犬表皮肿瘤病理诊断及分析

摘要:目的 对 39 例犬表皮肿瘤病例的背景信息、病理学诊断结果进行分析,探讨犬表皮肿瘤发生规律和病理学特点。 方法 收集 39 例患犬的表皮肿瘤,制成切片后进行 HE 染色,利用光学显微镜进行病理学观察并作出诊断,根据诊断结果,对病例的肿瘤类型、发病年龄、性别、发病部位等进行统计分析。 结果 结果显示,犬最常发的表皮肿瘤为鳞状细胞癌,占全部表皮肿瘤病例的 46% ,多为中分化程度的鳞状细胞癌。 其次为占比 39%的乳头状瘤,以 外生性乳头状瘤为主。 基底样鳞状细胞癌较少发生。 乳头状瘤多发于 0 ~ 3 岁幼龄犬,鳞状细胞癌以及基底样鳞状细胞癌多发于 7 岁以上的老龄犬。 雄性的发病率略高于雌性。 表皮肿瘤的发病部位主要位于头面部。 结论 本文总结了犬表皮肿瘤的流行特点及组织病理学特征,为今后该类肿瘤的诊断和鉴别诊断提供参考。     

表皮生长因子受体与胃肠道肿瘤

介绍表皮生长因子受体（EGFR）的生物学特征及其与细胞转化、胃肠道肿瘤的相互关系，以及胃肠道肿瘤治疗新途径。     

Hedgehog signalling in prostate regeneration, neoplasia and metastasis

Metastatic cancers adopt certain properties of normal cells in developing or regenerating organs, such as the ability to proliferate and alter tissue organization. We find here that activity of the Hedgehog (Hh) signalling pathway, which has essential roles in developmental patterning, is required for regeneration of prostate epithelium, and that continuous pathway activation transforms prostate progenitor cells and renders them tumorigenic. Elevated pathway activity furthermore distinguishes metastatic from localized prostate cancer, and pathway manipulation can modulate invasiveness and metastasis. Pathway activity is triggered in response to endogenous expression of Hh ligands, and is dependent upon the expression of Smoothened, an essential Hh response component that is not expressed in benign prostate epithelial cells. Monitoring and manipulating Hh pathway activity may thus offer significant improvements in diagnosis and treatment of prostate cancers with metastatic potential.     

Interaction of peptide antigens and class II major histocompatibility complex antigens

T lymphocytes require a foreign antigen to be presented on a cell surface in association with a self-transplantation antigen before they can recognize it effectively. This phenomenon is known as major histocompatibility complex (MHC) restriction. It is not clear how an incalculably large number of foreign proteins form unique complexes with a very limited number of MHC molecules. We studied the recognition properties of T cells specific for a peptide derived from bacteriophage lambda cI protein. Analogues of this peptide, as well as peptides derived from other unrelated antigens which can be presented in the context of the same MHC molecule, can competitively inhibit activation of these T cells by the cI peptide. Furthermore, these unrelated antigens can stimulate cI-specific T cells if certain specific amino-acid residues are replaced. Here we suggest a model in which all antigens give rise to peptides that can bind to the same site on the MHC molecule. T-cell recognition of this site (which is presumed to be polymorphic) with or without antigen bound can explain self-selection in the thymus and MHC restriction.     

吉林省接骨木属叶表皮微形态研究

接骨木属植物具有较高的食用、药用及经济价值,分布较分散.为探知接骨木属分种之间的亲缘关系,利用扫描电镜对吉林省接骨木属叶表皮微形态进行定性描述及主成分分析和聚类分析.结果表明:1)叶表皮具毛或无毛;上表皮细胞壁分为凸起和凹陷两种类型;气孔器有椭圆形和狭长椭圆形两种类型;叶表皮气孔大小、密度和表皮毛长短及密度等均存在差异.2)主成分分析选出4个主成分,方差累计贡献率达到81.665%.3)聚类分析结果表明:吉林省接骨木属植物分为两大类群.第Ⅰ类为有毛类,包括毛接骨木和宽叶接骨木,表现为叶表皮两面均具毛;气孔器为狭长椭圆形;气孔周边条纹小于1μm;上表皮细胞壁凸起,细胞呈不规则形,垂周壁式样为波状.第Ⅱ类为无毛类,包括接骨木、钩齿接骨木、东北接骨木和朝鲜接骨木,表现为叶表皮两面均无毛;气孔周边条纹大于1μm;上表皮细胞为多边形,垂周壁式样为平直-弓形.利用叶表皮微形态特征,编制吉林省接骨木属分种叶表皮分类检索表,说明叶表皮微形态特征可以作为吉林省接骨木属种下分类的重要特征.     

镁离子对鼠角质细胞生长和分化的影响

利用无血清培养基培养角质细胞，研究Mg^2 对鼠角质细胞生长和分化的影响。实验结果表明，培养基中Mg^2 浓度为5．0mmol／L时，细胞贴壁率、克隆形成率明显增加，细胞分化比例和老化比例均达到最低。当Mg^2 浓度达到10．0mmol／L时，细胞增殖水平没有显著提高，角质细胞分化比例和老化比例却有一定程度的提高。培养基中加入一定浓度的Mg^2 能够刺激角质细胞的增殖，抑制角质细胞的分化，并且延缓细胞的老化。