器官移植的伦理切入点：生命价值☆

背景：随着医学科学技术的快速发展,器官移植已经被人们广泛认同,移植范围也在不断扩大,因此更需要伦理学的支持和辩护。 目的：通过剖析人的生命价值及其意义,让人们的生命价值得到尊重,使器官移植技术得到更多的伦理帮助和支持。 方法：应用计算机检索2001-01/2011-05 CNKI数据库相关文章,检索词为“器官移植,伦理,价值,生命价值”,并限定文章语言种类为中文。共检索到文献164篇,最终纳入符合标准的文献21篇。 结果与结论：随着医学科学技术的快速发展,人们的健康、生命以及生命质量得到进一步的保障。器官移植技术让更多的器官衰竭患者心中升起了生的希望。让更多的生命得到尊重,生命价值得以实现,人类的生命神圣性与生命质量达到完美的统一。器官移植之所以得到世人的认可和青睐,根本的原因在于它体现了人的生命价值的价值。     

Study of the NKT cell subsets with superantigen SEB-activated tolerance

AIM: To study the NKT cell subsets and their differentiation. METHODS: Splenic lymphocytes from C57BL/J mice that had received SEB treatment were collected as effector cells on the 10(th) day. The cells were cultured in medium containing ConA, LPS and IL-2 for 3 days and measured their response to mitogens and cytokine. The inhibitory action of the effector cells was examined. The effector cells were cultured with normal lymphocytes and above mitogens or cytokine for 3 day. The cells proliferation was assessed with MTT method.The NKT cell subsets among these effector cells with the tolerance function were analyzed and their differentiation sources and correlation of functions were detected by flow cytometry. RESULTS: The response of SEB-activated effector cells to ConA, LPS and IL-2 was significantly decreased compared with that of normal lymphocytes. The A values of cell proliferation were decreased from 0.80+/-0.04, 0.60+/-0.03 and 0.55+/-0.07 in control groups to 0.60+/-0.05, 0.30+/-0.05 and 0.27+/-0.04 in effector groups, respectively (P<0.01, n=3).The inhibitory ability of effectors cells against the response of normal lymphocytes to ConA, LPS and IL-2 were clearly observed. They inhibited the response of normal lymphocytes to several mitogens and cytokine. And the A values of cell proliferation were decreased to 0.26+/-0.02, 0.48+/-0.04 and 0.34+/-0.02, respectively (P<0.01, n=3). The CD4(+)NK1.1(+), CD8(+)NK1.1(+), TcRV8(+)NK1.1(+) NKT cell subsets among SEB-activated effector cells with tolerance function were significantly increased and shown that they come from T cell population. And the CD4(-)CD8(-)/NK1.1(+)CD3(+)NKT cells by ConA or SEB-activated were shown coming from NK cell population. CONCLUSION: The effector cells with tolerance function activated by superantigen SEB relate to CD4(+)NK1.1(+), CD8(+)NK1.1(+), TcRVbeta8(+)NK1.1(+) NKT cell subsets. The NKT cell subsets come from T cells. The CD4(-)CD8(-)/NK1.1(+)CD3(+)NKT cells differentiating from NK cells are not involved in the regulation of tolerance.     

Generating functional CD8+ T cell memory response under transient CD4+ T cell deficiency: implications for vaccination of immunocompromised individuals

Studies based on either MHC class II-knockout or CD4+ T cell-depleted murine models have demonstrated a critical role for CD4+ T cells in the generation of CD8+ T cell memory. However, it is difficult to extend these findings to immunocompromised humans where a complete loss of CD4+ T cells is rarely observed. Here, we have developed a model setting, which allows studies on the generation of CD8+ T cell memory responses in a transient CD4+ T cell-deficient setting similar to that seen in immunocompromised patients. Immunisation with an adenoviral vaccine under transient helpless or help-deficient conditions showed varying degrees of impact on the priming of CD8+ T cell responses. Antigen-specific T cells generated under normal CD4+ T cell help and transient help-deficient conditions showed similar effector phenotype and were capable of proliferation upon secondary antigen encounter. Most importantly, in spite of CD4+ T cell deficiency, the long-term CD8+ T cell memory response remained functionally stable and showed comparable cytotoxic effector function as seen in CD8+ T cells generated with normal CD4+ T cell numbers. These findings provide evidence that in spite of partially impaired activation of a primary CD8+ T cell response, a fully functional and stable memory CTL response can be induced under conditions of severe transient CD4+ T cell deficiency.     

纳米羟基磷灰石骨修复复合材料的研究进展

羟基磷灰石（Hydroxyapatite，HA）是一种性能良好的骨修复材料，但是由于脆性而限制了它在承力部位的应用。天然骨本身是纳米羟基磷灰石（Nanohydroxyapatite，n．HA）和胶原的复合材料，从仿生的角度看，n—HA与其它材料复合可以提高生物相容性和力学性能。目前研究的纳米羟基磷灰石复合材料可分为两类：非降解的纳米羟基磷灰石复合材料和可降解的纳米羟基磷灰石复合材料。前者包括n—HA/聚乙烯、n-HA／尼龙以及n—HA／聚丙烯酸。后者主要有n—HA与胶原、明胶、壳聚糖、聚乳酸和聚酸酐等的复合材料。本文详细综述了近年来纳米羟基磷灰石复合材料的制备、力学性能以及生物学性能的研究进展。     

人IL-6 mRNA的实时定量检测法

目的：建立TaqMan-MGB技术实时定量检测人IL-6 mRNA的方法，并用于检测人外周血单个核细胞在牛膝多糖诱导下IL-6 mRNA的表达。方法：（1）抽取人外周静脉血，EDTA抗凝，用淋巴细胞分离液分离外周血单个核细胞，用Trizol裂解液提取总RNA，将总RNA逆转录为cDNA，PCR扩增IL-6后纯化PCR产物，与pMD 18-T载体进行连接，转化宿主菌DH-5α。提取重组质粒DNA，作为实时荧光定量检测的标准品。建立TaqMan-MGB技术实时定量检测IL-6 mRNA的方法。（2）终浓度分别为0、100、200、400、800和1 600 mg/L的牛膝多糖作用于人外周血单个核细胞，定量检测IL-6 mRNA的表达。结果：（1）酶切分析、PCR扩增以及测序结果均证实IL-6 cDNA成功重组到pMD 18-T载体上。（2）TaqMan-MGB技术检测IL-6 mRNA线性范围广；灵敏度高；特异性好；重复性好。（3）牛膝多糖作用于人外周血单个核细胞后IL-6 mRNA表达增高。结论：TaqMan-MGB技术能较为精确地定量IL-6 mRNA。     

Improvement in the contrast of CEST MRI via intermolecular double quantum coherences

The tremendous potential of chemical exchange saturation transfer (CEST) agents as an emerging class of magnetic resonance imaging contrast media has been demonstrated in recent years. In a CEST experiment, a high CEST contrast is always welcome. However, when the exchange rate is low, which may happen in exchangeable solute protons of low concentration, it is usually hard to obtain an excellent CEST efficiency. Recently, we noted that the intermolecular multiple quantum coherence signal is more sensitive to the changes of the magnetization magnitude than a conventional single quantum coherence signal. Consequently, it may be easier when used in obtaining a CEST contrast. In this note, a modified COSY (two-dimensional correlated spectroscopy) revamped with an asymmetric Z-gradient echo detection (CRAZED) sequence combined with an off-resonance saturation pulse followed by a standard spin-echo imaging sequence was designed to obtain a better CEST contrast image based on the intermolecular double quantum coherence method. An analytical expression was derived from a dipolar field theory. Experiments were performed on an agar-glucose phantom, and the results demonstrate the feasibility of our method.     

新的HCC血清标志物GP73在HCC中的表达及临床价值研究

目的研究新的原发性肝细胞癌（HCC）血清标志物高尔基体蛋白73（GP73）在HCC血清中的表达及临床价值。方法选取确诊为HCC者40例为HCC组;肝炎患者及肝硬化患者120例为肝病组;健康体检者120例为健康组。用双抗体夹心ELISA法检测三组血清GP73浓度;同时检测甲胎蛋白（AFP）及d．L．岩藻糖苷酶（AFU）作对比研究。结果HCC组血清中GP73的表达水平为（399．17±264．43）ng／ml,显著高于肝病组的（105．12±67．79）ng／ml和健康组的（66．51±46．2）ng／ml,差异均有统计学意义（P〈0．05）。GP73、AFP、AFU诊断HCC的敏感性分别为89．28％、62．5％和80．7％：特异性分别为87．1％、78．5％和68．7％,GP73敏感性及特异性均高于AFP和AFU。结论GP73是继AFP、AFU之后另一个新的优秀的诊断HCC血清标志物,具有重要临床价值。     

GDF5基因rs224331多态性与汉族青少年体格发育指标关联分析

目的探讨中国汉族青少年GDF5基因rs224331位点多态性与身高、体重和BMI的相关性。方法采集江苏省某技校1790名17～22岁青少年的身高、体重指标并计算BMI。采用Taqman探针real-timePCR方法检测GDF5基因rs224331位点的单核苷酸多态性,并分析该基因位点与男女生身高、体重和BMI的相关性。结果 97.9%（1754/1790名）基因分型成功,男生859名,女生895名。rs224331位点频率最高的基因型为AA（51.7%）,其次为AC（39.6%）,CC最少（8.7%）。rs224331的基因型分布与男生、女生的身高无显著关联（P分别为0.728和0.723）;rs224331不同基因型间的男生体重和BMI差异均有统计学意义（P均〈0.01）,男生AC基因型体重和BMI均显著高于AA基因型（P=0.002）,女生中未发现类似的相关性（P分别为0.713和0.921）。结论 GDF5基因rs224331位点多态性在本研究的汉族人群中与身高无明显关联,提示该多态性位点可能存在种族特异性。rs224331位点多态性与男生体重和BMI存在相关性。     

PHA、ConA及CD3ε单克隆抗体对小鼠淋巴细胞迁移及分泌趋化因子的影响

目的探讨不同浓度的PHA、ConA及CD3ε单克隆抗体对Balb/c小鼠淋巴细胞迁移及分泌趋化因子的影响,初步了解这3种刺激剂与小鼠淋巴细胞迁移功能之间的关系。方法通过研磨法分离Balb/c小鼠脾脏淋巴细胞,用不同浓度的PHA、ConA及CD3ε单克隆抗体分别刺激培养淋巴细胞,收集细胞上清,用Traswell法测定细胞上清对淋巴细胞迁移率的影响;ELISA法检测细胞上清中趋化因子XCL1、CCL4、CCL5、CCL3、IL-16、IL-8及CCL20的水平。结果 PHA组各个浓度刺激下淋巴细胞的迁移率和对照组无明显差异;ConA组的刺激浓度为20μg/ml时,其对应的淋巴细胞迁移率明显高于对照组;CD3ε单抗组,其浓度分别为2.5、10μg/ml时,对应的淋巴细胞迁移率明显高于对照组。在各个刺激组中,ELISA测得的多种趋化因子水平在总体上存在明显差异。结论 ConA及CD3ε单克隆抗体分别刺激小鼠淋巴细胞后,其分泌趋化因子的功能发生了明显的改变,这些趋化因子影响着小鼠淋巴细胞的迁移功能。趋化因子XCL1、CCL4、CCL5、CCL3的水平明显高于对照,说明这几个因子在淋巴细胞迁移中起到重要的作用。根据实验结果初步推荐CD3ε单抗可以作为小鼠淋巴细胞迁移试验中的首选阳性对照,次选为ConA。