74 resultados para 336.3435


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Cultured primary epithelial cells are used to examine inflammation in cystic fibrosis (CF). We describe a new human model system using cultured nasal brushings. Nasal brushings were obtained from 16 F508del homozygous patients and 11 healthy controls. Cells were resuspended in airway epithelial growth medium and seeded onto collagen-coated flasks and membranes for use in patch-clamp, ion transport, and mediator release assays. Viable cultures were obtained with a 75% success rate from subjects with CF and 100% from control subjects. Amiloride-sensitive epithelial Na channel current of similar size was present in both cell types while forskolin-activated CF transmembrane conductance regulator current was lacking in CF cells. In Ussing chambers, cells from CF patients responded to UTP but not to forskolin. Spontaneous and cytomix-stimulated IL-8 release was similar (stimulated 29,448 ± 9,025 pg/ml; control 16,336 ± 3,308 pg/ml CF; means ± SE). Thus nasal epithelial cells from patients with CF can be grown from nasal brushings and used in electrophysiological and mediator release studies in CF research.

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Specific survival signals derived from extracellular matrix (ECM) and growth factors are required for mammary epithelial cell survival. We have previously demonstrated that inhibition of ECM-induced ERK1/2 MAPK pathway with PD98059 leads to apoptosis in primary mouse mammary epithelial cells. In this study, we have further investigated MAPK signal transduction in cell survival of these cells cultured on a laminin rich reconstituted basement membrane. ERK1/2 phosphorylation is activated in the absence of insulin by cell-cell substratum interactions that cause ligand-independent EGFR transactivation. Intact EGFR signal transduction is required for ECM determined cell survival as the EGFR pathway inhibitor, AG1478, induces apoptosis of these cultures. Rescue of AG1478 or PD98059 treated cultures by PTPase inhibition with vanadate restores cellular phospho-ERK1/2 levels and prevents apoptosis. These results emphasize that ERK1/2 phosphorylation and inhibition of PTPase activity are necessary for PMMEC cell survival.

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Aim: Intrauterine, early life and maternal exposures may have important consequences for cancer development in later life. The aim of this study was to examine perinatal and birth characteristics with respect to Cutaneous malignant melanoma (CMM) risk. Methods: The Northern Ireland Child Health System database was used to examine gestational age adjusted birth weight, infant feeding practices, parental age and socioeconomic factors at birth in relation to CMM risk amongst 447,663 infants delivered between January 1971 and December 1986. Follow-up of histologically verified CMM cases was undertaken from the beginning of 1993 to 31st December 2007. Multivariable adjusted unconditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) of CMM risk. Results: A total of 276 CMM cases and 440,336 controls contributed to the final analysis. In reference to normal (gestational age-adjusted) weight babies, those heaviest at birth were twice as likely to develop CMM OR 2.4 (95% CI 1.1-5.1). Inverse associations with CMM risk were observed with younger (

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Porous layered hybrid materials have been prepared by the reaction of organo-bisphosphonate ligands, 4-(4'-phosphonophenoxy)phenylphosphonic, 4,4'-biphenylenbisphosphonic and phenylphosphonic acids, with metal(IV) cations (Zr and Sn). Crystalline Zr(IV) and Sn(IV) layered bisphosphonates were also prepared, which were non-porous. The amorphous M(IV) bisphosphonates showed variable compositions and textural properties ranging from mainly mesoporous to highly microporous solids with BET surface areas varying from 300 to 480 m(2) g(-1), micropore volumes ranging 0.10-0.20 cm(3)/g, and narrow porous size distributions for some materials. N-2 isotherms suggest that Sn(IV) derivatives show a comparatively higher micropore contribution than the Zr(IV) analogous at least for the ether-bisphosphonate hybrids. Sn(IV) bisphosphonates exhibit high microporosities without the need of using harmful DMSO as solvent. If ether-bisphosphonic acid is partially replaced by less expensive phenylphosphonic ligand, porous products are also obtained. P-31 and F-17 MAS NMR and XPS data revealed the presence of hydrogen-phosphonate groups and small (F-, Cl- and OH-) anions, which act as spacer ligands within the inorganic layers, in these hybrid materials. The complexity of the inorganic layers is higher for the Sn(IV) bisphosphonates likely due to the larger amount of small bridging anions including fluorides. It is suggested that the presence of these small inorganic ligands may be a key factor influencing both, the interaction of the inorganic layer with the bisphosphonate groups, which bridge the inorganic layers, and the generation of internal voids within a given inorganic layer. Preliminary studies of gases adsorption (H-2 and NO) have been carried out for selected Sn(IV) bisphosphonates. The H-2 adsorption capacity at 77 K and 1 bar was low, 0.26 wt%, but the NO adsorption capacity at similar to 1 bar and 298 K was relatively high, 4.2 wt%. Moreover, the hysteresis in the NO isotherms is indicative of partial strong irreversible adsorption of NO. (C) 2008 Elsevier Inc. All rights reserved.

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The aim of this study was to compare time-domain waveform analysis of second-trimester uterine artery Doppler using the resistance index (RI) with waveform analysis using a mathematical tool known as wavelet transform for the prediction of pre-eclampsia (PE). This was a retrospective, nested case-cohort study of 336 women, 37 of whom subsequently developed PE. Uterine artery Doppler waveforms were analysed using both RI and waveform analysis. The utility of these indices in screening for PE was then evaluated using receiver operating characteristic curves. There were significant differences in uterine artery RI between the PE women and those with normal pregnancy outcome. After wavelet analysis, significant difference in the mean amplitude in wavelet frequency band 4 was noted between the 2 groups. The sensitivity for both Doppler RI and frequency band 4 for the detection of PE at a 10% false-positive rate was 45%. This small study demonstrates the application of wavelet transform analysis of uterine artery Doppler waveforms in screening for PE. Further prospective studies are needed in order to clearly define if this analytical approach to waveform analysis may have the potential to improve the detection of PE by uterine artery Doppler screening.

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Aim-To develop an expert system model for the diagnosis of fine needle aspiration cytology (FNAC) of the breast.

Methods-Knowledge and uncertainty were represented in the form of a Bayesian belief network which permitted the combination of diagnostic evidence in a cumulative manner and provided a final probability for the possible diagnostic outcomes. The network comprised 10 cytological features (evidence nodes), each independently linked to the diagnosis (decision node) by a conditional probability matrix. The system was designed to be interactive in that the cytopathologist entered evidence into the network in the form of likelihood ratios for the outcomes at each evidence node.

Results-The efficiency of the network was tested on a series of 40 breast FNAC specimens. The highest diagnostic probability provided by the network agreed with the cytopathologists' diagnosis in 100% of cases for the assessment of discrete, benign, and malignant aspirates. A typical probably benign cases were given probabilities in favour of a benign diagnosis. Suspicious cases tended to have similar probabilities for both diagnostic outcomes and so, correctly, could not be assigned as benign or malignant. A closer examination of cumulative belief graphs for the diagnostic sequence of each case provided insight into the diagnostic process, and quantitative data which improved the identification of suspicious cases.

Conclusion-The further development of such a system will have three important roles in breast cytodiagnosis: (1) to aid the cytologist in making a more consistent and objective diagnosis; (2) to provide a teaching tool on breast cytological diagnosis for the non-expert; and (3) it is the first stage in the development of a system capable of automated diagnosis through the use of expert system machine vision.

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Aim: To study the long-term outcome of deep sclerectomy in patients with open angle glaucoma. Methods: Prospective consecutive series of 43 eyes (38 patients) with medically uncontrolled open-angle glaucoma undergoing deep sclerectomy. All patients underwent clinical assessment before and after surgery at day 7 and at months 1, 3, 6, 12, 18, 24, 36. Surgical success was considered if the patient's intraocular pressure (IOP)>22 mmHg and the IOP was lowered by more than 20% without the use of any medication. Kaplan-Meier survival curves were used to evaluate the success rate. Results: The mean follow-up time was 28.1±8.2 months. Mean IOP decreased significantly from a preoperative value of 24.6±5.5 mmHg to a postoperative value of 18.5±4.6 mmHg at 36 months (P>0.001). Microperforation of TDM occurred in three cases (7.0%) and ciliary body prolapse in one case (2.3%) but did not prevent completion of the operation. Postoperatively, hyphaema was detected in one case and shallow anterior chamber in another case and both were treated conservatively. Bleb encapsulation with elevation of IOP occurred in two cases (4.7%) and was treated with 5-fluorouracil subconjunctival injection. Goniopuncture with neodymium : YAG laser was performed in two cases (4.7%). There were no other late complications with the exception of failure of the operation. On the life-table analysis the success rate at 12, 24, and 30 months were 61.4, 36.6, and 18.9%, respectively. Conclusion: Deep sclerectomy reduced the IOP temporarily while minimising the risk of postoperative complications commonly encountered with standard trabeculectomy. However, after long-term follow-up surgery failed to maintain a low IOP. © 2006 Nature Publishing Group. All rights reserved.

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This paper introduces the paired comparison model as a suitable approach for the analysis of partially ranked data. For example, the Inglehart index, collected in international social surveys to examine shifts in post-materialistic values, generates such data on a set of attitude items. However, current analysis methods have failed to account for the complex shifts in individual item values, or to incorporate subject covariates. The paired comparison model is thus developed to allow for covariate subject effects at the individual level, and a reparameterization allows the inclusion of smooth non-linear effects of continuous covariates. The Inglehart index collected in the 1993 International Social Science Programme survey is analysed, and complex non-linear changes of item values with age, level of education and religion are identified. The model proposed provides a powerful tool for social scientists.

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A systematic review was conducted of studies evaluating the effects of interventions aimed at reducing ethnic prejudice and discrimination in young children. Articles published between 1980 and 2010 and including children of 8 years and under were identified, harvested, and assessed for quality, both for the exposure/program as well as for the evaluation. In total, 32 studies (14 contact and 18 media or instruction) yielded 62 effects on attitudes and 59 effects on peer relations. An overall count of the positive (40%), non-significant (50%), and negative effects (10%) indicate a mixed picture. Overall, more attitude effects (55%) than peer relations effects (25%) were positive, and media/instruction (47%) was more successful than contact (36%). Most of the effects were observed with children from a majority ethnicity: 67% of the attitude effects were positive, and media/instruction and contact were equally effective at delivering these. Few differences were found as a function of the quality of the exposure and evaluation, but differences were found depending on the context of exposure (naturally occurring or experimental manipulation) and research design (random assignment or self-selection). In conclusion, the findings were more mixed than expected, though sufficiently strong studies exist to provide lessons for future research.


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What influences how well-prepared student teachers feel towards working in schools upon completion of their initial teacher preparation (ITP)? In order to investigate this question, we used a path analysis using data from a longitudinal study investigating the experiences of trainee and early career phase teachers in England. The data were generated via self-complete questionnaires and follow-up telephone interviews with 1,322 trainees. Those on undergraduate or school-based programmes felt better prepared to work as teachers than one-year postgraduate trainees, perhaps because the former give higher ratings of the quality of assessment of, and feedback received on, teaching practice, and because of the clarity of theory-practice links in programmes. Across different kinds of ITP programme, good relationships with school-based mentors significantly boosted trainees' confidence that their ITP had effectively prepared them for teaching. Trainees' motives for entering the profession and their initial concerns about and expectations of ITP also affected their perceptions of its effectiveness, by shaping the way they experienced aspects of their courses. Implications of these findings for policy and practice in teacher preparation are discussed. © 2011 Blackwell Publishing Ltd.

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AC magnetic heating of superparamagnetic Co and Fe nanoparticles for application in hyperthermia was measured to find a size of nanoparticles that would result in an optimal heating for given amplitude and frequency of ac externally applied magnetic field. To measure it, a custom-made power supply connected to a 20-turn insulated copper coil in the shape of a spiral solenoid cooled with water was used. A fiber-optic temperature sensor has been used to measure the temperature with an accuracy of 0.0001 K. The magnetic field with magnitude of 20.6 µT and a frequency of oscillation equal to 348 kHz was generated inside the coil to heat magnetic nanoparticles. The maximum specific power loss or the highest heating rate for Co magnetic nanoparticles was achieved for nanoparticles of 8.2 nm in diameter. The maximum heating rate for coated Fe was found for nanoparticles with diameter of 18.61 nm. © (2013) Trans Tech Publications, Switzerland.

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Purpose: Despite the use of 5-fluorouracil (5-FU)–based adjuvant treatments, a large proportion of patients with high-risk stage II/III colorectal cancer will relapse. Thus, novel therapeutic strategies are needed for early-stage colorectal cancer. Residual micrometastatic disease from the primary tumor is a major cause of patient relapse.

Experimental Design: To model colorectal cancer tumor cell invasion/metastasis, we have generated invasive (KRASMT/KRASWT/+chr3/p53-null) colorectal cancer cell subpopulations. Receptor tyrosine kinase (RTK) screens were used to identify novel proteins that underpin the migratory/invasive phenotype. Migration/invasion was assessed using the XCELLigence system. Tumors from patients with early-stage colorectal cancer (N = 336) were examined for AXL expression.

Results: Invasive colorectal cancer cell subpopulations showed a transition from an epithelial-to-mesenchymal like phenotype with significant increases in migration, invasion, colony-forming ability, and an attenuation of EGF receptor (EGFR)/HER2 autocrine signaling. RTK arrays showed significant increases in AXL levels in all invasive sublines. Importantly, 5-FU treatment resulted in significantly increased migration and invasion, and targeting AXL using pharmacologic inhibition or RNA interference (RNAi) approaches suppressed basal and 5-FU–induced migration and invasion. Significantly, high AXL mRNA and protein expression were found to be associated with poor overall survival in early-stage colorectal cancer tissues.

Conclusions: We have identified AXL as a poor prognostic marker and important mediator of cell migration/invasiveness in colorectal cancer. These findings provide support for the further investigation of AXL as a novel prognostic biomarker and therapeutic target in colorectal cancer, in particular in the adjuvant disease in which EGFR/VEGF–targeted therapies have failed.

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Directional Modulation (DM) is a recently proposed technique for securing wireless communication. In this paper we point out that modulation-directionality is a consequence of varying the beamforming network, either in baseband or in the RF stage, at the information rate In order to formalize and extend on previous analysis and synthesis methods a new theoretical treatment using vector representations of directional modulation (DM) systems is introduced and used to obtain the necessary and sufficient con