82 resultados para glandular wing
Resumo:
Disruption of glandular architecture associates with poor clinical outcome in high-grade colorectal cancer (CRC). Phosphatase and tensin homolog deleted on chromosome ten (PTEN) regulates morphogenic growth of benign MDCK (Madin Darby Canine Kidney) cells through effects on the Rho-like GTPase cdc42 (cell division cycle 42). This study investigates PTEN-dependent morphogenesis in a CRC model. Stable short hairpin RNA knockdown of PTEN in Caco-2 cells influenced expression or localization of cdc42 guanine nucleotide exchange factors and inhibited cdc42 activation. Parental Caco-2 cells formed regular hollow gland-like structures (glands) with a single central lumen, in three-dimensional (3D) cultures. Conversely, PTEN-deficient Caco-2 ShPTEN cells formed irregular glands with multiple abnormal lumens as well as intra- and/or intercellular vacuoles evocative of the high-grade CRC phenotype. Effects of targeted treatment were investigated. Phosphatidinylinositol 3-kinase (PI3K) modulating treatment did not affect gland morphogenesis but did influence gland number, gland size and/or cell size within glands. As PTEN may be regulated by the nuclear receptor peroxisome proliferator-activated receptor-? (PPAR?), cultures were treated with the PPAR? ligand rosiglitazone. This treatment enhanced PTEN expression, cdc42 activation and rescued dysmorphogenesis by restoring single lumen formation in Caco-2 ShPTEN glands. Rosiglitazone effects on cdc42 activation and Caco-2 ShPTEN gland development were attenuated by cotreatment with GW9662, a PPAR? antagonist. Taken together, these studies show PTEN-cdc42 regulation of lumen formation in a 3D model of human CRC glandular morphogenesis. Treatment by the PPAR? ligand rosiglitazone, but not PI3K modulators, rescued colorectal glandular dysmorphogenesis of PTEN deficiency.
Resumo:
The brightest and most vivid colours in nature arise from the interaction of light with surfaces that exhibit periodic structure on the micro- and nanoscale. In the wings of butterflies, for example, a combination of multilayer interference, optical gratings, photonic crystals and other optical structures gives rise to complex colour mixing. Although the physics of structural colours is well understood, it remains a challenge to create artificial replicas of natural photonic structures(1-3). Here we use a combination of layer deposition techniques, including colloidal self-assembly, sputtering and atomic layer deposition, to fabricate photonic structures that mimic the colour mixing effect found on the wings of the Indonesian butterfly Papilio blumei. We also show that a conceptual variation to the natural structure leads to enhanced optical properties. Our approach offers improved efficiency, versatility and scalability compared with previous approaches(4-6).
Resumo:
Organotypic models may provide mechanistic insight into colorectal cancer (CRC) morphology. Three-dimensional (3D) colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN) coupling of cell division cycle 42 (cdc42) to atypical protein kinase C (aPKC). This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM) orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3) were ineffective. The isolated PTEN C2 domain (C2) accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na/H exchanger regulatory factor-1 (NHERF-1) in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.
Resumo:
Finite Element simulations and mechanical tests are undertaken to assess the impact of weld joint location on stiffened panel static strength. An upper wing cover panel, with a manufacturing process of welding multiple near-net-shape multi-stiffener extrusions with a final net-shape machining phase is investigated. The 7000 series aluminium alloy extrusions and skin bay longitudinal friction stir butt welds are examined. Geometric imperfections exhibit the greatest influence on panel collapse, thus for static strength design the selection of weld joint location should minimise imperfection generation. Moreover the analysis demonstrates limited impact on panel collapse strength when an optimised welding process is employed. © 2013 Elsevier Ltd. All rights reserved.
Resumo:
In the last five years the forces of organised right-wing extremism have made electoral advances across many states in contemporary Europe. Germany has not been immune and the extreme right party, the National Democratic Party of Germany won its first seat in the European Parliament since 1989. The recent successes of the extreme right pose issues for European society about tolerance and immigration policy, but this scene has also been associated with an upsurge in racially motivated political violence and acts of right-wing terrorism. Much of this violence is perpetrated by small neo-Nazi styled groups. This paper looks at the most notorious and recent of such groups to emerge in Germany, the National Socialist Underground. The paper explores the origins and personalities behind this terror cell, provides derails of its criminal activities and murder spree, and questions why it took so long for the authorities to identify the NSU.
Resumo:
The impact of buckling containment features on the stability of thin-gauge fuselage, metallic stiffened panels has previously been demonstrated. With the continuing developments in manufacturing technology, such as welding, extrusion, machining, and additive layer manufacture, understanding the benefits of additional panel design features on heavier applications, such as wing panels, is timely. This compression testing of thick-gauge panels with and without buckling containment features has been undertaken to verify buckling and collapse behaviors and validate sizing methods. The experimental results demonstrated individual panel mass savings on the order of 9%, and wing cover design studies demonstrated mass savings on the order of 4 to 13%, dependent on aircraft size and material choice.
Resumo:
High-cadence Halpha blue wing observations of a C9.6 solar flare obtained at Big Bear Solar Observatory using the Rapid Dual Imager are presented. Wavelet and time-distance methods were used to study oscillatory power along the ribbon, finding periods of 40 - 80 s during the impulsive phase of the flare. A parametric study found statistically significant intensity oscillations with amplitudes of 3% of the peak flare amplitude, periods of 69 s (14.5 mHz) and oscillation decay times of 500 s. These measured properties are consistent with the existence of flare-induced acoustic waves within the overlying loops.
Resumo:
In Northern Ireland of the mid-1990s, many were caught off-guard by the comet-like arrival of a previously unarticulated Ulster Scots identity, replete with its own folk traditions. The article exploits the author’s position as Traditional Arts Officer of the Arts Council of Northern Ireland from 1998 until 2003 to offer an auto-ethnographic reflection on the literature on cultural politics in Northern Ireland since the outbreak of the Troubles, informed by extensive fieldwork with arts administrators and with contemporary Ulster Scots musicians. The article gives a close reading and historical contextualisation of the Ulster-Scots musical revue On Eagle's Wing, which was developed during this period. The article uses the concept of "suture" articulated by Lacan and developed by Laclau, Mouffe, and Žižek to explain both the potential for Ulster Scots culture to enter political discourse out of a seeming vacuum and its subsequent difficulties, offering an original interpretation of the role of culture in the contemporary trajectory of Northern Ireland politics.
Resumo:
Purpose: To investigate the association of cardiovascular risk factors and inflammatory markers with neovascular age-related macular degeneration (AMD). Design: Cross-sectional case-control study. Participants: Of the 410 of the =65-year-old community sample invited to attend, 205 participated (50% response rate). Of the 215 clinic attendees who were invited to participate, 212 agreed to take part (98% response rate). A diagnosis of neovascular AMD in at least one eye was made in 193 clinic attendees and 2 of the community sample. Methods: Clinic and community participants underwent a detailed ophthalmic examination with fundus imaging, were interviewed for assessment of putative risk factors, and provided a blood sample. Analysis included levels of serum lipids, intercellular adhesion molecule 1 (ICAM), vascular cellular adhesion molecule (VCAM), and C-reactive protein (CRP). All participants were classified by fundus image grading on the basis of the eye with more severe AMD features. Main Outcome Measure: Neovascular AMD. Results: There were 195 participants with choroidal neovascularization in at least one eye, 97 nonneovascular AMD participants, and 115 controls (no drusen or pigmentary irregularities in either eye). In confounder-adjusted logistic regression, a history of cardiovascular disease was strongly associated with neovascular AMD (odds ratio [OR], 7.53; 95% confidence interval [CI], 2.78-20.41). Cigarette smoking (OR, 3.71; 95% CI, 1.25-11.06), being in the highest quartile of body mass index (OR, 3.82; 95% CI, 1.22-12.01), stage 2 hypertension (OR, 3.21; 95% CI, 1.14-8.98), and being in the highest quartile of serum cholesterol (OR, 4.66; 95% CI, 1.35-16.13) were positively associated with neovascular AMD. There was no association between AMD status and serum CRP, ICAM, or VCAM. Conclusions: Our results suggest that cardiovascular disease plays an etiological role in the development of choroidal neovascularization in a proportion of older adults and highlight the importance of control of blood pressure and cholesterol, avoidance of smoking, and maintenance of a normal body weight. © 2008 American Academy of Ophthalmology.