Myeloid regeneration after bone-marrow transplantation monitored by serum measurements of myeloperoxidase, lysozyme and lactoferrin

Bone-marrow regeneration after chemo- and radiotherapy-induced aplasia can be monitored by serum levels of myeloperoxidase (MPO), lysozyme (LYS) and lactoferrin (LF). In 10 patients with leukemia, serum measurements were performed before and after bone-marrow transplantation. Bone-marrow regeneration was suggested by increments in serum MPO and LYS 5 and 4 days prior to the increase in mononuclear cells (Mono) and 10 and 9 d before the increase in polymorphonuclear leukocytes (PMN) in the peripheral blood. LF started to rise 4.5 d before detectable circulating PMNs. 2 patients with early relapses of leukemia post transplantation are shown to display atypical patterns of serum MPO and LYS. We conclude that serum measurements of MPO, LYS and LF may be used as early and sensitive means to monitor bone-marrow activity during hematological regeneration. However, the findings also strongly support the earlier proposal that MPO alone may be used to reflect myeloid activity in the bone-marrow in general.     

Chemical traumatization of adult mouse olfactory epithelium in situ stimulates growth and differentiation of olfactory neurons in vitro

This study demonstrates that ZnSO₄ induced chemical trauma results in an in situ regeneration of the olfactory epithelium which, when maintained in vitro, provides an enriched population of olfactory neurons. Therefore, the ability of the olfactory epithelium to respond to chemical trauma with increased mitotic activity can be used to increase growth of neurons in culture. Tissue obtained from normal or vehicle-treated adult mice produced few olfactory neurons, when maintained in culture, compared to cultures established from tissue following an in situ ZnSO₄ trauma. Maximal neuronal yields were obtained in cultures established from tissue that was removed 4–6 days following chemical trauma. The morphological appearance and the presence of cell specific intermediate filament proteins were used to classify the cell types in these olfactory epithelial cultures. Single cells and aggregates of cells which were immunopositive for keratin, but immunonegative for neurofilament protein and GFAP, were identified as epithelioid. Flattened polygonal cells immunopositive for GFAP were identified as glia. A small population of flattened cells was immunonegative for all of the antibodies used in this study. Cells that had processes were immunonegative for GFAP and keratin. Some were immunopositive for 200 kDa and 160 kDa neurofilament proteins but immunonegative for the 68 kDa neurofilament protein. A few of these cells showed positive immunoreactivity with the olfactory marker protein (OMP) antibody and most likely represented the most mature olfactory neurons in the cultures. This trauma-induced culture model using olfactory tissue from adult mice can serve as a source of CNS neurons for comparison with cultured embryonic neurons.     

Research review: DNA polymerases as molecular markers of the regenerating capacity of hepatocytes

Hepatocyte regeneration has been widely investigated, with the mitotic index and the incorporation of [³H]thymidine being used as regeneration markers. We focused on the induction of DNA replication enzymes, particularly DNA polymerases (pol) α, δ, and ε. Using rat models, we have shown that the activity of pol α in crude liver extract well represents the regenerating capacity of hepatocytes. Using pol α as an indicator, we analyzed liver regeneration in rat models under various conditions: obstructive jaundice, external or internal biliary drainage, and the obstruction of portal vein branches. It has been revealed that the ligation of the common bile duct alone induces a certain amount of hepatocyte proliferation. It was striking that external biliary drainage suppressed regeneration capacity in cholestatic rat liver after partial hepatectomy. The strong regeneration in nonligated lobes induced by portal branch ligation was similar to the liver regeneration seen after partial hepatectomy with respect to the induction of DNA polymerases. Taken together, the aspects of DNA replication, particularly the induction of DNA polymerases, may contribute to shedding new light on the regeneration of human liver. This work was supported in part by a Grant-in-Aid for General Scientific Research and for Cancer Research from the Ministry of Education, Science and Culture, Japan, and by grants from the Uehara Memorial Foundation     

Study of nerve regeneration in centrocentral anastomosis

Summary Nerve regeneration was studied in a model of centrocentral anastomosis (CCA) performed on the sciatic nerve of the rat. Experimental CCA was made by suturing the proximal end of the peroneal branch on the proximal end of the sural branch, placing between them a peroneal nerve graft (Group I, 20 rats) or a silicone chamber (Group II, 12 rats). Nerve grafts had a length of 5mm and silicone chambers 7 mm. In six silicone chambers an 1 mm nerve graft was placed in the centre of the tube. In group I animals anterograde degeneration was studied by cutting the graft 60 days after surgery. In group II, nerve regeneration was studied 2, 4 and 8 weeks after surgery. Results indicate that in CCA: 1) regenerated axons coming from one nerve end grow into the graft but do not cross the contralateral suture line; 2) regeneration is poorer in silicone chambers than in nerve grafts; and, 3) in silicone chambers regeneration is related to time. The reduction in the regenerative capability in CCA seems to be related to the alteration of nerve sprouts aiming for the peripheral targets.     

Comparative effects of plateletderived growth factor-BB and insulin-like growth factor-I, individually and in combination, on periodontal regeneration in Macaca fascicularis

Platelet-derived growth factor (PDGF) and insulin-like growth factor I (IGF-I) in combination have previously been shown to enhance periodontal regeneration. The objective of this study was to further characterize the biological effects of this combination of growth factors in non-human primates and compare the effects to those of each growth factor individually. Ligature-induced periodontitis was initiated in 10 cynomolgus monkeys. After periodontal lesions were established, surgery was performed, and either a methylcellulose gel vehicle or vehicle containing 10 μg each of either PDGF-BB, IGF-I or both PDGF-BB and IGF-I was applied to exposed root surfaces. Biopsies were taken 4 and 12 wk after treatment and the extent of periodontal regeneration was assessed by histomorphometry. At both 4 and 12 wk vehicle-treated lesions generally revealed minimal osseous defect fill (ODF) (8.5±2.1% and 14.5±5.7%, respectively) and new attachment (NA) (34.1±5.2% and 26.6±10.5%, respectively). IGF-I treatment did not significantly alter healing compared to vehicle in any parameter at both 4 and 12 wk. PDGFBB-treated sites exhibited significant (p<0.05) regeneration of NA (69.6±12.0%) at 12 wk; trends for PDGF-BB treatment effect were also observed in other parameters at 4 and 12 wk. although these increases were not statistically significant. Treatment with PDGF-BB/IGF-I resulted in 21.6±5.1 % and 42.5±8.3% ODF at 4 and 12 wk, respectively, and 64.1±7.7% and 74.6±7.4% NA at 4 and 12 wk, respectively (all significantly greater than vehicle, p<0.05). The results from this study demonstrated that: 1) IGF-1 alone at the dose tested did not significantly alter periodontal wound healing; 2) PDGF-BB alone significantly stimulated NA, with trends of effect on other parameters; and 3) the PDGF-BB/IGF-I combination resulted in significant increases in NA and ODF above vehicle at both 4 and 12 wk.     

体外培养诱导外周血淋巴细胞促进大鼠面神经再生的实验研究

目的:通过在神经缺损处局部回输体外分离培养纯化的淋巴细胞,了解此种方法促进面神经损伤修复的效果。方法:将20只Wistar大鼠的面神经颊支剪断并立即缝合(其余3支反折缝合)制成面神经损伤模型大鼠,将其分成淋巴细胞组和对照组,每组10只,每组再分成2周组和8周组。淋巴细胞组局部回输体外分离培养的外周血淋巴细胞,对照组作对照。于2周和8周测定面神经颊支-触须肌复合动作电位传导速度,辣根过氧化物酶(HRP)神经逆行示踪测定面神经核团的神经元阳性数目。结果:淋巴细胞组面神经颊支-触须肌复合动作电位传导速度8周时为0.64±0.07,与对照组(0.56±0.07)相比,差异有统计学意义(P<0.05)。HRP神经逆行示踪测定面神经核团神经元阳性数目,淋巴细胞组2周及8周与对照组同时间段相比差异均无统计学意义(均P>0.05)。结论:体外分离培养纯化的淋巴细胞在局部应用于神经损伤处对面神经再生修复可起一定的促进作用。     

重视神经、内分泌与免疫机制在皮肤修复与再生中作用的研究

目的概述神经、内分泌与免疫学机制的变化对皮肤修复的影响,以及近年来的研究进展,为深入开展这一领域的研究和临床治疗提供依据.方法广泛阅读国内外相关文献,并进行分析、综合,确定神经、内分泌与免疫机制在皮肤修复中的作用.结果皮肤作为神经依赖性器官、内分泌器官及免疫器官,在皮肤损伤修复与再生中发挥重要作用.结论目前对这一领域研究较少,应加强相关基础研究.     

大网膜包裹人工神经移植体再血管化及神经再生的研究

目的 探讨大网膜包裹人工神经移植体的早期再血管化，以及增强移植体血供对神经再生的影响。方法 75只大耳白兔制作成左前肢正中神经2．0cm缺损，随机分成3组：A组，带蒂大网膜包裹人工神经移植体移植；B组，人工神经移植体桥接神经缺损；C组，自体神经桥接神经缺损，作为对照组。术后3、7和14d应用伊凡思蓝（evans blue bound to albumin，EBA）毛细血管造影，检测各组移植体的再血管化；术后12周通过电生理、光镜、透射电镜等检测评估神经再生的效果。结果 A、C组术后3d移植神经出现再血管化，7d和14d再血管化程度逐渐增强；B组7d出现再血管化，与A、C组比较，再血管化延迟。术后12周，A组和C组运动神经传导速度、有髓神经纤维密度、神经内纤维组织面积及面积比、髓鞘厚度、髓鞘直径等差异无统计学意义（P〉0．05），但均优于B组，差异有统计学意义（P〈0．05）。结论 大网膜包裹人工神经移植体可促进移植体早期再血管化，增强移植体血供，促进神经再生。     

复合神经营养因子的神经导管研究进展

目前周围神经的组织工程研究热点之一就是研制具有生物活性的神经导管,主要方法是神经导管与雪旺细胞或者神经营养因子相结合来促进周围神经的再生。就复合神经营养因子的神经导管的相关研究进展作一综述。     

自体移植脾组织VEGF、KDR表达与血管再生的实验研究

目的 研究自体移植脾组织血管再生及VEGF、KDR表达规律，阐明VEGF、KDR对移植脾组织血管再生的调控作用，为脾脏外科临床及实验研究提供理论依据。方法 健康Wistar大鼠70只，体重100—120g，随机分为7组，每组10只中又设脾切除自体脾移植组5只，假手术组5只，分别于术后7，14，30，60，90，120，180d进行：(1)自体移植脾组织病理学检测；(2)大鼠行主动脉插管灌注墨汁，光镜观测再生血管并采用图像分析测定其密度；(3)免疫组化抗VEGF、KDR抗体染色，图像分析定量，阐明其表达规律及与血管再生的关系。结果 (1)自体脾组织移植术后7d即有血管从大网膜向脾组织内伸展，移植脾组织内血管密度逐渐增大，至术后180d血管再生接近正常；(2)自体脾组织移植术后7d、14d，VEGF、KDR阳性染色细胞密度迅速升高，术后60d达高峰，以后逐渐降低，至术后180d VEGF、KDR阳性染色细胞密度趋向正常。结论 自体脾组织大网膜内移植术是简便有效的脾移植方法；移植脾组织新生血管由大网膜再生而来；术后移植脾组织内VEGF、KDR表达量升高，促进血管形成，血管再生完成后恢复正常水平。