以海藻酸盐及异种骨复合技术制备组织工程化骨及体内成骨

背景：海藻酸有相对温和的凝胶条件与良好的生物相容性,已广泛应用于生物组织工程。 目的：采用海藻酸钠凝胶复合异种骨的方法,构建骨组织工程载体,观察载体中细胞的生物性能及体内成骨能力。 方法：取2 只2 周龄新西兰兔的骨髓,以1×10-8 mol/L重组人骨形态发生蛋白2诱导骨髓间充质干细胞。取诱导后第2 代骨髓间充质干细胞接种于1%海藻酸钠凝胶中,培养4 d 苏木精-伊红染色观察凝胶中细胞形态。将第2 代骨髓间充质干细胞分为单纯DMEM凝胶组和含1%海藻酸钠的DMEM凝胶组,分别培养7 d 后行骨形态发生蛋白2免疫组织化学染色观察。取24 只裸鼠,随机分为2 组,于两侧股部肌袋中分别植入骨髓间充质干细胞/海藻酸钠凝胶/牛松质骨复合体作为实验组,骨髓间充质干细胞/牛松质骨复合体作为对照组。术后2,4 周后组织学观察复合体成骨情况,图像分析系统分析各组成骨或软骨的面积百分比。 结果与结论：海藻酸钠凝胶中骨髓间充质干细胞形态饱满,细胞悬浮于凝胶中,可见细胞分裂和核分裂相。单纯DMEM凝胶组和含1% 海藻酸钠的DMEM凝胶组免疫组织化学观察,细胞分裂增殖正常,伸出多种形态的突起,胞核大,核仁清晰。单纯DMEM凝胶组和含1%海藻酸钠的DMEM凝胶组的骨形态发生蛋白2 表达阳性率差异无显著性意义(P > 0.05)。扫描电镜观察海藻酸钠凝胶均匀地复合于牛松质骨微孔中,不同平面均有细胞生长。动物实验显示术后2,4 周实验组和对照组的成骨或软骨的面积百分比差异有显著性意义（P < 0.05）。提示以海藻酸钠凝胶/牛松质骨构建骨组织工程载体,合乎组织工程载体的超结构原理,能最大限度地承载细胞,生物性能好,对骨髓间充质干细胞增殖和成骨表型及相关的生物性能无不良影响,在体内成骨效率较高。 关键词：组织工程骨;海藻酸钠凝胶;异种骨;载体;支架材料 doi:10.3969/j.issn.1673-8225.2010.08.043     

A novel canine lymphoma cell line: a translational and comparative model for lymphoma research

A novel canine lymphoma cell line, OSW, was established from the malignant pleural effusion of a dog with peripheral T-cell lymphoma. The immunoprofile as determined by flow cytometry was as follows: positive for CD45, CD49d, CD18, CD11a; weakly positive for CD11b, CD11c, CD11d; and negative for CD45RA, CD1a, CD1c, CD3, TCRβ, TCRγδ, CD4, CD5, CD8a, CD8b, CD90(Thy1), CD21, MHCII, CD14(TUK4), CD34, and MPO. Immunocytochemistry of cytospin preparations was negative for cytoplasmic CD3, CD79a, and MPO, but was positive for CD20. The cell line had an oligoclonal T-cell receptor gamma (TCRγ) gene rearrangement. Array comparative genomic hybridization (aCGH) and single locus probe (SLP) analysis showed that there were copy number increases of loci on dog chromosome 13 (CFA 13), and copy number decreases were evident for regions of CFA 11, 22, 26, 30 and 32, which include several of the more common chromosomal aberrations reported previously in canine lymphoma. The OSW cell line grows rapidly in vitro and is tumorigenic as a xenograft in SCID/NOD mice. OSW represents one of only a few reported canine lymphoma cell lines and is the most thoroughly characterized. This cell line and xenograft represent significant in vitro and in vivo models, respectively, for comparative and translational lymphoma research.     

Transitioning of renal transplant pathology from allograft to xenograft and tissue engineering pathology: Are we prepared?

Currently, the most feasible and widely practiced option for patients with end-stage organ failure is the transplantation of part of or whole organs, either from deceased or living donors. However, organ shortage has posed and is still posing a big challenge in this field. Newer options being explored are xenografts and engineered/bioengineered tissues/organs. Already small steps have been taken in this direction and sooner or later, these will become a norm in this field. However, these developments will pose different challenges for the diagnosis and management of problems as compared with traditional allografts. The approach to pathologic diagnosis of dysfunction in these settings will likely be significantly different. Thus, there is a need to increase awareness and prepare transplant diagnosticians to meet this future challenge in the field of xenotransplantation/ regenerative medicine. This review will focus on the current status of transplant pathology and how it will be changed in the future with the emerging scenario of routine xenotransplantation.     

Diclofenac potentiates the antitumor effect of cisplatin in a xenograft mouse model transplanted with cisplatin-resistant cells without enhancing cisplatin-induced nephrotoxicity

Cisplatin (CDDP) is a well-known anticancer agent, and CDDP–induced nephrotoxicity (CIN) is one of the most serious adverse effects. Previously, we revealed that while celecoxib reduces CIN, diclofenac does not appear to enhance it. Furthermore, we reported that diclofenac additively enhances the cytotoxic effect of CDDP on CDDP-resistant A549 cells (A549/DDP cells) and their spheroids. In addition, celecoxib reduces the cytotoxic effect of CDDP on A549/DDP cells while demonstrating an anticancer effect; however, it enhanced the effect of CDDP cytotoxicity on spheroids. Therefore, we evaluated the effects of diclofenac or celecoxib on CIN and the antitumor effect of CDDP in a xenograft mouse model transplanted with A549/DDP cells. Although CDDP did not decrease tumor size and tumor weight, these parameters were significantly reduced following co-administration with diclofenac when compared with the control group. Conversely, celecoxib marginally suppressed the antitumor effect of CDDP. Moreover, CDDP increased the mRNA levels of kidney injury molecule 1 (Kim-1), a renal disorder marker, in the kidneys of xenograft mice; treatment with celecoxib and diclofenac did not impact Kim-1 mRNA levels increased by CDDP. In conclusion, diclofenac potentiated the antitumor effect of CDDP without enhancing CIN.     

Is induced membrane technique effective in reconstruction of mandibular segmental bone defects? An experimental study

This study aimed to compare the effectiveness of different graft materials using induced membrane technique for reconstruction of mandibular segmental bone defects.New Zealand rabbits were used as the experimental animal. As first-stage surgical procedure, segmental bone defects were created at the lower border of the mandibula in all groups. Polymethylmethacrylate (PMMA) cement was inserted into the defects. After 6 weeks, PMMA cement was removed in all groups. In the Control group, defect areas were left empty. Defects were filled with autogenous graft in the Autograft group, xenograft in the Xenograft group, and a mixture of autogenous graft and xenograft in the Autograft + Xenograft group. Histopathological, stereological, and immunohistochemical analyses were performed.A total of 40 New Zealand rabbits were used. Rabbits were randomly divided into four subgroups as Control, Autograft, Xenograft and Autograft + Xenograft groups (n = 10). When the groups were compared in terms of newly formed bone tissue volumes, significant difference was found between the Control group and Autograft group, Xenograft group and Autograft + Xenograft group (p < 0.001, p < 0.001, p = 0.003). The results of immunohistochemical examination were consistent with this finding.Stereological and immunohistochemical results can be used as a justification to adopt the induced membrane technique on an experimental basis in humans when it comes to the reconstruction of small segmental mandibular defects.     

氯喹对肝癌细胞体内外生长的影响及其与自噬的关系

背景与目的:氯喹是一种广泛应用于疟疾、类风湿性疾病治疗的药物,同时还是一种自噬抑制剂,而且多项研究表明,氯喹能抑制包括肝癌在内的多种肿瘤细胞的生长。本研究在体外细胞实验与荷瘤鼠模型上进一步观察氯喹对肝癌的抑制作用及其与自噬的关系。方法:不同浓度的氯喹(0、25、50 μmol/L)体外作用于肝癌Huh7细胞后,用MTT法检测细胞的增殖情况。将75只裸鼠皮下接种Huh7细胞建立肝癌裸鼠移植瘤模型后,随机均分为3组,于接种后7 d(均已成瘤)分别腹腔注射生理盐水(对照组)、25 mg/kg氯喹(低剂量氯喹组)、50 mg/kg氯喹(高剂量氯喹组),1次/d,连续30 d。期间记录各组肿瘤生长情况,实验结束时,收集移植瘤标本,分别用免疫组化与Western blot法检测移植瘤内自噬相关蛋白(LC3、p62)的表达。结果:MTT检测结果显示,与对照组比较(0 μmol/L),两个浓度氯喹均能明显抑制肝癌Huh7细胞的增殖,并呈明显的时间、浓度效应(均P0.05)。荷瘤鼠模型中,两个剂量氯喹组的肿瘤生长均较对照组明显抑制,且高剂量氯喹组较低剂量氯喹组的肿瘤生长抑制更为明显(均P0.05);免疫组化与Western blot结果显示,两个剂量氯喹组肿瘤组织中LC3、p62的表达水平均较对照组明显升高,且高剂量氯喹组的升高水平明显大于低剂量氯喹组(均P0.05)。结论:氯喹体外与体内均能抑制肝癌细胞的生长,其作用机制可能与其调节自噬相关蛋白的表达抑制肝癌细胞自噬有关。     

受体外周血IgG、MΦ、NK、CD4、CD8及MLR的变化与异种移植物存活的关系

目的探讨受体外周血IgG、MΦ、NK、CD4、CD8及MLR的变化与异种移植物存活的关系。方法选用小鼠移植于大鼠耳后心肌组织模型,按实验所设Ⅰ、Ⅱ、Ⅲ、Ⅳ组在术前12、8、4、0d及10、6、2、0d分别将小鼠脾细胞1×10     

Transplantable zebrafish models of neuroendocrine tumors

Neuroendocrine tumors (NETs) are rare neoplasms whose incidence is increasing. NETs constitute a heterogeneous group of tumors. Their clinical features, functional properties, and clinical course are different on the basis of their site of origin. Due to the heterogeneity of these tumors, a coordinated multidisciplinary approach is required in these patients. However, medical doctor encounters many difficulties when providing care for patients with NETs. This review provides an overview of the state of the art of zebrafish model in the cancer research with a main focus on NETs.     

Localization of Small-cell Lung Cancer Xenografts with Iodine-125-, Indium-111-, and Rhenium-188-Somatostatin Analogs

We examined the potential of radiolabeled somatostatin analogs, ¹²⁵I-Tyr-3-octreotide (¹²⁵I-octreotide), ¹¹¹In-DTPA(diethylenetriaminepentaacetatic acid)- d -Phe-1-octreotide (¹¹¹In-octreotide), and ¹⁸⁸Re-octreotide for targeting small-cell lung cancer (SCLC) in a mouse model. Tyr-3-octreotide was labeled with ¹²⁵I by the chloramine T method, and ¹¹¹In-octreotide was obtained as a kit, while ¹⁸⁸Re was eluted from a ¹⁸⁸W/¹⁸⁸Re generator, and octreotide was directly labeled with ¹⁸⁸Re by reducing disulfide bonds. The ¹²⁵I-, ¹¹¹In-, and ¹⁸⁸Re-octreotides were injected i.v. into athymic mice bearing NCI-H69 tumors, and the biodistributions were determined at 15 min, and 2, 4, 8, and 24 h. Tumor uptakes were 0.5±0.2, 0.3±0.1, 0.3±0.1 %ID/g, and tumor-to-blood ratios were 1.8, 11.9, 1.2 at 8 h for ¹²⁵I-, ¹¹¹In-, and ¹⁸⁸Re-octreotides, respectively. Accumulations of ¹¹¹In-octreotide in normal tissues were lower than those of ¹²⁵I- and ¹⁸⁸Re-octreotides. ¹⁸⁸Re-octreotide can be used to localize SCLC lesions as efficiently as radioiodinated octreotide. However, ¹¹¹In-octreotide was the most suitable agent to obtain high tumor-to-normal tissue contrast for localizing SCLC.     

In vivo antitumor efficacy of 17-DMAG (17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride), a water-soluble geldanamycin derivative

Purpose To describe the preclinical basis for further development of 17-dimethyl aminoethylamino-17-demethoxygeldanamycin hydrochloride (17-DMAG, NSC 707545).Methods In vitro proliferation assays, and in vivo model studies in metastatic pancreatic carcinoma and subcutaneous xenograft melanoma and small-cell lung carcinoma models.Results 17-DMAG emerged from screening studies as a potent geldanamycin analog, with the average concentration inhibiting the growth of the NCI anticancer cell line drug screen by 50% being 0.053 M. Head to head comparison with 17-allylamino-17-demethoxygeldanamycin (17-AAG, NSC 330507) revealed 17-DMAG to possess potent activity against certain cell types, e.g., MDA-MB-231 breast carcinoma and HL60-TB leukemia which were relatively insensitive to 17-AAG. Evidence of oral bioavailability of 17-DMAG in a saline-based formulation prompted more detailed examination of its antitumor efficacy in vivo. 17-DMAG inhibited the growth of the AsPC-1 pancreatic carcinoma xenografts growing as intrahepatic metastases at doses of 6.7–10 mg/kg twice daily for 5 days administered orally under conditions where 17-AAG was without activity. 17-DMAG in an aqueous vehicle at 7.5–15 mg/kg per day for 3 days on days 1–3, 8–10 and 13–17, or 1–5 and 8–12 showed evidence of antitumor activity by the parenteral and oral routes in the MEXF 276 and MEXF 989 melanomas and by the parenteral route in the LXFA 629 and LXFS 650 adenocarcinoma and small-cell carcinoma models. The latter activity was comparable to the historical activity of 17-AAG.Conclusions Taken together, the in vivo activity of 17-DMAG supports the further development of this water-soluble and potentially orally administrable geldanamycin congener.