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51.
The histopathological response and cell culture characteristics of liver cells from the R16 (grc ) strain of rats, which carries an MHC-linked deletion, were examined one week after a single intraperitoneal injection of 200 mg/ kg body weight diethylnitrosamine (DEN) and were compared with the response of liver cells from wild type (grc+) rats. The DEN exposure induced hydropicl vacuolar changes in the parenchymal cells and a limited proliferation of oval cells in the periportal areas of the livers of both grc+ and grc rats. Primary culture of collagenase-digested livers consisted of parenchymal, bile ductular and oval-related cells as determined by cell-specific immunohistochemistry. Subpassaged cells from grc+ rats exhibited oval cell ultrastructural morphology, inducible histochemical staining for gammaglutamyl transpeptidase (GGT), and DEN-associated onset of anchorage-independent growth. Primary cultures of liver cells from R16 rats consistently failed to form cell strains upon subpassage.Abbreviations DEN diethylnitrosamine - grc growth and reproduction complex - GGT gamma-glutamyl transpeptidase - MHC major histocompatibility complex  相似文献   
52.
Summary The adult rat lung cytoplasm contains some factors which markedly stimulate adenylate cyclase activity in plasma membranes (Nijjar, M. S. Biochim. Biophys. Acta 584:43–50, 1979). Adenylate cyclase activator (ACA) was purified from rat lungs by DEAE-cellulose chromatography, preparative isoelectric focusing and by repeated high-performance liquid chromatography on a Sepharogel TSK 2000SW column. The final preparation showed about 200 fold purification in ACA activity over the original lung supernatant, and appeared to be homogeneous on the basis of its migration into a single band on SDS-polyacrylamide gel electrophoresis, and co-elution of ACA activity with protein from a gel exclusion column. ACA is an acidic (pl 4.8 ± 0.1), heat labile, monomeric protein of 40000 ± 2000 dalton molecular weight, and does not resemble calmodulin.  相似文献   
53.
Circulating antibodies against Faenia rectivirgula, Thermoactinomyces candidus, T. vulgaris and Aspergillus fumigatus were studied in the sera of 14 clinically proven farmer's lung patients and 10 normal controls using three immunological methods. These methods were agar gel double diffusion (DD), biotin-avidin-linked immunosorbent assay (BALISA) and dot-immunobinding assay (DIBA). Agar gel diffusion, the least sensitive of the three methods, failed to detect antibodies in some of the patients, while BALISA detected antibodies even in the normal controls. However, the sensitivity of dot-immunobinding assay was in between DD and BALISA while the specificity was comparable to DD to all the antibodies except against A. fumigatus antigens. Dot-immunobinding assay gave faster results than DD and the blots can be stored as record for longer periods of time without fading.  相似文献   
54.
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.  相似文献   
55.
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-Trp7,9, 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.  相似文献   
56.
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  相似文献   
57.
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。  相似文献   
58.
Cell surface heparan sulfate proteoglycan and the neoplastic phenotype   总被引:3,自引:0,他引:3  
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.  相似文献   
59.
Murine squamous carcinoma cells (KLN205) grown in a medium supplemented with the retinoid, 13-cis retinoic acid (RA), had dose-dependent, selective increases in the expression of certain lectin receptors, which correlated with a dramatic decrease in the ability to form pulmonary colonies (P ?.0003) (Couch MJ, Pauli BU, Weinstein RS, Coon JS: JNCI, 78:971 ?977, 1987). These findings suggest a possible relationship between the RA-induced glycoconjugate alterations and the decreased experimental metastatic behavior. We further define the mechanism of RA's action. The finding that RA treatment (5 × 10?6 M, 5 × 10?7 M) did not perturb the cell cycle of KLN205 cells provides further proof that the decreased metastatic behavior is not attributable to any inhibition in the rate of growth or to alterations in the cell cycle. Furthermore, since stable subpopulations with variable lectin binding could not be detected, the mechanism of RA's action does not appear to be due to selection of variant tumor-cell subpopulations. Finally, in a scries of experiments designed to determine the reversibility of the RA treatment, the RA-induced decrease in metastatic behavior reverted back to a more metastatic state in the same time frame (3 days) as the reversion of the RA-induced changes in cell-surface glycoconjugate expression. This reversion provides further evidence for a close relationship between the RA-induced modulation of tumor cell-surface glycoconjugate expression and the decreased metastatic behavior; it suggests that transient, reversible modulation of the tumor cell surface may play a role in determining metastatic behavior.  相似文献   
60.
层粘连蛋白(Laminin,LN)是基膜(basement membrane)中的一种主要大分子糖蛋白。一些研究资料表明肿瘤细胞的浸润转移可能与LN有关。肿瘤细胞与LN的作用可能是通过细胞表面LN受体进行的。本文采用亲和层析法从小鼠Lewis肺癌组织中分离LN受体并对其理化性质进行研究。Lewis肺癌LN受体的表观分子量为70,000,还原后SDS电泳图为一条较宽的条带。氨基酸组成中疏水氨基酸占38%,苏氨酸、絲氨酸、门冬氨酸(包括门冬酰胺)占23.5%,通过硝酸纤维素膜片法用HRP-LN测定受体与LN的结合特性,证明具有配基结合专一性,饱和性及高亲和性(Kd=0.95×10~(-9)mol/L)。  相似文献   
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