|
| ||
|
|
||
Cell Area (cell + area)
Selected AbstractsOsteoblast Adhesion and Proliferation on Poly(3-octylthiophene) Thin FilmsMACROMOLECULAR BIOSCIENCE, Issue 3 2010Charlene Rincón Abstract In this study we assessed the suitability of semiconducting P3OT thin films (30,nm) to sustain attachment, spreading, and proliferation of MC3T3-E1 osteoblasts. Cell area correlated with surface wettability: area was larger on the more hydrophilic surface (TCPS) and lower on the more hydrophobic surface (P3OT). Cells were rounder, characterized by higher circularity values, on TCPS and Si compared to P3OT. P3OT proliferation rate at 24,h fell twofold after 48,h, then recovered at 72,h to a value significantly higher than that on TCPS. Presoaking experiments showed no evidence of cytotoxic effects or leachants from P3OT. Overall, we conclude that P3OT is a viable substrate for osteoblast attachment and proliferation. [source] The effect of combined simulated microgravity and microgrooved surface topography on fibroblastsCYTOSKELETON, Issue 3 2007W. A. Loesberg Abstract This study evaluated in vitro the differences in morphological behaviour between fibroblast cultured on smooth and microgrooved substrata (groove depth: 0.5 ,m, width: 1, 2, 5, and 10 ,m), which were subjected to simulated microgravity. The aim of the study was to clarify which of these parameters was more dominant to determine cell behaviour. Morphological characteristics were investigated using scanning electron microscopy and fluorescence microscopy in order to obtain qualitative information on cell alignment and area. Confocal laser scanning microscopy visualised distribution of actin filaments and focal adhesion points. Finally, expression of collagen type I, fibronectin, and ,1- and ,1-integrin were investigated by PCR. Microscopy and image analysis showed that the fibroblasts aligned along the groove direction on all textured surfaces. On the smooth substrata, cells had spread out in a random fashion. The alignment of cells cultured on grooved surfaces decreased under simulated microgravity, especially after 24 h of culturing. Cell surface area on grooved substrata were significantly smaller than on smooth substrata, but simulated microgravity on the grooved groups resulted in an enlargement of cell area. ANOVA was performed on all main parameters: topography, gravity force, and time. In this analysis, all parameters proved significant. In addition, gene levels were reduced by microgravity particularly those of ,1-integrin and fibronectin. From our data it is concluded that the fibroblasts primarily adjust their shape according to morphological environmental cues like substratum surface whilst a secondary, but significant, role is played by microgravity conditions. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] Synthetic matrix metalloproteinase inhibitor decreases early cardiac neural crest migration in chicken embryosDEVELOPMENTAL DYNAMICS, Issue 4 2002D.H. Cai Abstract During early embryonic development, cardiac neural crest (NC) cells emerge from the forming neural tube, migrate beneath the ectoderm, enter the pharyngeal arches, and subsequently participate in the septation of the heart. Like tumor cells, NC cells penetrate through basement membranes and invade extracellular matrix during their emigration and migration and, therefore, are liable to use similar invasive mechanisms. Matrix metalloproteinases (MMPs) are a family of zinc proteolytic enzymes known to be important in cell migration and invasion of normal and metastatic cells. In an earlier study, we found that the spatial and temporal distribution pattern of MMP-2 positively correlates with cardiac NC migration, suggesting MMP enzymatic activity may be important in mediating cardiac cell NC migration. To test this hypothesis, a synthetic MMP inhibitor, KB8301, was used to block MMP enzymatic activity during in vitro and in vivo cardiac NC cell migration in chick embryos. Injection of KB8301 into the cell-free space adjacent to the neural tube at the level of the second somite before the NC cells emigrated caused major morphologic anomalies in embryos and disrupted cardiac NC morphogenesis. Unilateral injection of KB8301 at lower concentrations, significantly decreased cardiac NC migration on the injected side compared with the noninjected side and compared with that of the injected controls. This decrease correlated with a decrease in MMP activity in the embryos and was not attributable to differences in embryo size or rate of embryonic development after injection. KB8301 also significantly decreased the rate of NC cell motility and distance NC cells migrated from explanted neural tubes and increased cell area and perimeter. These data suggest that MMP enzymatic activity is an important mediator of early cardiac NC migration and that perturbation of endogenous MMP activity may lead to NC-related congenital defects. © 2002 Wiley-Liss, Inc. [source] Effect of elevated homocysteine on cardiac neural crest migration in vitroDEVELOPMENTAL DYNAMICS, Issue 2 2002Philip R. Brauer Abstract A positive correlation between elevated maternal homocysteine (Hcys) and an increased risk of neural tube, craniofacial, and cardiac defects is well known. Studies suggest Hcys perturbs neural crest (NC) development and may involve N-methyl-D-aspartate (NMDA) receptors (Rosenquist et al., 1999). However, there is no direct evidence that Hcys alters NC cell behavior. Here, we evaluated the effect of Hcys on cardiac NC cell migratory behavior in vitro. Neural tube segments from chick embryos treated in ovo with or without Hcys were placed in culture and the migratory behavior of emigrating NC cells was monitored. Hcys significantly increased in vitro NC cell motility at all embryonic stages examined. NC cell surface area and perimeter were also increased. However, the relative distance NC cells migrated from their original starting point only increased in NC cells treated in ovo at stage 6 or at the time neural tube segments were cultured. Cysteine had no effect. NMDA mimicked Hcys' effect on NC motility and migration distance but had no effect on cell area or perimeter. The noncompetitive inhibitor of NMDA receptors, MK801+, significantly inhibited NC cell motility, reduced migration distance, and also blocked the effects of NMDA and Hcys on NC motility and migratory distance in vitro. A monoclonal antibody directed against the NMDA receptor immunostained NC cells in vitro and, in western blots, bound a single protein with the appropriate molecular weight for the NMDA receptor in NC cell lysates. These data are consistent with the hypothesis that a Hcys-sensitive NMDA-like receptor is expressed by early emigrating NC cells or their precursors, which is important in mediating their migratory behavior. Perturbation of this receptor may be related to some of the teratogenic effects observed with elevated Hcys. © 2002 Wiley-Liss, Inc. [source] Intrasplenic trafficking of natural killer cells is redirected by chemokines upon inflammationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2008Claude Grégoire Abstract The spleen is a major homing site for NK cells. How they traffic to and within this site in homeostatic or inflammatory conditions is, however, mostly unknown. Here we show that NK cells enter the spleen through the marginal sinus and home to the red pulp via a pertussis toxin-insensitive mechanism. Upon inflammation induced by poly(I:C) injection or mouse cytomegalovirus infection, many NK cells left the red pulp while others transiently entered the white pulp, predominantly the T cell area. This migration was dependent on both CXCR3 and CCL5, suggesting a synergy between CXCR3 and CCR5, and followed the path lined by fibroblastic reticular cells. Thus, the entry of NK cells in the white pulp is limited by the expression of pro-inflammatory chemokines. This phenomenon ensures the segregation of NK cells outside of the white pulp and might contribute to the control of immunopathology. [source] Fibronectin Functionalized Hydroxyapatite Coatings: Improving Dermal Fibroblast Adhesion In Vitro and In Vivo,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Catherine J. Pendegrass Skin-penetrating devices including intraosseous transcutaneous amputation prostheses (ITAP) and external fixator pins rely on a skin-implant seal to prevent infection. In this study, we assess the effectiveness of fibronectin (Fn) functionalized hydroxyapatite (HA) coatings for promoting dermal fibroblast and dermal tissue attachment and ingrowth in vitro and in vivo. By measuring the number of focal adhesions per unit cell area we have demonstrated that HA significantly promotes dermal fibroblast attachment compared with titanium alloy. Dermal fibroblast attachment is promoted further using Fn functionalized HA coatings incorporated into an implant design with 700,µm pores, which significantly increased dermal tissue ingrowth and attachment compared with non-functionalized HA and titanium alloy controls incorporating 500 or 1000,µm pores. We postulate that Fn functionalized HA coatings applied to transdermal implants may promote and sustain the skin-implant interface and assist in preventing infection long term. [source] Apoptosis in oral lichen planusEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2001Evelyn Neppelberg Apoptotic cell death may be a contributory cause of basal cell destruction in oral lichen planus (OLP). Therefore, the purpose of this study was to investigate the rate of apoptosis in OLP and the expression of two proteins (FasR and FasL) regulating this process. Biopsies from 18 patients with histologically diagnosed OLP were investigated, with comparison to normal oral mucosa of healthy persons. For visualisation of DNA fragmentation, the TUNEL method was used. In order to characterise the infiltrating cell population (CD3, CD4, CD8) and expression of FasR and FasL, we used an immunohistochemical technique. The results showed that T cells dominated in the subepithelial cell infiltrate. Within the epithelium the apoptotic cells were confined to the basal cell layer, and more apoptotic cells were seen in areas with basal cell degeneration and atrophic epithelium. There was a prominent expression of FasR/FasL in OLP, with a rather uniform distribution throughout the inflammatory cell infiltrate. In the epithelium, the FasR/FasL expression was more abundant in the basal cell area compared to the suprabasal cell layer. In conclusion, apoptosis within the epithelium is significantly increased in situ in OLP compared to normal oral mucosa, and seems to be related to the epithelial thickness. [source] DIFFERENT CELL SIZE AND CELL NUMBER CONTRIBUTION IN TWO NEWLY ESTABLISHED AND ONE ANCIENT BODY SIZE CLINE OF DROSOPHILA SUBOBSCURAEVOLUTION, Issue 3 2003Federico C. F. Calboli Abstract Latitudinal genetic clines in body size occur in many ectotherms including Drosophila species. In the wing of D. melanogaster, these clines are generally based on latitudinal variation in cell number. In contrast, differences in wing area that evolve by thermal selection in the laboratory are in general based on cell size. To investigate possible reasons for the different cellular bases of these two types of evolutionary response, we compared the newly established North and South American wing size clines of Drosophila subobscura. The new clines are based on latitudinal variation in cell area in North America and cell number in South America. The ancestral European cline is also based on latitudinal variation in cell number. The difference in the cellular basis of wing size variation in the American clines, which are roughly the same age, together with the similar cellular basis of the new South American cline and the ancient European one, suggest that the antiquity of a cline does not explain its cellular basis. Furthermore, the results indicate that wing size as a whole, rather than its cellular basis, is under selection. The different cellular bases of different size clines are most likely explained either entirely by chance or by different patterns of genetic variance,or its expression,in founding populations. [source] Differential long-term neurotoxicity of HIV-1 proteins in the rat hippocampal formation: A design-based stereological studyHIPPOCAMPUS, Issue 2 2008Sylvia Fitting Abstract The human immunodeficiency virus type 1 (HIV-1) proteins, gp120 and Tat, are believed to play a role in mediating central nervous system (CNS) pathology in HIV-1 infected patients. Using design-based stereology, we examined the role of neonatal intrahippocampal injections of gp120 and Tat on the adult hippocampus (,7˝ month). Postnatal day (P)1-treated Sprague-Dawley rats were bilaterally injected with vehicle (VEH, 0.5 ,l sterile buffer), gp120 (100 ng), Tat (25 ,g) or combined gp120 + Tat (100 ng + 25 ,g). Using Nissl-stained tissue sections, we quantified total neurons in five subregions of the rat hippocampus [granual layer (GL), hilus of the dentate gyrus (DGH), cornu ammonis fields (CA)2/3, CA1, and subiculum (SUB)], and total glial cells (astrocytes and oligodendrocytes) in two subregions (DGH and SUB). Estimates of cell area and cell volume were taken in the DGH. There was a significant reduction of neuron number in the CA2/3 subfield by Tat and gp120, and a significant reduction in the DGH by Tat only. For glial cells, numbers of astrocytes in the DGH and SUB were increased by the Tat protein, whereas no effects were noted for gp120. Finally, for oligodendrocytes Tat increased cell number in the DGH but not in any other region; gp120 had no detectable effect in any brain region. Estimates of cell area and cell volume of the three different cell types revealed no significant differences between treatments. Collectively, these results suggest differential effects of gp120 and Tat on the estimated total number of neurons, as well as on the number of glial cells. © 2007 Wiley-Liss, Inc. [source] A BTOP model to extend TOPMODEL for distributed hydrological simulation of large basinsHYDROLOGICAL PROCESSES, Issue 17 2008Kuniyoshi Takeuchi Abstract Topography is a dominant factor in hillslope hydrology. TOPMODEL, which uses a topographical index derived from a simplified steady state assumption of mass balance and empirical equations of motion over a hillslope, has many advantages in this respect. Its use has been demonstrated in many small basins (catchment areas of the order of 2,500 km2) but not in large basins (catchment areas of the order of 10 000,100 000 km2). The objective of this paper is to introduce the Block-wise TOPMODEL (BTOP) as an extension of the TOPMODEL concept in a grid based framework for distributed hydrological simulation of large river basins. This extension was made by redefining the topographical index by using an effective contributing area af(a) (0,f(a),1) per unit grid cell area instead of the upstream catchment area per unit contour length and introducing a concept of mean groundwater travel distance. Further the transmissivity parameter T0 was replaced by a groundwater dischargeability D which can provide a link between hill slope hydrology and macro hydrology. The BTOP model uses all the original TOPMODEL equations in their basic form. The BTOP model has been used as the core hydrological module of an integrated distributed hydrological model YHyM with advanced modules of precipitation, evapotranspiration, flow routing etc. Although the model has been successfully applied to many catchments around the world since 1999, there has not been a comprehensive theoretical basis presented in such applications. In this paper, an attempt is made to address this issue highlighted with an example application using the Mekong basin. Copyright © 2007 John Wiley & Sons, Ltd. [source] An experimental and mathematical study of efforts of a novel photovoltaic-Trombe wall on a test roomINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6 2008Ji Jie Abstract A novel photovoltaic-Trombe wall (PV-TW) is proposed and investigated experimentally and theoretically in this paper. The PV-TW was installed at the south-facing external wall of an environmental chamber that carried two identical test rooms. Both of the test rooms have a double window of the same size. One test room was installed with the PV-TW (known as the PV-TW room), and the other without PV-TW (known as the reference room). The influence of the PV-TW on the thermal environment of the test room was investigated under different operating conditions. The experimental results show the dual benefits of the PV-TW system: improving the room thermal condition and at the same time generating electricity. Compared with the reference room, the maximum indoor temperature was found to be 5,7°C higher in winter, and the daily electrical output reached about 0.3,kWh with a PV cell area of 0.72,m2. Also, a detailed model is given to evaluate the performance of PV-TW theoretically, and the PV-TW room is simulated under one certain operating condition. The simulated and measured air temperatures of PV-TW room are found to be in good agreement. Copyright © 2007 John Wiley & Sons, Ltd. [source] Quantitation of cytological parameters of malignant lymphocytes using computerized image analysisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2008S. A. HAMID JAHANMEHR Summary Computerized image analysis may add to morphological evaluation by turning qualitative data into quantitative values. In this study, image analysis program was used to quantitate cytological parameters of lymphocytes in B-cell lymphoproliferative disorders. Chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL) and B-cell prolymphocytic leukemia (B-PLL) were selected to represent typically small, medium, and large-sized lymphocytes, respectively. Image analysis was performed to determine the morphological parameters. A set of measurements was generated for quantitation of total cell area, cell diameter, cytoplasm area, nuclear area, nuclear/cell ratio, and nuclear density. The quantitated parameters substantiated morphological characteristics of the tumor cells. Comparative assessments demonstrated that CLL, MCL, and PLL can be differentiated by the quantitative descriptors. The results from image analysis may assist in defining morphological criteria and in developing quantitative cell morphology. [source] Determination of peripheral blood stem cells by the Sysmex SE-9500INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2001Liming Peng The Sysmex SE-9500 automated haematology analyser provides an estimate of immature cells, referred to as ,haematopoietic progenitor cells' (HPC). The aim of this study was to evaluate the reliability and usefulness of the SE-9500 HPC parameter as compared with the CD34 + cell count and to determine whether the HPC count was of value in predicting the optimal harvesting time for peripheral blood stem cells (PBSC). Studies were performed on 112 samples from 21 patients with haematological malignancies and 13 healthy donors undergoing progenitor cell mobilisation. Coefficients of variation for the HPC count were 30%, 23.8%, 12.4% and 8.3% respectively for samples with low (4 × 106/l), medium (13 × 106/l), high (250 × 106/l) and very high (2413 × 106/l) counts. There was good linearity for HPC measurement in both peripheral blood (PB) and purified CD34 + cell suspensions (r > 0.995), and no detectable carryover was observed. There was an acceptable correlation between HPC and CD34 + cell counts for PB samples (r=0.669) and for CD34 + cell suspensions (r=0.859). Analysis of purified CD34 + cells using the SE-9500 HPC mode revealed that they appear both in the blast cell area and the immature granulocyte area of the analyser cell display. Quantitation of CD34 + cells and HPC during PBSC mobilisation showed good agreement between these parameters with regard to the optimal time for PBSC harvesting. These findings suggest that HPC counting with the Sysmex SE-9500 may be clinically useful for optimising the timing of PBSC collection. [source] Demonstration of Birbeck (Langerhans cells) granules in the normal chicken epidermisJOURNAL OF ANATOMY, Issue 4 2001ARMANDO PÉREZ-TORRES Mammalian Langerhans cells (LC) are epidermal dendritic cells which originate in bone marrow and migrate toward the T cell area of lymph nodes, where they act as professional antigen-presenting cells. A variety of cell surface markers, such as the ectoenzyme adenosine triphosphatase (ATPase), Ia and CD1a antigens, have been used extensively to identify LC. Ultrastructural identification of this cell type in the mammalian epidermis is made by the demonstration of a typical and unique cytoplasmic organelle, the Birbeck granule (BG). Although we had earlier demonstrated the coexpression of ATPase and Ia antigens on epidermal dendritic cells of the chicken epidermis, the presence of the BG has not previously been documented. The aim of the present study was to investigate whether chicken epidermal LC-like cells possess an organelle similar to the BG, and thus to complete their identification. Our findings are the first demonstration of characteristic rod-shaped, racket-shaped and disc-shaped intracytoplasmic organelles, morphologically similar to the mammalian BG, in avian LC. [source] ORIGINAL ARTICLE: Intestinal villus histological alterations in broilers fed dietary dried fermented gingerJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2010T. Incharoen Summary To evaluate the effect of dietary dried fermented ginger (DFG) on intestinal villous histological alteration and growth performance, 64 Marshall Chunky male broilers were divided into four groups, each with four replicates of four chickens. Birds were fed the basal commercial mash diet supplemented with DFG at 0 (control), 5, 10 and 20 g/kg for 42 days. With increasing dietary DFG levels, feed intake tended to decrease and significantly decreased in the 20 g/kg DFG group (p < 0.05). Weight gain was higher in all the DFG groups, with the highest in the 10 g/kg DFG group (p < 0.05), resulting in an improved feed efficiency in all the DFG groups. Intestinal villus height, villus area, cell area and cell mitosis in all the intestinal segments were higher in all the DFG groups than in the control group. Protuberated cells and cell clusters were found in all the DFG groups, suggesting that the intestinal villi and cells might be hypertrophied. The present results indicate that dietary DFG can be used as a natural feed additive to induce broiler growth performance as a result of stimulation of morphological maturation and in consequence intestinal function. [source] Microtopography of metal surfaces influence fibroblast growth by modifying cell shape, cytoskeleton, and adhesionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 11 2007David O. Meredith Abstract Stainless Steel (SS), titanium (cpTi), and Ti-6Al-7Nb (TAN) are frequently used metals in fracture fixation, which contact not only bone, but also soft tissue. In previous soft tissue cytocompatibility studies, TAN was demonstrated to inhibit cell growth in its "standard" micro-roughened state. To elucidate a possible mechanism for this inhibition, cell area, shape, adhesion, and cytoskeletal integrity was studied. Only minor changes in spreading were observed for cells on electropolished SS, cpTi, and TAN. Cells on "standard" cpTi were similarly spread in comparison with electropolished cpTi and TAN, although the topography influenced the cell periphery and also resulted in lower numbers and shorter length of focal adhesions. On "standard" microrough TAN, cell spreading was significantly lower than all other surfaces, and cell morphology differed by being more elongated. In addition, focal adhesion numbers and mean length were significantly lower on standard TAN than on all other surfaces, with 80% of the measured adhesions below a 2-µm threshold. Focal adhesion site location and maturation and microtubule integrity were compromised by the presence of protruding ,-phase microspikes found solely on the surface of standard TAN. This led us to propose that the impairment of focal adhesion numbers, maturation (length), and cell spreading to a possibly sufficient threshold observed on standard TAN blocks cell cycle progress and eventually cell growth on the surface. We believe, as demonstrated with standard cpTi and TAN, that a difference in surface morphology is influential for controlling cell behavior on implant surfaces. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1523,1533, 2007 [source] UVR8 in Arabidopsis thaliana regulates multiple aspects of cellular differentiation during leaf development in response to ultraviolet B radiationNEW PHYTOLOGIST, Issue 2 2009Jason J. Wargent Summary ,,Responses specific to ultraviolet B (UV-B) wavelengths are still poorly understood, both in terms of initial signalling and effects on morphogenesis. Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is the only known UV-B specific signalling component, but the role of UVR8 in leaf morphogenesis is unknown. ,,The regulatory effects of UVR8 on leaf morphogenesis at a range of supplementary UV-B doses were characterized, revealing both UVR8-dependent and independent responses to UV irradiation. ,,Inhibition of epidermal cell division in response to UV-B is largely independent of UVR8. However, overall leaf growth under UV-B irradiation in wild-type plants is enhanced compared with a uvr8 mutant because of a UVR8-dependent compensatory increase of cell area in wild-type plants. UVR8 was also required for the regulation of endopolyploidy in response to UV-B, and the uvr8 mutant also has a lower density of stomata than the wild type in the presence of UV-B, indicating that UVR8 has a regulatory role in other developmental events. ,,Our findings show that, in addition to regulating UV-protective gene expression responses, UVR8 is involved in controlling aspects of leaf growth and morphogenesis. This work extends our understanding of how UV-B response is orchestrated at the whole-plant level. [source] Leaf expansion in Phaseolus: transient auxin-induced growth increasePHYSIOLOGIA PLANTARUM, Issue 4 2007Christopher P. Keller Control of leaf expansion by auxin is not well understood. Evidence from short-term exogenous applications and from treatment of excised tissues suggests auxin positively influences growth. Manipulations of endogenous leaf auxin content, however, suggest that long-term auxin suppresses leaf expansion. This study attempts to clarify the growth effects of auxin on unifoliate (primary) leaves of the common bean (Phaseolus vulgaris) by reexamining the response to auxin treatment of both excised leaf strips and attached leaves. Leaf strips, incubated in culture conditions that promoted steady elongation for up to 48 h, treated with 10 ,M,-naphthalene acetic acid (NAA) responded with an initial surge of elongation growth complete within 10 h, followed by insensitivity. A range of NAA concentrations from 0.1 to 300 ,M induced increased strip elongation after 24 and 48 h. Increased elongation and epinastic curvature of leaf strips was found specific to active auxins. Expanding attached unifoliates treated once with aqueous auxin NAA at 1.0 mM showed both an initial surge in growth lasting 4,6 h followed by growth inhibition sustained at least as long as 24 h post-treatment. Auxin-induced inhibition of leaf expansion was associated with smaller epidermal cell area. Together, the results suggest increasing leaf auxin first increases growth and then slows growth through inhibition of cell expansion. Excised leaf strips retain only the initial increased growth response to auxin and not the subsequent growth inhibition, either as a consequence of wounding or as a consequence of isolation from the plant. [source] Effects of ultra-high flux and intensity distribution in multi-junction solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 4 2006Eugene A. Katz Abstract We report results of high-flux experiments on tandem solar cells, with a real-sun probe predicated on mini-dish fiber-optic concentrators. Experimental results and their interpretation focus on: (a) a striking insensitivity of cell efficiency to flux map; (b) the predictability of the flux values at which cell efficiency peaks; and (c) performance of the same cell architecture at markedly smaller cell area. Copyright © 2006 John Wiley & Sons, Ltd. [source] Intestinal Villus Histological Alterations in Piglets fed Dietary Charcoal Powder Including Wood Vinegar Compound LiquidANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2004A. Mekbungwan Summary To investigate the effects of dietary charcoal powder including wood vinegar compound liquid (CWVC, 4 : 1) on intestinal villus histology, piglets were fed 0, 1, 3 and 5% dietary CWVC diets for 30 days. Feed intake and body weight gain were measured during the experimental period. At the end of the experiments, intestinal villus height, epithelial cell area and cell mitosis were examined using light microscopy (LM), and the duodenal villus tip surface was observed using scanning electron microscopy (SEM). Feed efficiency tended to be improved in the CWVC group. The 3% CWVC group showed the highest value, followed by 1% CWVC group of most LM parameters in most intestinal parts, but the 5% CWVC group showed the almost similar value compared with the control. In addition, on the duodenal villus tip surface, the 3% CWVC group showed a clearer cell outline, larger cells and cells protuberated further into the lumen than those of the 1% CWVC group. However, the 5% CWVC group showed faint SEM features than the 1% CWVC group. The present trend of improved feed efficiency after feedings of dietary CWVC demonstrates that the CWVC could be incorporated into piglet diets up to 3% level, and that the CWVC might activate intestinal functions both at villus and cellular levels. [source] Generation of mature dendritic cells fully capable of T helper type 1 polarization using OK-432 combined with prostaglandin E2CANCER SCIENCE, Issue 12 2003Marimo Sato Dendritic cell (DC) administration appears to be a very promising approach for the immunotherapy of cancer. The results of clinical studies have suggested that the nature and the magnitude of antitumor immune responses are critically affected by DC functions, including production of T helper type 1 (Th1)-inducing cytokines, activation of T cell subsets and natural killer (NK) cells, and migration from peripheral tissues to the T cell area of the draining lymph nodes. Administration of immature DCs could fail to fully stimulate antigen-specific immune responses and might induce tolerance under some conditions. In this study, we developed a method to obtain fully mature DCs, and we compared in detail the DCs thus obtained with those obtained using a maturation stimulus termed monocyte-derived medium (MCM)-mimic, which is a mixture of recombinant cytokines and prostaglandin E2 (PGE2) mimicking the components of monocyte-conditioned medium. Using DCs derived from monocytes of advanced cancer patients in this study, we found that DCs stimulated with OK-432 alone showed phenotypes similar to those of mature DCs induced using MCM-mimic, though with better secretion of IL-6 and IL-12. However, these DCs were found to have poor migratory capacity associated with the marginal expression of CCR7. When OK-432 was combined with PGE2, the CCR7 expression and migratory capacity of DCs were significantly improved without impairing other immuno-stimulatory functions. These results suggest that stimulation with the combination of OK-432 and PGE2 could be applicable as an alternative to MCM-mimic in clinical trials which require fully matured DCs to induce Th1-type immune responses against tumor cells even in patients with advanced cancer. [source] CD4+ T cells from mice with intestinal immediate-type hypersensitivity induce airway hyperreactivityCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2007C. Ozdemir Summary Background A subset of food-allergic patients does not only respond clinically with symptoms in the gastro-intestinal tract but also with asthmatic reactions. Objective The aim of this study was to analyse whether CD4+ T cells from mice with intestinal immediate-hypersensitivity reactions to food allergen are involved in the development of experimental asthma. Methods BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA), followed by repeated intra-gastric (i.g.) OVA challenges. Control animals were either sham-sensitized or sham-challenged with phosphate-buffered saline (PBS). Duodenum, jejunum, ileum and colon were histologically examined. CD4+ T cells from mesenteric lymph nodes were transferred from various donor groups into recipient mice that received either OVA or PBS aerosol challenges. Recipients were analysed by measurements of lung function using head-out body-plethysmography and examination of broncho-alveolar lavage and lung histology. Results The highest levels of OVA-specific IgE antibody levels were detected in OVA-sensitized and OVA-challenged mice. Throughout the lower intestinal tract, a marked infiltration with eosinophils was observed, and goblet cell numbers as well as goblet cell area were significantly increased. The villus/crypt ratio was decreased compared with controls. The transfer of CD4+ T cells from mesenteric lymph nodes of OVA-sensitized and OVA-challenged mice triggered airway hyperreactivity and eosinophilic airway inflammation in recipients aerosol challenged with OVA, but not with PBS. Conclusion We conclude that CD4+ T cells from mesenteric lymph nodes of mice with allergen-induced immediate-type hypersensitivity reactions in the gut are able to transfer the phenotype of experimental asthma. [source] Could the coefficient of variation (COV) of the corneal endothelium be overestimated when a centre-dot method is used?CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 1 2008Michael J Doughty PhD Background:, Little has been published on the reliability of estimates of the coefficient of variation (COV) in cell area for human corneal endothelia. The present study compares two methods. Methods:, A non-contact specular micrograph (Topcon SP-2000P) was obtained from the central region of the corneal endothelium of 20 healthy myopic white European subjects, aged from 32 to 53 years, half of whom were successful long-term soft contact lens wearers. The captured image file was either assessed using a machine-based algorithm, in which 25 cells in the middle of the image were marked and their areas reported (designated as ,centre-dot' method) or by a manual method, by which all the cells in the image were outlined on very high magnification prints of the endothelia and the cell areas measured by a manual digitiser in stream mode. The average cell area was used to calculate the endothelial cell density (ECD), while the COV was calculated from the standard deviation (SD) of the cell area measures. Results:, Identical mean cell area values were found (392 µm2) with the two methods, a marginally higher ECD estimate (2,594 versus 2,569) with the centre-dot method (p = NS) but a much higher COV with the centre-dot method (43.8 versus 29.0 per cent). This highly statistically significant difference in COV (p < 0.001) was seen in both contact lens wearers and non-contact lens wearers. A Bland-Altman analysis reveals a bias in the centre-dot method, especially for the COV estimates, that appears to be linked to erroneous definition of a single large cell domain on any individual image. Conclusions:, A centre-dot method can be reliably used to generate useful data on cell area and ECD but it should be used cautiously for estimates of polymegethism (COV). [source] The distribution of Voronoi cells generated by Southern California earthquake epicentersENVIRONMETRICS, Issue 2 2009Frederic Paik Schoenberg Abstract The cells of Voronoi diagrams generated by epicentral locations of Southern California earthquakes are inspected. The tapered Pareto distribution is shown to fit quite well to the distribution of cell areas and perimeters. This same distribution, which has been used to model the distribution of seismic moments, is also a close approximation to the empirical distributions of times and distances between successive earthquakes for the same catalog of Southern California events. Verification is performed using a variety of different windows and sub-sampling procedures in order to confirm that the results are not an artifact of the particular parameters of the selected earthquake catalog. Copyright © 2008 John Wiley & Sons, Ltd. [source] Expression of the NKG2D ligand UL16 binding protein-1 (ULBP-1) on dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2006David Schrama Abstract Innate and adaptive immunity have not evolved separately. In this regard, the NKG2D molecule first identified on NK cells and classified as an activating NK cell receptor is also an important receptor for CD8+ T,cells. Functional analyses of human NKG2D and its ligands, i.e. UL16 binding proteins (ULBP) and MHC class I chain-related (MIC), have so far focused on immune cell-target cell situations because of the expression of NKG2D ligands on infected, stressed or transformed cells. Here, however, we address a possible function of NKG2D/ULBP-1 during the initiation of T cell responses. ULBP-1 can be detected on mature dendritic cells both in situ in the T cell areas of lymph nodes as well as in vitro after artificial maturation. FCM analysis further demonstrated that although NKG2D is expressed to some degree on all analyzed T cell subsets from peripheral blood, in vitro stimulation of T cells results in up-regulation of NKG2D on proliferating T cells. Using the sentinel lymph nodes of primary melanoma as a model for induction of defined T cell responses in vivo, we were able to demonstrate the expression of NKG2D on melanoma-associated antigen-specific T cells. Thus, our results suggest a role for NGK2D-ULBP-1 in the induction or reactivation of T cell responses. [source] Efficiency Enhancement in Organic Photovoltaic Cells: Consequences of Optimizing Series ResistanceADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Jonathan D. Servaites Abstract Here, means to enhance power conversion efficiency (PCE or ,) in bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells by optimizing the series resistance (Rs),also known as the cell internal resistance,are studied. It is shown that current state-of-the-art BHJ OPVs are approaching the limit for which efficiency can be improved via Rs reduction alone. This evaluation addresses OPVs based on a poly(3-hexylthiophene):6,6-phenyl C61 -butyric acid methyl ester (P3HT:PCBM) active layer, as well as future high-efficiency OPVs (,,>,10%). A diode-based modeling approach is used to assess changes in Rs. Given that typical published P3HT:PCBM test cells have relatively small areas (,0.1,cm2), the analysis is extended to consider efficiency losses for larger area cells and shows that the transparent anode conductivity is then the dominant materials parameter affecting Rs efficiency losses. A model is developed that uses cell sizes and anode conductivities to predict current,voltage response as a function of resistive losses. The results show that the losses due to Rs remain minimal until relatively large cell areas (>0.1,cm2) are employed. Finally, Rs effects on a projected high-efficiency OPV scenario are assessed, based on the goal of cell efficiencies >10%. Here, Rs optimization effects remain modest; however, there are now more pronounced losses due to cell size, and it is shown how these losses can be mitigated by using higher conductivity anodes. [source] Impulse conduction and gap junctional remodelling by endothelin-1 in cultured neonatal rat ventricular myocytesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2009Y. Reisner Abstract Endothelin-1 (ET-1) is an important contributor to ventricular hypertrophy and failure, which are associated with arrhythmogenesis and sudden death. To elucidate the mechanism(s) underlying the arrhythmogenic effects of ET-1 we tested the hypothesis that long-term (24 hrs) exposure to ET-1 impairs impulse conduction in cultures of neonatal rat ventricular myocytes (NRVM). NRVM were seeded on micro-electrode-arrays (MEAs, Multi Channel Systems, Reutlingen, Germany) and exposed to 50 nM ET-1 for 24 hrs. Hypertrophy was assessed by morphological and molecular methods. Consecutive recordings of paced activation times from the same cultures were conducted at baseline and after 3, 6 and 24 hrs, and activation maps for each time period constructed. Gap junctional Cx43 expression was assessed using Western blot and confocal microscopy of immunofluorescence staining using anti-Cx43 antibodies. ET-1 caused hypertrophy as indicated by a 70% increase in mRNA for atrial natriuretic peptide (P < 0.05), and increased cell areas (P < 0.05) compared to control. ET-1 also caused a time-dependent decrease in conduction velocity that was evident after 3 hrs of exposure to ET-1, and was augmented at 24 hrs, compared to controls (P < 0.01). ET-1 increased total Cx43 protein by ,40% (P < 0.05) without affecting non- phosphorylated Cx43 (NP-Cx43) protein expression. Quantitative confocal microscopy showed a ,30% decrease in the Cx43 immunofluorescence per field in the ET-1 group (P < 0.05) and a reduced field stain intensity (P < 0.05), compared to controls. ET-1-induced hypertrophy was accompanied by reduction in conduction velocity and gap junctional remodelling. The reduction in conduction velocity may play a role in ET-1 induced susceptibility to arrhythmogenesis. [source] Expression patterns of hair and epithelial keratins and transcription factors HOXC13, LEF1, and ,-catenin in a malignant pilomatricoma: a histological and immunohistochemical studyJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2006Bernard Cribier Background:, We have previously shown that benign pilomatricomas not only maintain the sequential expression of the hair matrix and precortex keratins hHa5 and hHa1 of normal hair follicles in their transitional cell compartment, but also preserve the association of hHa5 expression with that of its regulatory homeoprotein HOXC13 in the lower transitional cell compartment. In contrast, hHa1 expression in the upper transitional cell compartment is uncoupled from the nuclear co-expression of the LEF1/,-catenin complex seen in normal hair follicles (Cribier et al., J Invest Dermatol 2004; 122: 1078). Methods:, Formalin-fixed paraffin sections of the tumor were examined using a panel of mono- and polyclonal hair and epithelial keratin antibodies as well as antibodies against HOXC13, LEF1, and ,-catenin. Results:, Morphologically, the malignant pilomatricoma investigated here clearly deviated from the described major tumor type by a large number of differently sized parakeratotic squamoid whorls emerging within the mass of basaloid cells and surrounded by cells remembering transitional cells, but only rarely containing shadow cells and signs of calcification. We show that hHa5/HOXC13 co-expression was maintained in transitional cell areas, in which hHa1 expression was much stronger than in benign pilomatricomas, but again uncoupled from concomitant nuclear LEF1/,-catenin expression. Surprisingly, however, and in clear contrast to benign pilomatricomas, these transitional cells co-expressed the epithelial keratins K5, K14, and K17, with the latter being as strongly expressed as hHa1, both also staining the entire inner mass of the parakeratotic whorls. Conclusions:, Although the malignant pilomatricoma investigated here was distinctive in that it contained a multitude of parakeratinizing whorls and no signs of calcification, it shared both hHa5/HOXC13 co-expression and disrupted hHa1/,-catenin,LEF1 expression in its transitional cell compartment around the whorls with benign pilomatricomas. However, in clear contrast to the latter, transitional cells of the malignant tumor also strongly expressed the epithelial keratins K5, K14, and K17. We speculate that the observed dominance of the epithelial differentiation pathway over the competing conventional shadow cell differentiation pathway may prevent massive calcification of the tumor. [source] Origin and evolution of somatic cell testicular tumours in transgenic mice,THE JOURNAL OF PATHOLOGY, Issue 4 2010Silvina Quintana Abstract Transgenic mice bearing a construct in which the expression of the SV40 oncogene is directed by the AMH promoter (AT mice) develop testicular tumours in adult life. We aimed to study early steps of tumour development and characterize tumours at different ages by histological, morphometric, and immunohistochemical techniques. One- to 3-month-old AT mice depicted multifocal Leydig cell hyperplasia. The testicular volume occupied by interstitial tissue was significantly higher in 3-month-old AT mice in comparison with littermate controls. Between 5 1/2 and 7 months, microscopic interstitial tumours developed that progressively evolved to form large confluent areas of high mitotic index in 7- to 14-month-old AT mice. Tumour cells had the characteristics and histoarchitecture of Leydig cells, or formed solid cord-like structures reminiscent of those seen in Sertoli cell tumours. Hyperplastic areas and tumours diffusely expressed 3,-hydroxysteroid dehydrogenase (3,-HSD) in Leydig cell areas. AMH expression was negative in Leydig cell conglomerates and tumours and variable in cord-like tumours. The SV40 T antigen and markers of cell proliferation (PCNA) were intensely positive in hyperplastic cells and tumours. Control mice of similar ages showed neither hyperplasia nor tumours, and SV40 T expression was always negative. In conclusion, transgenic mice develop large testicular tumours that are preceded by interstitial hyperplasia and microtumours. The histological and immunohistochemical phenotype of tumours (Leydig and Sertoli cell differentiation, positive 3,-HSD, and variable AMH) suggests a mixed differentiation of somatic cells of the specialized gonadal stroma. The finding that an oncogene directed by a promoter specifically active in fetal Sertoli cells has given rise to testicular tumours of mixed differentiation is compatible with a common origin of Leydig and Sertoli cells from the specific stroma of the gonadal ridge, as supported by double labelling experiments in fetal mice showing co-localization of the transgene with Sertoli and Leydig cell markers. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] AMACR is not applicable as a diagnostic tool in hepatocellular carcinomaAPMIS, Issue 2 2010GRO LINNO WILLEMOE Willemoe GL, Vainer B. AMACR is not applicable as a diagnostic tool in hepatocellular carcinoma. APMIS 2010; 118: 85,90. ,-methylacyl coenzyme A racemase (AMACR or P504S) is a mitochondrial and peroxisomal protein present in a variety of human cells. Demonstration of increased expression is used diagnostically in prostatic adenocarcinoma. AMACR is also produced by normal hepatocytes and it has been postulated that the demonstration of AMACR expression or its pattern of distribution is useful in the diagnosis of hepatocellular carcinoma (HCC) (Jiang et al., Hum Pathol 2003;34, Guzman et al., Appl Immunohistochem Mol Morphol 2006;14, Li et al., J Exp Clin Cancer Res 2008;27). The aim of the present study was to evaluate whether immunohistochemical staining for AMACR can be used in a routine histopathologic setting. Immunohistochemical staining for AMACR was performed on paraffin-embedded tissue from livers resected for HCC during 1980,2006 at Rigshospitalet, Copenhagen, Denmark (n = 44). Tumor sections as well as surrounding non-neoplastic tissues were studied. In both tumor and non-tumor tissues, intracellular localization and staining pattern were assessed and the staining intensity of AMACR was graded. The fraction of stained tumor cells was not significantly different from that of stained non-tumor cells in the same patients (p = 0.97). A significantly lower staining intensity was observed in clear cell areas (p = 0.005), but the AMACR expression did not correlate with the HCC type and could not distinguish neoplastic from non-neoplastic liver cells. AMACR is not applicable as a tool in the histopathologic diagnosis of HCC. [source] | |||||||||||||||||||