DNA flow-cytometric analysis in colorectal cancer: A comparison of metastasizing and non-metastasizing tumours

The most common cause of death in patients with colorectal cancer is metastatic liver disease. In order to identify patients at a high risk of developing hepatic secondaries from colorectal cancers, DNA content was measured in metastasizing colorectal primaries (Group I, n= 32) as well as in their subsequently resected liver secondaries and in sections of non-metastasizing colorectal cancers (Group II, n= 25). A modified interpretation system involving both a DNA index and percentage of cycling cells (those in S and G2 + M phases) was developed. DNA content was measured in paraffin-embedded sections by flow cytometry using internal controls (human peripheral blood mononuclear cells) and non-malignant tissue controls (19 patients with diverticular disease). In Group I there were significantly more tumours with both abnormal ploidy (aneuploid or abnormal tetraploid peak) and > 15% cycling cells compared with Group II (Chi-squared; P= 0.034). The combination of abnormal ploidy and > 15% cycling cells was superior to Dukes’ classification for identifying metastasizing tumours (Logistic Regression; P= 0.047). However, it was not possible to discriminate between the two groups using either DNA ploidy or the percentage of cycling cells alone. The metastasizing colorectal cancers exhibited similar DNA ploidy characteristics and had a similar percentage of cycling cells compared with their liver metastases. These results suggest that tumour DNA ploidy plus the percentage of cycling cells may predict the development of liver metastases and thus survival in patients with colorectal cancer.     

Cloning of Human α-defensin-1 (HNP-1) Gene and Construction of Its Eukaryotic Expression Vector

1 Introduction Defensins are small cationic antimicrobial peptides that function in the host's innate immune system. The human defensin family includes three small peptides from the azurophil granules of polymorphonuclear cells named human neutrophil peptide (HNP)-1, HNP-2, HNP-3,which consist 5%-7% of the protein of human neutrophil. HNP-4 is approximately one hundred times less abundant. They demonstrate antibacterial, antifungal and antiviral properties in vitro. HNPs are important component of nonoxidative mechanism in macrophages, and can direct inactivate the enveloped viruses. Because only special cells express defensins. And it is hard to extract them naturally and the production is few. So researcher expect to obtain defensins highly through heterogenous expression by gene engineering technology. In order to express HNP-1, we cloned the cDNA of HNP-1 from human polymorphonuclear cells in peripheral blood, and constructed its eukaryotic expression vector, which provided a base for the further study on its mechanism of antimicrobial effect.     

白细胞介素-4和γ-干扰素基因联合治疗胶质瘤

目的 探讨逆转录病毒载体介导的白细胞介素(IL)-4和γ-干扰素(IFN)基因联合治疗胶质瘤的作用。方法构建携带IL-4或IFN-γ基因的逆转录病毒载体，将其导入逆转录病毒包装细胞；将携带IL-4和IFN-γ基因的逆转录病毒包装细胞分别或联合注射到脑内荷瘤大鼠的肿瘤组织中，观察其治疗作用。结果成功获得携带治疗基因的逆转录病毒包装细胞PA317IFN-γ和PA317IL-4，所产病毒滴度分别为2x10^6cfu／ml和2．5x10^6cfu／ml。包装细胞瘤内注射能够诱导大鼠产生抗肿瘤免疫反应，杀伤肿瘤细胞，联合应用具有协同治疗作用。结论携带IL-4或IFN-γ基因的逆转录病毒包装细胞瘤内注射是一种有效的胶质瘤基因治疗方法，两者联合应用具有协同治疗作用。     

Brevibacterium sp.DGCDC-82发酵罐中生产胆固醇氧化酶

用Brevibacterium sp.DGCDC-82在7L发酵罐中分批培养.分别对添加剂吐温-80、培养温度、培养基的pH、通风量和搅拌速度在胆固醇氧化酶的生产中的影响进行了研究.结果显示以上条件均对产酶有影响.在不同的发酵阶段改变发酵操作条件,发酵20 h最高酶活可达1203U/L,生产强度可达60 U/(L·h).既有效地提高了胆固醇氧化酶的产量,又防止了发酵过程中的泡沫外溢.     

假单胞菌胆固醇酯酶的生产Ⅰ.菌种筛选和发酵条件的研究

通过平板初筛和摇瓶复筛,从371株菌中筛得一株有工业生产价值的胆固醇酯酶产生菌,并对它进行了发酵条件的研究。用所获得的胆固醇酯酶配制的三酶试剂具有良好的稳定性,适用于临床检测。     

成牙本质细胞中上游刺激因子1对骨桥素表达调控的研究

目的检测成牙本质细胞中上游刺激因子1（upstream stimulatory factor 1，USF1）对骨桥素表达的影响。方法培养成牙本质细胞MDPC-23，稳定转染PCMV-USF1和酸性-USF（A-USF）质粒，提取总RNA，半定量反转录聚合酶链反应检测骨桥素的表达水平，并对结果进行统计学分析。结果筛选出稳定转染USF1和A-USF的抗性克隆，USF1、A-USF转染组和对照组骨桥素相对灰度比值分别为：60．33％±4．51％、229．33％±7．09％、110．00％±15．62％，转染组与对照组差异有统计学意义（P〈0．01）。结论USF1可调控成牙本质细胞骨桥素mRNA转录，该作用被A-USF部分阻断。     

脐带夹对防止脐部感染和出血的临床与实验研究

目的应用国产脐带夹用于农村山区破伤风高发区，并经离体试验验证其可靠性。方法经湖南、江西、广西等省基层接生员临床应用、并与当地同期或前一年未用夹者进行对照；同时经离体脐带用脐带夹、气门芯或纱线结扎阻断血管后进行金黄色葡萄球菌和破伤风毒素通透试验以及测试承受气压程度试验。结果1年临床使用2296例中，无1例发生破伤风和败血症。可靠性试验结果证明，粗纱线结扎最差，气门芯虽优于前者，但不如脐带夹。结论该脐带夹由于夹持力持久有力，细菌、毒素难以通过、安全可靠，因此能降低新生儿“病从脐入”的发病率和死亡率，有利干优生优育的贯彻．这是一项花费少、收效大的简而易行的适宜技术，值得推广。     

TANGO2全身敲除小鼠在生理条件下正常发育和繁殖

目的：利用运输和高尔基体组织蛋白2同系物(transport and Golgi organization protein 2 homolog,TANGO2)敲除小鼠阐明TANGO2在哺乳动物中的生理功能,探究TANGO2是否是导致DiGeorge综合征发生的候选基因。方法：制备TANGO2敲除小鼠模型,通过实时荧光定量PCR检测该小鼠模型的基因敲除效率。观察并记录野生型、杂合和纯合敲除小鼠的表型和生长繁育情况。通过组织解剖和组织学分析,观察野生型和敲除小鼠的心脏和大脑组织的形态结构。结果：TANGO2 mRNA在野生型小鼠的心脏和大脑中表达,而在敲除小鼠相应组织中的表达水平显著降低。TANGO2敲除小鼠发育正常,能够存活和繁殖,没有明显的表型异常。与野生型同窝仔相比,生存率没有显著差异。组织形态分析显示,新生敲除小鼠和6月龄敲除小鼠的心脏和大脑与野生型之间无明显差异。结论：TANGO2敲除小鼠能够正常发育和繁殖,并且缺乏人类中TANGO2相关疾病或DiGeorge综合征的相关表型。     

实时定量RT-PCR的原理及方法

实时定量RT-PCR广泛应用于定量检测mRAN表达水平,为基础研究、分子药物学和生物技术研究提供了一种有力的方法。该法具有易操作、高通量、敏感性高和特异性强的特点,随着新酶、新探针和新仪器的发展而得到快速的发展。本文将对实时定量RT-PCR的定量原理、仪器应用、探针种类的研究进展以及细胞因子mRNA表达水平检测上的应用作一综述。