Lateral Mobility of the Cell Adhesion Molecule L1 Within the Surface Membrane of Morphologically Undifferentiated and Differentiated Neuroblastoma Cells

Lateral mobility and localization in the surface membrane of the adhesion molecule L1 was studied in morphologically undifferentiated and differentiated neuroblastoma cells to gain insight into its possible association with the different molecular forms of N-CAM. In undifferentiated cells, the fraction of mobile L1 molecules is high and similar to that of N-CAM 140. Upon long-term morphological differentiation, the fraction of mobile L1 molecules is reduced by a factor of three and is similar to that of N-CAM 180, the predominant molecular form of N-CAM in differentiated neuroblastoma cells. Comparable to N-CAM 180, L1 is also preferentially accumulated at contact sites between these cells as seen by indirect immunofluorescence. These observations raise the question of whether at least part of the L1 molecules may be directly or indirectly (e.g. via N-CAM 180) linked to the cytoskeleton, thus stabilizing cell contacts between differentiated cells.     

Surface-Attached Polymer Networks Made from Cationic Poly(diitaconates): Synthesis,Surface Characterization,and Bioactivity

Facially amphiphilic polymers carrying cationic and hydrophobic groups on the same repeat unit have shown promising antimicrobial activity and biocompatibility, yet they are prone to suffer from protein adhesion which may induce biofilm formation. To overcome this problem, poly(diitaconate)-based copolymers with cationic/hydrophobic and protein-repellent/charge-neutral repeat units are synthesized. The bioactivity profile of surface-attached polymer networks made from these copolymers depends on the ratio of the cationic and charge-neutral repeat units. In all cases, the protein adhesion is substantially reduced compared to purely cationic polymers. At a 50:50 ratio, the polymer coatings are partially protein-repellent and antimicrobial, yet slightly cell toxic. At an intermediate composition of 30:70, they are still antimicrobial and the cell compatibility is substantially improved. The long-term stability of these materials still has to be determined to judge their suitability for medical applications.     

Non-responsiveness to hepatitis B vaccination in haemodialysis patients: association with impaired TCR/CD3 antigen receptor expression regulating co-stimulatory processes in antigen presentation and recognition

The study was undertaken to evaluate the relationship betweennon-responsiveness to hepatitis B (HBV) vaccination in haemodialysedpatients and HBs antigen (Ag) presentation and recognition dependingon TCR/CD3 receptors expression. We have found that the causeof the blunted response to HBV vaccination is multifactorialand seems to be associated with the following: (1) A reducednumber of TCR/CD3 antigen receptor complexes on freshly isolateduraemic CD4 T cells, especially in non-responders. (2) The bluntedproliferative response of uraemic CD4 T cells isolated fromnon-responders and stimulated for 6 days by autologous monocytespresenting HBsAg was associated with the decreased density ofthe TCR/CD3 receptors. (3) Moreover, in uraemic non-respondersthe expression of adhesion and accessory molecules on monocytes(intercellular adhesion molecule-1/ ICAM-1, HLA-DR/Ia/) wassignificantly decreased following the culture with autologousmonocytes serving as HBsAg-presenting cells. CD4 molecules andlymphocyte function antigen-1ß /LFA-1ß/on helper-inducer T cells were increased before and after theculture. (4) These findings were also associated with a diminishedbinding capacity of IL-1ß and IL-6 to their receptorson helper-inducer T cells. (5) IL-2, IFN- and IL-4 productionwas decreased in uraemic non-responders, especially after 72h of the culture. (6) Inhibited proliferation of helper-inducerT cells in uraemic non-responders was only partially reversiblein the presence of exogenous IL-1ß, IL-6, IL-2 andIFN-. (7) HLA typing of uraemic non-responders was associatedwith extended haplotype: HLA A1, B8, DR3, DR7, DQ2.     

Lymphocytes infiltrating the CNS during inflammation display a distinctive phenotype and bind to VCAM-1 but not to MAdCAM-1

The nature of inflammatory lymphocytes recruited to the CNShas been studied in a model of chronic inflammation. Injectionof killed Corynebacterlum parvum into the cortex of the mousebrain produces a circumscribed inflammatory cellular infiltratearound the injection site, and recruited mononuclear inflammatorycells (IC) can be isolated for flow cytometric analysis. Themajority of IC were T cells. In comparison with the predominantnaive population of mesenteric lymph node T cells, IC T cellsexpress much higher levels of CD44, LFA-1 and ICAM-1, and lowerlevels of CD45RB, features commonly associated with memory (previouslyactivated) cells. In addition, in contrast to the L-selectin⁺6-integrin^low phenotype of naive lymph node T cells, IC T cellslacked L-selectin and were 6-integrin^–. Mac-1, recentlyproposed as another marker of memory T cell differentation,was not displayed by IC T cells, suggesting that Mac-1 expressionmay be heterogeneous among memory T cell subsets. A subset ofmesenteric lymph node (MLN) T cells, probably representing activatedT cells undergoing the naive to memory transition, but not ofIC T cells, expressed high levels of 6-, ß7- and E-integrin.IC and MLN naive T cells expressed comparable levels of 4-integrin,but IC T cells stain poorly with anti-ß7 mAbs andwith mAb DATK 32, specific for the 4ß7 heterodimericlymphocyte homing receptor for the mucosal addressin MAdCAM-1,suggesting that these inflammatory cells express more 4ß1than 4ß7. Consistent with this, in in vitro adhesionassays, brain IC bound better than MLN cells to the 4ß1integrin ligand VCAM-1 and the LFA-1 ligand ICAM-1 but adheredvery poorly to the 4ß7 ligand MAdCAM-1. These findingsare consistent with and extend previous immunohistological studiesof T cells in murine experimental autoimmune encephalomyelitis,and demonstrate a distinctive phenotype for lymphocytes beingpresent in the chronically inflamed brain.     

Soluble E-selectin correlates with disease activity in cyclosporin A-treated patients with atopic dermatitis

BACKGROUND: The expression of adhesion molecules on endothelial cells regulates leukocyte migration. The level of soluble adhesion molecules which are shed into the circulation is known to reflect the degree of inflammation, and this level can therefore be used as an indicator of disease activity. The objective of this study was first to investigate the relationship between sE-selectin levels and disease activity parameters (scores of extent, severity, itch, and sleep) in atopic dermatitis (AD) patients, and second to determine the effect of therapy with an immunosuppressive drug (cyclosporin A) on sE-selectin levels. METHODS: Fourteen patients with severe AD and 41 healthy controls were studied. sE-selectin was measured by ELISA both 2 weeks before therapy with cyclosporin A and after 16 weeks of treatment. RESULTS: At baseline, the level of sE-selectin was significantly higher in patients with AD than in healthy control subjects (P<0.0001). After treatment of AD with cyclosporin A, there was a significant reduction of the sE-selectin levels (P<0.0001). In addition, changes in sE-selectin levels significantly correlated with changes in disease activity parameters such as severity (P<0.002) and extent of disease (P<0.049). CONCLUSIONS: Soluble E-selectin is a new serologic marker in AD which reflects disease activity. Therefore, soluble E-selectin may be a useful parameter in the monitoring of this disease.     

LIF对体外培养小鼠孕早期胚胎发育及ICAM-1表达的影响

目的研究白血病抑制因子（ＬＩＦ）在胚胎发育中的作用并探讨其参与胚泡着床的机制。方法收集昆明种小鼠的单细胞受精卵,连续培养１２０ｈ,观察不同浓度ＬＩＦ对胚胎发育的影响;用免疫印迹法测定培养液中细胞间粘附分子（ＩＣＡＭ－１的表达水平。结果ＬＩＦ在０．１～１０ｎｇ／ｍｌ浓度之间对胚胎发育有促进作用,其作用在桑椹胚及胚泡期最明显（Ｐ＜０．０５）;ＬＩＦ增加胚胎ＩＣＡＭ－１的表达,其作用在０．１ｎｇ／ｍｌ浓度时最强,并随着浓度的增加而减弱。结论适应浓度的ＬＩＦ可促进胚胎发育,增加ＩＣＡＭ－１的表达,从而参与胚胎着床过程。     

膀胱癌上皮细胞粘附分子蛋白表达的意义

目的 探讨上皮细胞粘附分子（Ｅ－ＣＤ）表达情况对判断膀胱癌恶性程度、复发及预后的意义。方法 采用免疫组织化学方法对５４例膀胱癌标本中Ｅ－ＣＤ的表达情况进行研究。结果Ｅ－Ｃ原表达情况与膀胱癌的病理分级、分期均有密切关系。（ｘ＾２＝６．６５,Ｐ〈０．０５,Ｘ＾２＝７．１５,Ｐ〈０．０１）。Ｅ－ＣＤ的的民光癌的近期昨发及不良预后有关。（Ｘ＾２＝４．８８,Ｐ〈０．０５;Ｌｏｎｇ－Ｒａｎｋ ｔｅｓｔ;ｘ＾２     

可溶性血管细胞黏附分子1在妊高征发病中的作用

目的　研究可溶性血管细胞黏附分子 1(solublevascularcelladhesionmolecule - 1,sVCAM - 1)在妊高征发病中的作用。方法　用酶联免疫吸附法 (ELISA)测定 6 7例孕妇血清中sVCAM - 1水平 ,其中正常妊娠组 15例 ,妊高征组 5 2例。结果　中、重度妊高征患者血中sV CAM - 1水平显著高于正常妊娠组 (P <0 .0 1) ;轻度妊高征患者与正常妊娠组相比 ,虽无统计学差异 ,但有升高趋势 ;妊高征组产后该指标下降 ,与正常妊娠组比较无显著性差异 (P >0 0 5 )。sVCAM - 1浓度与平均动脉压呈正相关 (r =0 .5 4 2 ,P <0 .0 1)。结论　妊高征患者血中sVCAM - 1水平升高 ,表明内皮细胞损伤在妊高征的发病中起重要作用。     

透明质酸在宫颈上皮及宫颈癌组织中的表达

目的 :探讨透明质酸 (HA)在正常宫颈上皮及宫颈癌中的表达及其与肿瘤发生发展的关系。方法 :用免疫组化法检测 5 9例宫颈浸润癌、35例宫颈上皮内瘤样病变 (CIN)及11例正常宫颈组织中HA和CD4 4v6的表达。结果 :正常宫颈上皮不表达HA。慢性炎症者上皮底层细胞以及细胞间质表达HA ,随病变加重及CIN发生 ,HA表达增强。癌旁组织的上皮细胞HA呈强阳性表达 ,伴有基质HA强阳性染色。癌细胞HA阳性率为 6 7.2 7% ,与病理类型有关 ,角化癌高表达 ,而腺癌不表达 ,在低分化鳞癌中多见不规则灶性HA阴性区。宫颈鳞癌的肿瘤基质HA表达普遍增强。肿瘤基质的HA表达与CD4 4v6呈正相关。结论 :正常宫颈上皮不表达HA ,但炎症与致瘤因素可促使HA表达 ,HA的代谢失衡可能与宫颈癌的发生及浸润行为有关     

Hyperoxia-induced apoptosis of AEC Ⅱ in premature rats by inhibiting expression of focal adhesion kinase

Objective To explore the role of focal adhesion kinase (FAK) in hyperoxia-apopto- sis of type Ⅱ alveolar epithelial cells (AEC Ⅱ s) of premature rats. Methods AEC Ⅱ from prema- ture rat lungs were cultured and randomly assigned to air group and hyperoxia group. After exposed to hyperoxia for 6, 12, 24 and 48 h, apoptosis rate of AEC Ⅱ were analyzed by flow cytometry with an- nexin-Ⅴ/propidium iodine (PI) double staining. FAK mRNA and FAK and fAK-Tyr397 peptide were detected by RT-PCR and Western blot, respectively. Results Positive cells of Annexin-Ⅴ+ / PI- in AEC Ⅱ after 6,12,24 and 48 h of hyperoxia exposure were significantly decreased, and the maximal apoptosis rate of AEC Ⅱ (stained of Annexin-Ⅴ+ / PI- ) was found in the hyperoxia group at 12 h (23.83%±4.43%). Compared to the air group, the expression of FAK mRNA and of FAK de- creased markedly and progressively in hyperoxia groups at 12, 24 and 48 h(P<0. 05). Conclusions Decreased expression of FAK induced by hyperoxia is likely to contribute to the apoptosis and neco-z sis of AEC Ⅱ.