素之一。     

生物蛋白胶复合骨髓间充质干细胞修复兔多层软组织缺损

背景：符合软组织生理结构的生物蛋白胶适合作为修复软组织缺损的载体材料。 目的：观察生物蛋白胶复合骨髓间充质干细胞修复软组织缺损的可行性。 方法：在新西兰大白兔大腿处造成深达肌肉层,直径大于3 cm的软组织缺损。将24只新西兰大白兔随机分为3组,实验组将同种异体来源的骨髓间充质干细胞复合生物蛋白胶注射到软组织缺损处,对照组将生物蛋白胶注射到软组织缺损处,模型组造模后不注射。 结果与结论：术后14,21 d创面收缩率,实验组>对照组>模型组(P < 0.01);愈合时间,实验组<对照组<模型组(P < 0.01)。结果显示以生物蛋白胶为载体复合骨髓间充质干细胞能快速的修复多层软组织缺损。     

周围神经联合生长因子移植治疗急性脊髓损伤

背景：目前促进神经再生与修复的策略也主要是通过促进神经内在的再生能力和改善再生的微环境两大途径,已有的研究表明联合应用一些治疗手段能更好地促进神经轴突的再生生长。 目的：探讨周围神经联合生长因子移植治疗大鼠脊髓损伤的可行性及效果。 方法：健康成年雌性SD大鼠60只,随机数字表法分为4组：神经移植组、神经移植联合生长因子组、脊髓横断组、椎板切除组。以T9为中心纵行切开大鼠皮肤,显露硬膜囊,水平切断脊髓并切除3mm,神经移植组、神经移植联合生长因子组取双侧第8~10对肋间神经各2 cm,将自体肋间神经修剪成合适长度后交叉移植入脊髓缺损处(近端白质与远端灰质、远端白质与近端灰质),神经移植组用纤维蛋白凝胶固定植入的肋间神经,神经移植联合生长因子组用含有2.1 mg/L 酸性成纤维细胞生长因子的纤维蛋白凝胶固定植入的肋间神经,缝合硬膜。脊髓横断组断端间旷置,椎板切除组仅行椎板切除术。术后90 d进行体感及运动诱发电位检测,术后70 d进行Basso.Beattie.Bresnahan(BBB)后肢运动功能评分。 结果与结论：椎板切除组均引出了体感及运动诱发电位;脊髓横断组未引出体感及运动诱发电位波形;神经移植组3只引出双侧体感诱发电位,4只引出单侧体感诱发电位,4只引出双侧运动诱发电位,3只引出单侧运动诱发电位,神经移植联合生长因子组5只引出双侧体感诱发电位,2只引出单侧体感诱发电位,神经移植联合生长因子组5只引出双侧运动诱发电位,2只引出单侧运动诱发电位。神经移植组、神经移植联合生长因子组大鼠体感及运动诱发电位潜伏期及波幅明显优于脊髓横断组(P < 0.01),自体肋神经移植联合生长因子组优于神经移植组(P < 0.01)。椎板切除组大鼠麻醉清醒后运动恢复正常, 脊髓横断组在3个月的生存期内后肢持续伸展、旋转,神经移植组和神经移植联合生长因子组大鼠后肢功能术后3周开始明显恢复,并在整个观察期内逐渐恢复。神经移植组和神经移植联合生长因子组BBB后肢运动功能评分较脊髓横断组明显提高(P < 0.01),并且神经移植联合生长因子组较神经移植组高(P < 0.01)。提示单纯周围神经移植能部分恢复脊髓功能,联合生长因子则能更好地恢复脊髓功能。     

Endothelial progenitor cell-conditioned medium promotes angiogenesis and is neuroprotective after spinal cord injury

Endothelial progenitor cells secrete a variety of growth factors that inhibit inflammation, promote angiogenesis and exert neuroprotective effects. Therefore, in this study, we investigated whether endothelial progenitor cell-conditioned medium might have therapeutic effectiveness for the treatment of spinal cord injury using both in vitro and in vivo experiments. After primary culture of bone marrow-derived macrophages, lipopolysaccharide stimulation was used to classically activate macrophages to their proinflammatory phenotype. These cells were then treated with endothelial progenitor cell-conditioned medium or control medium. Polymerase chain reaction was used to determine mR NA expression levels of related inflammatory factors. Afterwards, primary cultures of rat spinal cord neuronal cells were prepared and treated with H_2O_2 and either endothelial progenitor cell-conditioned medium or control medium. Hoechst 33258 and propidium iodide staining were used to calculate the proportion of neurons undergoing apoptosis. Aortic ring assay was performed to assess the effect of endothelial progenitor cell-conditioned medium on angiogenesis. Compared with control medium, endothelial progenitor cell-conditioned medium mitigated the macrophage inflammatory response at the spinal cord injury site, suppressed apoptosis, and promoted angiogenesis. Next, we used a rat model of spinal cord injury to examine the effects of the endothelial progenitor cell-conditioned medium in vivo. The rats were randomly administered intraperitoneal injection of PBS, control medium or endothelial progenitor cell-conditioned medium, once a day, for 6 consecutive weeks. Immunohistochemistry was used to observe neuronal morphology. Terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay was performed to detect the proportion of apoptotic neurons in the gray matter. The Basso, Beattie and Bresnahan Locomotor Rating Scale was used to evaluate the recovery of motor function of the bilateral hind limbs after spinal cord injury. Compared with the other two groups, the number of axons was increased, cavities in the spinal cord were decreased, the proportion of apoptotic neurons in the gray matter was reduced, and the Basso, Beattie and Bresnahan score was higher in the endothelial progenitor cell-conditioned medium group. Taken together, the in vivo and in vitro results suggest that endothelial progenitor cell-conditioned medium suppresses inflammation, promotes angiogenesis, provides neuroprotection, and promotes functional recovery after spinal cord injury.     

野百合碱诱导大鼠肺动脉高压模型的建立

背景：目前尚缺乏简单易行、实用、操作性强的肺动脉高压动物模型。 目的：建立一种实用的注射野百合碱诱导的肺动脉高压动物模型。 方法：采用一次性皮下注射野百合碱60 mg/kg的方法制备SD大鼠肺动脉高压模型。 结果与结论：野百合碱注射后第1,2,3,4周,大鼠平均肺动脉压明显升高,右心室肥厚明显。光镜下可见肺小血管肌化程度增强,相对中膜厚度增加,肺血管密度减少,以上症状均随野百合碱注射时间的延长逐渐加重。证实此方法建立的大鼠肺动脉高压模型造模成功。     

Hematopoietic stem cell and marrow stromal cell for spinal cord injury in mice

We compared the effects of hematopoietic stem cell and marrow stromal cell transplantation for spinal cord injury in mice. From green fluorescent protein transgenic mouse bone marrow, lineage-negative, c-kit- and Sca-1-positive cells were sorted as hematopoietic stem cells and plastic-adherent cells were cultured as marrow stromal cells. One week after injury, hematopoietic stem cells or marrow stromal cells were injected into the lesioned site. Functional recovery was assessed and immunohistochemistry was performed. In the hematopoietic stem cell group, a portion of green fluorescent protein-positive cells expressed glial marker. In the marrow stem cell group, a number of green fluorescent protein and fibronectin-double positive cells were observed. No significant difference was observed in the recovery between both groups. Both hematopoietic stem cells and marrow stromal cells have the potential to restore the injured spinal cord and to promote functional recovery.