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排序方式: 共有221条查询结果,搜索用时 15 毫秒
1.
Nikolas K. Haass D. Ripperger E. Wladykowski P. Dawson P. A. Gimotty C. Blome F. Fischer P. Schmage I. Moll Johanna M. Brandner 《Histochemistry and cell biology》2010,133(1):113-124
Melanoma depends on, interacts with and reacts to the stroma in which it is embedded, including fibroblasts, extracellular
matrix, endothelial cells and immune cells. However, the impact of melanoma on the epidermal tumor microenvironment—the multilayered
epithelium of the skin—is poorly understood. Gap junctions are essential for intercellular communication and involved in proliferation,
differentiation and homeostasis of keratinocytes. We have shown previously that the gap junction proteins connexin 26 and
30 (Cx26 and Cx30) are induced in the epidermal tumor microenvironment of skin cancers including melanoma. This study compares
the extent of Cx26, Cx30 and Cx43 expression in the epidermal microenvironment of melanocytic nevi and melanomas and its association
with melanoma thickness, proliferative index of the tumor and its microenvironment, and with 5-year metastasis and survival.
We found that induction of Cx26 and Cx30 cell–cell border expression in the epidermal tumor microenvironment correlates to
malignancy. Importantly, there was a significant correlation of tumor thickness with the vertical epidermal Cx26 and Cx30
expression pattern and the horizontal Cx26 dissemination. Furthermore, horizontal Cx26 expression correlated with metastasis.
Vertical epidermal expression patterns of Cx26 and Cx30 significantly correlated with the proliferative index in the epidermal
tumor microenvironment but not with the proliferative index in the tumor. In contrast, Cx43 did not correlate with malignancy,
thickness or proliferative index. In summary, here we show for the first time a significant association between the progression
of melanoma and alterations in its epithelial tumor microenvironment. 相似文献
2.
Distribution and functional role of laminin during induction of the embryonic axis in the chick embryo 总被引:2,自引:0,他引:2
Laminin is a major glycoprotein of basement membranes and has been shown to promote cell adhesion, and movement of various nonepithelial cells and tumour cells. Using antibodies to laminin in paraffin sections and cultured embryos, we have studied the distribution of laminin and its involvement in the first morphogenetic events, beginning with the first extensive cellular migrations and interactions that result in the induction of the primitive streak (PS) and of the neural plate in the early chick embryo. Laminin immunogold labeling was not detected in the blastoderm at stage X. At stage XIII, laminin immunoreactivity was detected at the ventral surface of the epiblast and in the entire hypoblast. The intense labeling of the hypoblast indicated that these cells are active in laminin synthesis. Extracellular matrix (ECM) started accumulating as the first embryonic spaces were forming, before the morphogenetic movements of gastrulation were initiated. Immunogold labeling revealed a punctate pattern of laminin distribution in the ECM in the blastocoele, and in the space below the neural plate. Laminin, which is a multidomain molecule known to interact with other molecules of the ECM and with the cell surface, could serve as the scaffold for highly specific contact points of migrating cells and for the folding of epithelial sheets during this time in the developing embryo. We incubated blastoderms at stages X and XIII with laminin antibodies (1:30 dilution) for 4 h, then cultured the blastoderms further in plain egg albumin. The laminin antibodies did not interfere with triggering of PS cell movements, but perturbed the normal migration pattern of these cells. A normal PS did not form and, as a consequence, the embryonic axis was not induced.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
4.
Summary The component areas of chick blastula show differential expression of heat shock genes. The area opaca (ao), marginal zone (mz) and central area (ca) components of the epiblast display distinct quantitative and minor qualitative differences in the heat-induced and heat-repressible proteins, but are clearly different from the primary hypoblast (endoderm) in their expression of a given stress protein (hsp) as a response to heat shock. The major proteins synthesized in the component areas of epiblast in response to heat shock include hsp 18, 24, 70 and 89 Kd. Two-dimensional electrophoresis shows that each of these proteins consists of multiple charged species. The hypoblast expresses only hsp 70 Kd at non-significant levels and shows marked inhibition in the level of synthesis of heat-shock-repressible proteins. Heat shock during the blastula stage results in an increase in the size of the blastoderm and disrupts normal embryonic development. The heat shock genes provide an important molecular marker, which attests to regional specification in the chick blastula. 相似文献
5.
The competence of stage XIII chick epiblast which under the influence of an inductive hypoblast is directed to form a normal primitive streak, is affected by 5-bromodeoxyuridine (BUdR). The BUdR-treated epiblast forms an atypical primitive streak and no axial mesoderm. However, a nonorganized mesenchymal layer is formed between the epiblast and the hypoblast, and atypical neural tissue in the epiblast. BUdR interferes neither with hypoblast formation nor with its inductivity even when blastoderms are treated with BUdR as early as uterine stage VIII and later. 相似文献
6.
Summary In early chick blastoderm at stage XIII, the interaction of the hypoblast with the epiblast triggers on the epiblast the first extensive cellular migrations, which result in formation of the primitive streak, the source of the axial mesoderm. During this period, extracellular material (ECM) is secreted and assembled into an organized network in the extracellular spaces and is implicated in regulating the behaviour of the cells that contact it. The first cellular migrations and inductions are inhibited when early chick blastoderm is treated with the glycosylation-perturbing ionophore monensin. The difference in amount and in organization of ECM between monensin-treated embryos and control embryos is striking. Even blastoderms at stage X, which are essentially free of ECM, show extensive ECM after monensin treatment. Monensin produces a substantial change in the polypeptide pattern with the induction or marked accentuation of multiple charged species (isoforms) of polypeptides different from those present in the control embryos. The interference of monensin with the migration and induction mechanisms is permanent in embryos before the primitive streak (PS) stage, and it seems that the respective signals or the sensitivity of the epiblast/hypoblast cells to them must be very stage specific. Monensin-treated embryos probably secrete abnormal ECM that does not provide the proper conditions for the hypoblast to interact with the epiblast cells. 相似文献
7.
Anthony Kwok Brett P. Lyons Nikolas J. Hodges Tim P. Bean 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2013,750(1-2):86-91
Estuarine and coastal habitats are known to be polluted by a range of chemical contaminants from both industrial and domestic sources. Blue mussels (Mytilus spp.), which inhabit these areas, are widely used as bio-indicators in eco-toxicological studies, because of their sedentary nature and their ability to bio-accumulate contaminants. The analysis of DNA damage in mussel haemocytes is a valuable tool for biomonitoring but sampling issues related to storage, handling and transportation have often limited its application in large-scale monitoring programmes. This study uses a trial and error method to evaluate and validate a suitable protocol for cryopreservation of mussel haemocytes, thereby allowing material collected in the field to be analysed later under controlled laboratory conditions. Three different cell-culture media, i.e. Leibovitz-15, Hank's balanced salt solution and mussel physiological saline, along with four different cryoprotectants, i.e. dimethyl sulphoxide (10% and 20%), 1,2-propanediol (10%), ethylene glycol (10%) and glycerol (10%) were tested to assess their suitability for cryopreservation of mussel haemocytes for analysis in the comet assay. Experimental studies where mussel haemocytes were also exposed to UV radiation or benzo(a)pyrene were conducted in order to mimic environmental stresses and to verify the effectiveness of newly defined cryopreservation protocols. The comet assay was used to demonstrate that mussel haemocytes could be preserved at cryogenic temperatures for a month without altering levels of DNA damage, which could possibly be used for lab or field studies where time constraints or facilities do not allow instant analysis. 相似文献
8.
Yue Yang Christine Shiao Jake Frederick Hemingway Nikolas L. Jorstad Bryan Richard Shalloway Rubens Chang C. Dirk Keene 《PloS one》2013,8(6)
Alzheimer''s disease (AD) is an age-related condition characterized by accumulation of neurotoxic amyloid β peptides (Aβ) in brain and retina. Because bone marrow transplantation (BMT) results in decreased cerebral Aβ in experimental AD, we hypothesized that BMT would mitigate retinal neurotoxicity through decreased retinal Aβ. To test this, we performed BMT in APPswe/PS1ΔE9 double transgenic mice using green fluorescent protein expressing wild type (wt) mice as marrow donors. We first examined retinas from control, non-transplanted, aged AD mice and found a two-fold increase in microglia compared with wt mice, prominent inner retinal Aβ and paired helical filament-tau, and decreased retinal ganglion cell layer neurons. BMT resulted in near complete replacement of host retinal microglia with BMT-derived cells and normalized total AD retinal microglia to non-transplanted wt levels. Aβ and paired helical filament-tau were reduced (61.0% and 44.1% respectively) in BMT-recipient AD mice, which had 20.8% more retinal ganglion cell layer neurons than non-transplanted AD controls. Interestingly, aged wt BMT recipients also had significantly more neurons (25.4%) compared with non-transplanted aged wt controls. Quantitation of retinal ganglion cell layer neurons in young mice confirmed age-related retinal degeneration was mitigated by BMT. We found increased MHC class II expression in BMT-derived microglia and decreased oxidative damage in retinal ganglion cell layer neurons. Thus, BMT is neuroprotective in age-related as well as AD-related retinal degeneration, and may be a result of alterations in innate immune function and oxidative stress in BMT recipient mice. 相似文献
9.
Jan Richter Christakis Panayiotou Christina Tryfonos Dana Koptides Maria Koliou Nikolas Kalogirou Eleni Georgiou Christina Christodoulou 《PloS one》2016,11(1)
In order to improve clinical management and prevention of viral infections in hospitalised children improved etiological insight is needed. The aim of the present study was to assess the spectrum of respiratory viral pathogens in children admitted to hospital with acute respiratory tract infections in Cyprus. For this purpose nasopharyngeal swab samples from 424 children less than 12 years of age with acute respiratory tract infections were collected over three epidemic seasons and were analysed for the presence of the most common 15 respiratory viruses. A viral pathogen was identified in 86% of the samples, with multiple infections being observed in almost 20% of the samples. The most frequently detected viruses were RSV (30.4%) and Rhinovirus (27.4%). RSV exhibited a clear seasonality with marked peaks in January/February, while rhinovirus infections did not exhibit a pronounced seasonality being detected almost throughout the year. While RSV and PIV3 incidence decreased significantly with age, the opposite was observed for influenza A and B as well as adenovirus infections. The data presented expand our understanding of the epidemiology of viral respiratory tract infections in Cypriot children and will be helpful to the clinicians and researchers interested in the treatment and control of viral respiratory tract infections. 相似文献
10.
Anna-Lena Volckmar Chung Ting Han Carolin Pütter Stefan Haas Carla I. G. Vogel Nadja Knoll Christoph Struve Maria G?bel Katharina Haas Nikolas Herrfurth Ivonne Jarick Harald Grallert Annette Schürmann Hadi Al-Hasani Johannes Hebebrand Sascha Sauer Anke Hinney 《PloS one》2016,11(2)