SC9-4和棕榈油的比较分析研究

SC_9-4是以植物油为原料研制成功的一种高速冷轧工艺润滑油。经武钢高速冷轧机轧制性能鉴定,它的高速轧制性能优于棕榈油。我们使用高效液相色谱比较分析鉴定了SC_9-4和棕榈油的甘油三酯组成。分析结果:SC_9-4:的主要甘油三酯是POP(42.8％)和PPP(14.6％),而棕榈油的主要甘油三酯是POP(31.3％)、POO(20.1％)、PLP(12.2％)和PLO(11.6％)。我们初步探讨甘油三酯组成与轧制性能关系认为,SC_9-4的高速轧制性能优于棕榈油,可能是和SC_9-4含PPP、PPS和PSS的含量(18.8％)高于棕榈油(9.9％)有关。     

Serum copper,zinc levels,and copper

Serum copper and zinc levels were determined in 20 healthy women and in 100 women with gynecological tumors. Malignant and benign tumor cases were separated according to their postoperative, histopathological examinations. The stages of malignant and benign tumors were also established histologically. Seventy benign and 30 malignant genital tumors (carcinoma of cervix in situ, cervix, ovary endometrium, and vulva) of the patients were differentiated histopathologically. The serum Cu/Zn ratios of patients were increased significantly from the control group (0.32±0.35) to the benign group (1.22±0.63) and from the benign group to the malignant group (2.24±1.03). Nine of 30 malignant cases were determined as false negative (30%) and 15 of 70 benign cases were determined as false positive (14.2%) according to the serum Cu/Zn ratios of patients. Serum copper levels of 30 malignant and 10 benign tumor cases showed linear correlation with serum ceruloplasmin values.     

Structural and functional domains of cellobiohydrolase I from trichoderma reesei

Limited proteolysis (papain) of the cellobiohydrolase I (CBH I, 65 kDa) from Trichoderma reesei led to the seperation of two functional domains: a core protein (55 kDa) containing the active site, and a C-terminal glycopeptide (10 kDa) implicated in binding to the insoluble matrix (cellulose). The quaternary structures of the intact CBH I and its core in solution are now compared by small angle X-ray scattering (SAXS) measurements. The molecular parameters derived for the core (Rg=2.09 nm, D_max=6.5 nm) and for the intact enzyme (Rg=4.27 nm, D_max=18 nm) indicate very different shapes. The resulting models show a tadpole-like structure for the intact enzyme where the isotropic part coincides with the core protein and the flexible tail part should be identified with the C-terminal glycopeptide. Thus in this enzyme, functional differentiation is reflected in structural peculiarities.Abbreviations SAXS small angle X-ray scattering - SDS-PAGE SDS-polyacrylamide gel electrophoresis - IEF-PAG polyacrylamide gel isoelectric focusing; cellobiohydrolase (CBH, 1,4--glucan cellobio hydrolase (E.C.3.2.1.91)) - D_max maximum diameter - Rg radius of gyration     

Substance P analogues function as bombesin receptor antagonists and inhibit small cell lung cancer clonal growth

Human small cell lung cancer (SCLC) produces and secretes BN/GRP (bombesin/gastrin releasing peptide). Because BN stimulates the growth of SCLC cells and these cells have receptors for BN-like peptides, it is important to define agents which disrupt this self-promoting autocrine growth cycle. Here, substance P analogues were evaluated as BN receptor antagonists using SCLC cell lines. (D-Arg¹, D-Pro², D-Trp^7,9, Leu¹¹) substance P [(APTTL)SP] was one of the more potent analogues tested in inhibiting BN-like peptide receptor binding with an IC₅₀ value of 1 μM. Micromolar concentrations of (APTTL)SP antagonized BN receptor mediated elevation of cytosolic Ca²⁺ levels and decreased the colony formation in soft agarose. These data suggest that SP analogues function as SCLC BN receptor antagonists and may be useful in disrupting the autocrine growth function of BN-like peptides.     

Structural similarities among the high molecular weight protein fractions of oilseeds

Data on the physico-chemical properties of proteins from soybean, groundnut, sesame seed, sunflower seed, safflower seed, mustard seed, rapeseed and cotton seed are fairly extensive. An examination of the available data on high molecular weight proteins suggests that there are similarities in many of their properties. In this report the similarity in amino acid composition, size and shape, molecular weight, secondary structure, subunit composition, association-dissociation at high and low pH, stability towards denaturants, hydrolysis by enzymes and quaternary structure of the high molecular weight proteins is discussed. Based on these similarities a model has been proposed for the associationdissociation, denaturation and reassociation behaviour of the high molecular weight proteins of oilseeds.     

区别人小细胞肺癌和非小细胞肺癌的LSC系列单克隆抗体(简报)

人小细胞肺癌的发病率虽不及非小细胞肺癌,但其五年生存率却相对低得多,这两种细胞类型不仅在病理类型上表现不同,在许多其它性质上也表现不同。小细胞肺癌是一种异质性疾病,它由几种形态不同的瘤细胞组成,包括非小细胞肺癌在内;它易早期转移,能在肝、脑和骨髓中繁殖,具有L-Dopa胱羧酶,神经原特异的烯醇化酶(enolase),能合成神经递质和多肽激素蛙皮肽等特性。目前已有关于小细胞肺癌的单克隆抗体的报道,我们采用美国N I H建立的小细胞肺癌细胞株SH-77作免疫原,目前尚未见有关抗该细胞株的单克隆抗体的报道,现将我们制备的三个单抗体及其初步特异性鉴定结果简报如下     

钙调素抑制剂——三氟拉嗪对肿瘤细胞增殖和微管组装的影响

本文用钙调素抑制剂——三氟拉嗪处理人胃癌MGC-803细胞,用免疫荧光细胞化学方法,放射免疫法和速流荧光分析等方法研究了钙调素对细胞增殖,环核苷酸代谢及微管组装,有丝分裂等细胞功能的调节作用。实验结果表明,TFP明显地抑制了人胃癌细胞的增殖,这种抑制增殖的作用,具有剂量和时间依赖关系,细胞群体中G_1期细胞增多,S期细胞下降,DNA合成明显地受到抑制。TFP处理的胃癌细胞仅在短时间内(5'-30')cAMP含量升高,cGMP浓度降低,cAMP/ ??cGMP比值比对照组高4.4倍,但此后环核苷酸含量又很快恢复到对照组水平。本实验还观察到TFP处理后的MGC-803细胞胞质铺展,细胞形态的改变与胞质微管的分布有密切联系,实验结果表明TFP加强了人胃癌细胞MTOC对微管的组装能力,使微管分布得到恢复,微管纤维呈放射状延伸到细胞边缘,充满胞浆,使细胞呈现出展平的多边形,趋向于正常上皮细胞形态的变化,本实验结果表明TFP抑制癌细胞增殖及使微管组装加强可能是通过对CaM活性的抑制作用。此结果有助于说明转化细胞内钙调素的变化,可能是与转化细胞增殖失控和胞质微管消退有关。     

Cell surface heparan sulfate proteoglycan and the neoplastic phenotype

Cell surface proteoglycans are strategically positioned to regulate interactions between cells and their surrounding environment. Such interactions play key roles in several biological processes, such as cell recognition, adhesion, migration, and growth. These biological functions are in turn necessary for the maintenance of differentiated phenotype and for normal and neoplastic development. There is ample evidence that a special type of proteoglycan bearing heparan sulfate side chains is localized at the cell surface in a variety of epithelial and mesenchymal cells. This molecule exhibits selective patterns of reactivity with various constituents of the extracellular matrix and plasma membrane, and can act as growth modulator or as a receptor. Certainly, during cell division, membrane constituents undergo profound rearrangement, and proteoglycans may be intimately involved in such processes. The present work will focus on recent advances in our understanding of these complex macromolecules and will attempt to elucidate the biosynthesis, the structural diversity, the modes of cell surface association, and the turnover of heparan sulfate proteoglycans in various cell systems. It will then review the multiple proposed roles of this molecule, with particular emphasis on the binding properties and the interactions with various intracellular and extracellular elements. Finally, it will focus on the alterations associated with the neoplastic phenotype and will discuss the possible consequences that heparan sulfate may have on the growth of normal and transformed cells.     

Polystyrene substratum for bulk culture of anchorage dependent cells

Twisted ribbons made of polystyrene were used as a packing material for the cultivation of anchorage dependent cells. Normal human fibroblast cells grown on this support in a laboratory scale reactor reached densities of about 5–7×10⁵ cells/ml. The cells adhered strongly to the carrier and no cell detachment was observed upon transfer to serum free medium. The properties of this packing material and its potential use are discussed.     

大鼠应激性胃粘膜损害与eAMPCa~2及能量代谢变化的关系

本文采用放射免疫测定法、原子吸收光谱分析法和生化酶分析法,测定了大鼠在经受束缚加浸水急性应激四小时内,胃组织cAMP Ca~(2+)及在ATP、ADP、AMP和能量代谢的短期动态变化,同时观察了胃粘膜的损害程度。结果发现胃粘膜损害面积密度随着应激时间延长而逐渐增加;胃组织cAMP和Ca~(2+)则进行性降低;两者呈密切负相关;胃组织能量代谢却略有增强。若预先给以CaCl_2,再予应激,则有减轻应激性胃粘膜损害的作用。