5-羟色胺转运体抑制剂对肺动脉高压肉鸡肺小动脉中膜5-HT量和平滑肌细胞增殖的影响

【目的】探讨肉鸡肺小动脉中膜5-羟色胺（5-HT）含量与肺小动脉平滑肌细胞增殖的关系,明确5-羟色胺转运体（5-HTT）是否参与了肉鸡肺动脉高压的发生。【方法】20日龄科宝肉鸡分成非诱病组（静脉注射生理盐水,包括空白对照组、氟西汀、西酞普兰组,30只/组）和诱病组（静脉注射纤维素微粒,包括药物空白对照组、氟西汀组、西酞普兰组,50只/组）。自21d起,记录肺动脉高压综合征（PHS）发病率,并分别于21、28、35、42d从各组随机抽样,测定右心室/全心室重量比（RV/TV）,采用免疫组织化学技术、增殖细胞核抗原（PCNA）染色和核仁组织区嗜银蛋白（AgNOR）染色方法检测肺小动脉中膜5-HT量及肺小动脉平滑肌细胞增殖情况。【结果】诱病组PHS发病率、RV/TV明显高于非诱病组（P＜0.05）,肺小动脉中膜5-HT量增加,平滑肌细胞上嗜银颗粒增多,PCNA阳性细胞增多,而两种5-HTT抑制剂（氟西汀和西酞普兰）能明显减少肉鸡PHS发病率和肺小动脉中膜5-HT量,抑制平滑肌细胞增殖,但两种药物之间无明显差异。【结论】在肉鸡肺动脉高压发生过程中,由5-HTT介导的肺小动脉平滑肌细胞内5-HT增多,引起肺小动脉平滑肌细胞过度增殖,导致肉鸡PHS发生,5-HTT可能是防治肉鸡PHS的有意义靶分子。     

Activation of developmentally mutated human globin genes by cell fusion

Human fetal globin genes are not expressed in hybrid cells produced by the fusion of normal human lymphocytes with mouse erythroleukemia cells. In contrast, when lymphocytes from persons with globin gene developmental mutations (hereditary persistence of fetal hemoglobin) are used for these fusions, fetal globin is expressed in the hybrid cells. Thus, mutations of developmental origin can be reconstituted in vitro by fusing mutant lymphoid cells with differentiated cell lines of the proper lineage. This system can readily be used for analyses, such as globin gene methylation, that normally require large numbers of pure nucleated erythroid cells, which are difficult to obtain.     

Targeting of nonexpressed genes in embryonic stem cells via homologous recombination

Gene targeting via homologous recombination-mediated disruption in murine embryonic stem (ES) cells has been described for a number of different genes expressed in these cells; it has not been reported for any nonexpressed genes. Pluripotent stem cell lines were isolated with homologously recombined insertions at three different loci: c-fos, which is expressed at a low level in ES cells, and two genes, adipsin and adipocyte P2 (aP2), which are transcribed specifically in adipose cells and are not expressed at detectable levels in ES cells. The frequencies at which homologous recombination events occurred did not correlate with levels of expression of the targeted genes, but did occur at rates comparable to those previously reported for genes that are actively expressed in ES cells. Injection of successfully targeted cells into mouse blastocysts resulted in the formation of chimeric mice. These studies demonstrate the feasibility of altering genes in ES cells that are expressed in a tissue-specific manner in the mouse, in order to study their function at later developmental stages.     

Specific expression of a tyrosine kinase gene, blk, in B lymphoid cells

Several pathways of transmembrane signaling in lymphocytes involve protein-tyrosine phosphorylation. With the exception of p56lck, a tyrosine kinase specific to T lymphoid cells that associates with the T cell transmembrane proteins CD4 and CD8, the kinases that function in these pathways are unknown. A murine lymphocyte complementary DNA that represents a new member of the src family has now been isolated and characterized. This complementary DNA, termed blk (for B lymphoid kinase), specifies a polypeptide of 55 kilodaltons that is related to, but distinct from, previously identified retroviral or cellular tyrosine kinases. The protein encoded by blk exhibits tyrosine kinase activity when expressed in bacterial cells. In the mouse and among cell lines, blk is specifically expressed in the B cell lineage. The tyrosine kinase encoded by blk may function in a signal transduction pathway that is restricted to B lymphoid cells.     

甘肃省河西地区马类动物气喘病形态变化及其病理发生

这是一篇关于甘肃省河西地区12例动物气喘病病理研究报告。气喘病畜包括马5例、骡5例和驴2例,年龄为5—18岁。病肺高度膨大,其切面细支气管明显。肺的主要组织变化有慢性支气管炎和血管周炎、间质性肺炎、内含析光性无机粉尘的巨噬细胞灶和结节,有些病例的肺泡及其间隔中,还有大量巨噬细胞和巨细胞。从这些病例的肺中分到了普通高温放线菌、干草小多孢菌、热吸水链霉菌和高大毛霉菌。在肺尘细胞中看到了超微结构变化,如线粒体空泡化和内质网脱粒。同时这些细胞的无机元素(铝、硅等)含量增加。故认为本病是一种由外界吸入的无机尘与有机尘所致的混合性尘肺。     

Biochemical and cytological evidence for triple hybrid cell line formed from fusion of three different cells

Hybrids between two parental lines of somatic cells have been observed in various genomic multiplicities by ourselves and others. Possible explanations for the higher multiplicities include the fusion of cells in a 1:1 ratio with one genomic set undergoing an asynchronous replication either before or after fusion or the fusion of two or more cells. We now provide evidence for multiple genomic hybrids arising from the fusion of more than two cells in a mixture of three different cell lines. This proof is based on unique chromosomal and biochemical markers characteristic of the three parental cell lines. The distinctive phenotypes of all three lines are expressed in a clonally derived hybrid. Thus, we conclude that long-term, proliferating somatic cell hybrids can arise from the fusion of three or more cells.     

Regulation of cutaneous malignancy by gammadelta T cells

The localization of gammadelta T cells within epithelia suggests that these cells may contribute to the down-regulation of epithelial malignancies. We report that mice lacking gammadelta cells are highly susceptible to multiple regimens of cutaneous carcinogenesis. After exposure to carcinogens, skin cells expressed Rae-1 and H60, major histocompatibility complex-related molecules structurally resembling human MICA. Each of these is a ligand for NKG2d, a receptor expressed by cytolytic T cells and natural killer (NK) cells. In vitro, skin-associated NKG2d+ gammadelta cells killed skin carcinoma cells by a mechanism that was sensitive to blocking NKG2d engagement. Thus, local T cells may use evolutionarily conserved proteins to negatively regulate malignancy.     

NKR-P1, a signal transduction molecule on natural killer cells

Natural killer (NK) cells are a subpopulation of large granular lymphocytes characterized by densely staining azurophilic granules. NK cells are able to recognize and lyse various virally infected or neoplastic target cells without previous sensitization or major histocompatibility complex restriction. A 60-kD disulfide-linked dimer, highly expressed on NK cells, was found capable of mediating transmembrane signaling. The gene encoding this signal transduction molecule was cloned and its nucleotide sequence determined. The encoded protein showed significant homology with a number of lectin-related membrane proteins that share receptor characteristics. This protein may function as a receptor able to selectively trigger NK cell activity.     

Experimental Argyrosis: II. Treatment of Rats Receiving Silver With 2,3-Dimercaptopropanol (BAL)

The tendencies for movement of either solvent or solute in solution through a two-phased system are expressed in terms of specific (volumed) free energies. These are based on the concept of escaping tendency or free energy of a constituent component of a solution. This scheme is particularly useful to the biologist for evaluating the movement of water and solutes into cells or organs.     

大鼠心肌膜、肺、肠黏膜微血管内皮细胞静息膜电位的检测

比较大鼠心肌膜、肺、肠黏膜微血管内皮细胞静息膜电位,为内皮细胞电生理特性研究提供数据。用植块法培养大鼠心肌膜、肺、肠黏膜微血管内皮细胞,采用膜片钳放大器全细胞记录模式,分别测定3种细胞的静息膜电位。结果表明:心肌膜微血管内皮细胞的静息膜电位为(-24±4)mV;肺微血管内皮细胞的静息膜电位为(-27±6)mV;肠黏膜微血管内皮细胞静息膜电位为(-18±4)mV。3种不同组织来源的微血管内皮细胞在静息膜电位上存在异质性。     

Seeding and propagation of untransformed mouse mammary cells in the lung

The acquisition of metastatic ability by tumor cells is considered a late event in the evolution of malignant tumors. We report that untransformed mouse mammary cells that have been engineered to express the inducible oncogenic transgenes MYC and Kras(D12), or polyoma middle T, and introduced into the systemic circulation of a mouse can bypass transformation at the primary site and develop into metastatic pulmonary lesions upon immediate or delayed oncogene induction. Therefore, previously untransformed mammary cells may establish residence in the lung once they have entered the bloodstream and may assume malignant growth upon oncogene activation. Mammary cells lacking oncogenic transgenes displayed a similar capacity for long-term residence in the lungs but did not form ectopic tumors.     

小鼠骨骼肌卫星细胞的分离培养和鉴定

采用胶原酶和胰酶联用的酶消化法分离小鼠骨骼肌卫星细胞,应用差速贴壁法进行纯化,并利用RT-PCR和免疫荧光染色方法对分化前后细胞的标志基因进行鉴定。结果显示:分离出的肌卫星细胞生长状态良好,RT-PCR和免疫荧光染色显示肌卫星细胞Pax7和MyoD呈阳性表达,诱导分化形成肌管后,分化标志基因MyoG和MHC呈阳性表达。本研究成功从小鼠肌肉组织中分离出了肌卫星细胞,并具有很好的体外分化能力,可以为肌肉的发育分化和损伤修复研究提供良好的细胞模型。     

基因表达系列分析技术在植物基因表达分析中的应用

 基因表达系列分析技术 (SAGE)是一种以测序为基础 ,采用数字化分析手段 ,在转录物水平上研究细胞或组织基因表达模式的有效工具。该技术不仅能够全面地分析特定组织或细胞表达的基因 ,获得这些基因表达丰度的数量信息 ,还可比较不同组织、不同时空条件下基因表达的差异 ,从而发现新基因。SAGE技术在植物方面的应用相对较少 ,但进展很快。本文着重介绍了SAGE在植物基因表达分析中的应用 ,分析SAGE所存在的问题、改进方法及发展前景     

Mechanics of stimulated neutrophils: cell stiffening induces retention in capillaries

The effect of peptide chemoattractants on neutrophil mechanical properties was studied to test the hypothesis that stimulated neutrophils (diameter, 8 micrometers) are retained in pulmonary capillaries (5.5 micrometers) as a result of a decreased ability of the cell to deform within the capillary in response to the hydrodynamic forces of the bloodstream. Increased neutrophil stiffness, actin assembly, and retention in both 5-micrometer pores and the pulmonary vasculature were seen in response to N-formyl-methionyl-leucyl-phenylalanine. These changes were abolished in cells that had been incubated with 2 micromolar cytochalasin D, an agent that disrupts cellular actin organization. A monoclonal antibody directed at the CD11-CD18 adhesive glycoprotein complex did not inhibit the increase in stiffness or retention in pores. These data suggest that neutrophil stiffening may be both necessary and sufficient for the retention that is observed. Hence, neutrophil sequestration in lung and other capillaries in the acute inflammatory process may be the result of increased stiffness stimulated by chemoattractants.     

猪胚胎干细胞的分离培养

收集26-27d的猪胚胎分离原始生殖细胞(Primordial germ cells，PGCs)，培养在STO细胞饲养层上生长，形成EG细胞。EG细胞具有干细胞所具有的显著特性，形态，多能性和种系的延续，AKP染色阳性，并能在体外分化；分别将PGCs用三种不同的培养基培养，在形成EG细胞集落的数量和EG细胞分化上有着明显的差距，说明血清的质量和浓度以及细胞因子对干细胞的生成和增殖有着重要的作用。     

HIV-infected cells are killed by rCD4-ricin A chain

The gp120 envelope glycoprotein of the human immunodeficiency virus (HIV), which is expressed on the surface of many HIV-infected cells, binds to the cell surface molecule CD4. Soluble derivatives of recombinant CD4 (rCD4) that bind gp120 with high affinity are attractive vehicles for targeting a cytotoxic reagent to HIV-infected cells. Soluble rCD4 was conjugated to the active subunit of the toxin ricin. This conjugate killed HIV-infected H9 cells but was 1/1000 as toxic to uninfected H9 cells (which do not express gp120) and was not toxic to Daudi cells (which express major histocompatibility class II antigens, the putative natural ligand for cell surface CD4). Specific killing of infected cells can be blocked by rgp120, rCD4, or a monoclonal antibody to the gp120 binding site on CD4.     

Mixed lymphocyte reactions and tissue transplantation tolerance

The induction of tolerance of Lewis histocompatibility antigens in BN rats inoculated at birth with BNI Lewis F(1) hybrid bone marrow cells, as revealed by the prolonged survival of Lewis skin grafts, is accompanied by markedly decreased reactivity in the mixed lymphocyte interaction. Blood lymphocytes from animals inoculated with lymph node cell suspensions also display diminished proliferative reactivity to hybrid BN/Lewis cells in the interaction. However, these recipients are not tolerant of Lewis skin grafts. Blood lymphocytes from BN rats inoculated neonatally with Lewis thymocytes fail to display any level of unresponsiveness in vitro, and such animals are not tolerant of Lewis skin grafts. The results suggest that in rats skin and marrow cells have histocompatibility antigens that are absent or poorly expressed on lymph node cells and thymocytes.