骨髓源间充质干细胞在异基因小鼠免疫器官内的分布及其免疫功能调节作用

目的：探讨骨髓源间充质干细胞(Bone marrow mesenchymal stem cells，BMSC)在异基因小鼠免疫器官内的分布及其免疫调节作用。方法：以CM-Dil荧光染料示踪BMSC的体内分布情况，并辅以PCR检测Y染色体的方法进一步鉴定；体外实验采用MTT法、ELISA和FACS等方法检测BMSC的免疫调节作用。结果：BMSC可进入并较长期(30天)存在于异基因小鼠免疫器官内；在体外，BALB／C小鼠的BMSC对由ConA诱导的BALB／C和C57BL／6(B6)和BXSB小鼠的T细胞增殖均有抑制作用；而对前两种小鼠由12S诱导的B细胞增殖和分泌k方面表现为促进作用，对BXSB小鼠由IPS诱导的B细胞增殖和k分泌有抑制作用。BALB／C小鼠的BMSC对BALB／C和B6小鼠由ConA诱导的IL-4生成细胞的数量无明显影响，却可降低由ConA诱导的两种品系小鼠的IFN-γ生成细胞的数量；但对于BXSB小鼠却不同，BALB／C的BMSC可降低由ConA诱导的BXSB小鼠的IL-4生成细胞的数量，而提高由ConA诱导的IFN-γ生成细胞的数量。结论：异基因BMSC不但可进入受体的免疫器官，且可较长期(30天)存在；另外，BMSC对同基因正常、异基因正常和异基因自身免疫病的个体均有一定程度的免疫调节作用。     

一个新的人B细胞活化抗原—5C5

用活化人B细胞株3D5细胞免疫小鼠和作为筛选的靶细胞,我们建立了产生单克隆抗体5C5的杂交瘤细胞株。此单抗识别的抗原5C5在25μg/ml anti-μ刺激的B细胞,于第10小时开始表达,亦即于G_1期开始表达。5C5细胞百分率随培养时间而增多。在PWM诱导下.外周血单一核细胞中5C5~ 细胞随培养时间而增加,至第3～4天达最高峰,然后减少,至第7天降至本底水平。5C5~ 细胞在不能为BCDF诱导分化至免疫球蛋白分泌细胞(ISC)的B细胞株3D5,Raji和Daudi阳性,但在能为BCDF诱导分化至ISC的CESS和SKW6细胞却不表达。这均表明5C5抗原表达于B细胞活化的早期和中期,但在B细胞终末分化阶段消失。在休止期B细胞、休止期T细胞、PHA激活的T细胞、单核细胞和中性粒细胞,以及在所检测的T细胞株和髓细胞株,5C5抗原均为阴性。~(125)I标记后用单抗5C5免疫沉淀提取的抗原,在还原与非还原条件下电泳,均只有分子量为52000的一条带,表明5C5是一个单链细胞表面蛋白。鉴于5C5抗原的分子量与文献中已报道的B细胞活化抗原分子量不同,以及5C5在细胞株表达的特点,它可能是一个新的人B细胞活化抗原。     

Mitochondrial DNA polymorphisms in Yunnan nationalities in China

Nucleotide sequences of the D-loop region of human mitochondrial DNA from four Yunnan nationalities, Dai, Wa, Lahu, and Tibetan, were analyzed. Based on a comparison of 563-bp sequences in 99 people, 66 different sequence types were observed. Of these, 64 were unique to their respective populations, whereas only 2 types were shared between the Lahu and Wa nationalities. The D-loop sequence variation and phylogenetic analysis suggested that the 99 mtDNA lineages were classified into eight clusters in the phylogenetic tree. All lineages that had a 9-bp deletion in the COII/tRNA^Lys intergenic region appeared in one cluster in the D-loop tree, suggesting a single event of the deletion in the Yunnan nationalities studied. Genetic distances, based on net nucleotide diversities between populations including Han Chinese and mainland Japanese, revealed that the Dai, Wa, Lahu, and Han Chinese are closely related to each other, while Tibetan and mainland Japanese formed a single cluster. The bootstrap probabil-ity of separation between the Dai-Wa-Lahu-Chinese clade and the Tibetan-Japanese clade was 99%, indicating that there are at least two different origins among minority groups in Yunnan province. Although the genetic distance between Tibetan and Japanese within the clade is rather long, the results may shed light on the origins of mainland Japanese. Received: December 22, 2000 / Accepted: January 18, 2001     

PLPP2: Potential therapeutic target of breast cancer in PLPP family

PLPPs (Phospholipid phosphatases) are widely expressed in different human tissues, regulate cell signal transduction, and are overexpressed in cancers such as gliomas, pancreatic adenocarcinoma, lung adenocarcinoma, and so on. As a member of the PLPP family, PLPP2 (phospholipid phosphatase 2) plays a vital role in the occurrence and development of breast cancer, but its mechanism is still unclear. Our research found that PLPP2 was overexpressed in breast cancer, and the higher expression level of PLPP2 showed a worse prognosis for breast cancer patients. Further analysis showed that overexpression of PLPP2 affected the expression of CDC34 (cell-division cycle 34), LSM7 (Like-Smith 7), and SGTA (small glutamine-rich tetratricopeptide repeat-containing protein alpha) through EMT (epigenetic-mesenchymal transition) related pathways to promote the occurrence and development of breast cancer. In vitro, silencing PLPP2 significantly reduced the proliferation, invasion, and migration abilities of human breast cancer cells MDA-MB-231. ER+ is a common subtype of breast cancer. Furthermore, we found that the overexpression of PLPP2 was significantly related to the poor prognosis of ER+ breast cancer. These results indicate that PLPP2 has value as a potential therapeutic target for breast cancer, especially for ER+ breast cancer.     

HIV-1高暴露持续血清阴性者对Nef、Gag肽段库的特异性CTL应答的研究

目的 研究中国HIV-1高暴露持续血清阴性（highly exposed persistently seronegative,HEPS）者的Nef、Gag特异性细胞毒性T淋巴细胞（cytotoxic T lymphocyte,CTL）应答特点,探讨HIV-1特异性CTL应答在这类特殊人群中抵抗感染的作用机制.方法 选取10例HIV-1高暴露持续血清阴性者,11例经性接触感染且从未接受抗病毒治疗的HIV/AIDS患者及4例未经暴露的健康志愿者.以覆盖HIV-1 gag全长和部分nef的14个肽段库为刺激原,应用IFN-γ ELISPOT法测定3组人群的特异性CTL应答,并对3组的应答强度、宽度以及对肽段库识别比例进行比较.结果 50%（5/10）的HEPS,100%（11/11）的HIV/AIDS患者均存在Nef及Gag特异性CTL应答,而4例健康对照均为阴性.存在应答的HEPS者对14个肽段库的平均应答强度和宽度分别是HIV/AIDS患者的4.3%和37.7%.在HEPS者中主要识别的肽段库均为HIV/AIDS患者中识别比例相对较低的肽段库.结论 与HIV/AIDS患者相比,HEPS者中的HIV-1特异性CTL应答存在着不同的特点和规律,可能在保护机体免于HIV-1感染中发挥着重要作用.     

tPA信号肽和鼠疫杆菌保护性抗原V融合基因的构建及免疫效果鉴定

获得含有鼠疫杆菌V抗原编码基因以及tPA信号肽编码序列的重组质粒,并测定其诱导特异性免疫应答的能力。采用PCR扩增鼠疫菌杆菌V基因构建到pVAX1质粒中产生pVAX1/V重组质粒,PCR扩增tPA信号肽编码序列片段并将其插入到pVAX1/V中V基因的上游,构建tPA-pVAX1/V重组质粒;转染COS-7细胞,免疫细胞化学方法鉴定V蛋白的表达;二重组质粒分别加mGM-CSF质粒免疫BALB/c小鼠,观察免疫应答反应;以400个LD50强毒鼠疫杆菌皮下攻击免疫小鼠观察保护效率。结果显示,tPA-pVAX1/V在COS-7细胞中表达了V蛋白;免疫小鼠血清产生了特异性抗体和细胞免疫应答;攻毒保护率达80%。成功构建了分泌型V蛋白的真核表达质粒载体,具有诱导特异性细胞免疫和体液免疫应答的能力,对强毒鼠疫杆菌攻毒有一定的保护效力,为鼠疫杆菌新型疫苗研制奠定了基础。     

An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.     

Immunohistochemical detection of macrophage-derived foam cells and macrophage colony-stimulating factor in pulmonary atherogenesis of cholesterol-fed rabbits

In order to investigate the role of monocyte/macrophages and their relationship to the expression of macrophage colony-stimulating factor (MCSF) in pulmonary atherosclerosis, lungs were excised from rabbits that had been fed for 60 and 90 days on a diet containing 0.5% cholesterol. In the lungs, fatty streaks and elevated foam cell lesions predominated in the large or medium-sized elastic pulmonary arteries, while massive accumulation of foam cells in the intima of muscular arteries produced marked luminal narrowing and nearly complete occlusion. In these lesions, most of the foam cells were reactive with RbM2, a monoclonal antibody (mAb) against rabbit macrophages, while smooth muscle cell-derived foam cells were detected by mAb against smooth muscle actin in the deeper area of elevated foam cell lesions of elastic arteries. Ultrastructural observation confirmed the presence of monocytes in the intima, their differentiation into macrophages, and their transformation into foam cells in the atherosclerotic lesions. lmmunohistochemical expression of MCSF was demonstrated in the endothelial cells, smooth muscle cells and foam cells. A minor macrophagederived foam cell population was demonstrated to possess a prolif-erative capacity. These data suggest that MCSF is involved in the differentiation of monocytes into macrophages, their transformation into foam cells, and their proliferation during pulmonary atherogenesis.     

北京市13家中医综合医院住院医疗服务评价研究

目的建立中医综合医院住院医疗服务评价指标体系,对之进行评价,以明确优势与短板并针对性改进。方法通过文献分析法确定评价指标体系,运用层次分析法对指标权重进行赋值,利用改良TOPSIS法对北京市13家中医综合医院进行排名。结果综合排名前3的分别是E、B、D 三家中医综合医院。服务能力最强的为M医院,服务效率、医疗安全和数据质量最好的均为D医院,运营效益最优的为F医院,中医特色最强的为E医院。结论建立的指标体系能够对中医综合医院住院医疗服务进行客观评价,有利于医院持续改进,从而全面提高服务能力。     

医院开展舞弊审计的难点及对策探讨*

文章通过剖析医院舞弊产生的根源,对医院舞弊审计的特性和难点展开探讨,尝试构建医院舞弊审计的理论框架,并据此从提升审计人员胜任力、发挥内部控制抵御舞弊风险的作用、通过舞弊迹象找出舞弊表现、加强与被审计对象的审计心理博弈、完善和改进舞弊审计的程序与方法、营造防范舞弊的文化氛围等6个方面提出医院实施舞弊审计的对策,以期为公立医院开展舞弊审计提供参考。