219 research outputs found
Prospective study of intratumoral microvessel density, p53 expression and survival in colorectal cancer
Adjuvant treatment of patients with colorectal cancer is hampered by a lack of reliable prognostic factors in addition to the clinicopathological staging system. A poorly defined but considerable fraction of Astler–Coller stage B patients will experience tumour recurrence, and some of the stage C patients will probably survive for a prolonged time after surgery without adjuvant treatment. Assessing parameters related to tumour angiogenesis has provided valuable prognostic information in different tumour types. The formation of new microvessels is part of the malignant phenotype in the majority of tumours. Alterations in tumour-suppressor genes, such as the p53 gene, or oncogenes, such as the ras gene, have been found to be responsible for changing the local balance of pro- and antiangiogenic factors in favour of the former. In this prospective study, intratumoral microvessel density (IMD) was assessed by immunostaining tissue sections for CD31 and counting individual microvessels in selected and highly vascular regions in specimens of 145 colorectal cancer patients. p53 protein overexpression was semiquantitatively determined after immunohistochemistry. In both uni- and multivariate analysis, high IMD was significantly associated with shorter survival in the patients undergoing surgery with curative intent (Astler–Coller stages A–C). p53 added prognostic power to IMD, both in Astler–Coller stage B and stage C patients. An association between IMD and mode of metastasis was also noted. High IMD was strongly associated with the incidence of haematogenous metastasis during follow-up, but not with the presence of lymphogenic metastasis observed at surgery. This study confirms the results of previous retrospective analyses of IMD and survival in colorectal cancer and warrants a clinical validation by randomizing stage B tumour patients with high IMD and p53 overexpression between adjuvant treatment or not. © 1999 Cancer Research Campaig
Fructooligosacharides Reduce Pseudomonas aeruginosa PAO1 Pathogenicity through Distinct Mechanisms
Pseudomonas aeruginosa
is ubiquitously present in the environment and acts as an opportunistic pathogen on humans,
animals and plants. We report here the effects of the prebiotic polysaccharide inulin and its hydrolysed form FOS on this
bacterium. FOS was found to inhibit bacterial growth of strain PAO1, while inulin did not affect growth rate or yield in a
significant manner. Inulin stimulated biofilm formation, whereas a dramatic reduction of the biofilm formation was
observed in the presence of FOS. Similar opposing effects were observed for bacterial motility, where FOS inhibited the
swarming and twitching behaviour whereas inulin caused its stimulation. In co-cultures with eukaryotic cells (macrophages)
FOS and, to a lesser extent, inulin reduced the secretion of the inflammatory cytokines IL-6, IL-10 and TNF-
a
. Western blot
experiments indicated that the effects mediated by FOS in macrophages are associated with a decreased activation of the
NF-
k
B pathway. Since FOS and inulin stimulate pathway activation in the absence of bacteria, the FOS mediated effect is
likely to be of indirect nature, such as via a reduction of bacterial virulence. Further, this modulatory effect is observed also
with the highly virulent ptxS mutated strain. Co-culture experiments of P. aeruginosa with IEC18 eukaryotic cells showed
that FOS reduces the concentration of the major virulence factor, exotoxin A, suggesting that this is a possible mechanism
for the reduction of pathogenicity. The potential of these compounds as components of antibacterial and anti-inflammatory
cocktails is discussed.The authors acknowledge financial support from FEDER funds and Fondo Social Europeo through grants from the Spanish Ministry of Economy and Competitiveness (grants SAF2011-22922, SAF2011-22812) the Andalusian regional government Junta de Andalucía (grant CVI-7335) and the Centre of Networked
Biomedical Research on Hepatic and Digestive Diseases (CIBERehd) which is funded by the Carlos III Health Institute and the Ramón Areces Foundation, Spain
Anti-angiogenic therapy for cancer: Current progress, unresolved questions and future directions
Tumours require a vascular supply to grow and can achieve this via the expression of pro-angiogenic growth factors, including members of the vascular endothelial growth factor (VEGF) family of ligands. Since one or more of the VEGF ligand family is overexpressed in most solid cancers, there was great optimism that inhibition of the VEGF pathway would represent an effective anti-angiogenic therapy for most tumour types. Encouragingly, VEGF pathway targeted drugs such as bevacizumab, sunitinib and aflibercept have shown activity in certain settings. However, inhibition of VEGF signalling is not effective in all cancers, prompting the need to further understand how the vasculature can be effectively targeted in tumours. Here we present a succinct review of the progress with VEGF-targeted therapy and the unresolved questions that exist in the field: including its use in different disease stages (metastatic, adjuvant, neoadjuvant), interactions with chemotherapy, duration and scheduling of therapy, potential predictive biomarkers and proposed mechanisms of resistance, including paradoxical effects such as enhanced tumour aggressiveness. In terms of future directions, we discuss the need to delineate further the complexities of tumour vascularisation if we are to develop more effective and personalised anti-angiogenic therapies. © 2014 The Author(s)
Incidental findings in MRI of the paranasal sinuses in adults: a population-based study (HUNT MRI)
First measurement of the |t|-dependence of coherent J/ψ photonuclear production
The first measurement of the cross section for coherent J/ψ photoproduction as a function of |t|, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the ALICE detector in ultra-peripheral Pb–Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02TeV with the J/ψ produced in the central rapidity region |y|<0.8, which corresponds to the small Bjorken-x range (0.3−1.4)×10−3.
The measured |t|-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according to the leading-twist approximation, or gluon-saturation effects from the impact-parameter dependent Balitsky–Kovchegov equation. These new results are therefore a valid tool to constrain the relevant model parameters and to investigate the transverse gluonic structure at very low Bjorken-x.publishedVersio
Associations between social support, mental wellbeing, self-efficacy and technology use in first-time antenatal women: data from the BaBBLeS cohort study
Background: Information and communication technologies are used increasingly to facilitate social networks and support women during the perinatal period. This paper presents data on how technology use affects the association between women’s social support and, (i) mental wellbeing and, (ii) self-efficacy in the antenatal period. Methods: Data were collected as part of an ongoing study - the BaBBLeS study - exploring the effect of a pregnancy and maternity software application (app) on maternal wellbeing and self-efficacy. Between September 2016 and February 2017, we aimed to recruit first-time pregnant women at 12–16 gestation weeks in five maternity sites across England and asked them to complete questionnaires. Outcomes included maternal mental wellbeing (Warwick-Edinburgh Mental Wellbeing Scale), and antenatal self-efficacy (antenatal version of the Tool to Measure Parenting Self-Efficacy). Other variables assessed were perceived social support (Multidimensional Scale of Perceived Social Support), general technology use (adapted from Media and Technology Usage and Attitudes Scale). Potential confounders were age, ethnicity, education, socioeconomic deprivation, employment, relationship status and recruitment site. Linear regression models were developed to analyse the relationship between social support and the outcomes. Results: Participants (n = 492, median age = 28 years) were predominantly white British (64.6%). Half of them had a degree or higher degree (49.3%), most were married/living with a partner (83.6%) and employed (86.2%). Median (LQ-UQ) overall scores were 81.0 (74.0–84.0) for social support (range 12–84), 5.1 (4.7–5.4) for technology use (range 1–6), 54.0 (48.0–60.0) for mental well-being (range 14–70), and 319.0 (295.5–340) for self-efficacy (range 0–360). Social support was significantly associated with antenatal mental well-being adjusting for confounders [adj R2 = 0.13, p < .001]. The addition of technology use did not alter this model [adj R2 = 0.13, p < .001]. Social support was also significantly associated with self-efficacy after adjustment [adj R2 = 0.14, p < .001]; technology had limited impact on this association [adj R2 = 0.13, p < .001]. Conclusions: Social support is associated with mental well-being and self-efficacy in antenatal first-time mothers. This association was not significantly affected by general technology use as measured in our survey. Future work should investigate whether pregnancy-specific technologies yield greater potential to enhance the perceived social support, wellbeing and self-efficacy of antenatal women
Resolving the strange behavior of extraterrestrial potassium in the upper atmosphere
It has been known since the 1960s that the layers of Na and K atoms, which occur between 80 and 105 km in the Earth's atmosphere as a result of meteoric ablation, exhibit completely different seasonal behavior. In the extratropics Na varies annually, with a pronounced wintertime maximum and summertime minimum. However, K varies semiannually with a small summertime maximum and minima at the equinoxes. This contrasting behavior has never been satisfactorily explained. Here we use a combination of electronic structure and chemical kinetic rate theory to determine two key differences in the chemistries of K and Na. First, the neutralization of K+ ions is only favored at low temperatures during summer. Second, cycling between K and its major neutral reservoir KHCO3 is essentially temperature independent. A whole atmosphere model incorporating this new chemistry, together with a meteor input function, now correctly predicts the seasonal behavior of the K layer
Flow Dominance and Factorization of Transverse Momentum Correlations in Pb-Pb Collisions at the LHC
We present the first measurement of the two-particle transverse momentum differential correlation function, P2≡ ΔpTΔpT/ pT2, in Pb-Pb collisions at sNN=2.76 TeV. Results for P2 are reported as a function of the relative pseudorapidity (Δη) and azimuthal angle (Δφ) between two particles for different collision centralities. The Δφ dependence is found to be largely independent of Δη for |Δη|≥0.9. In the 5% most central Pb-Pb collisions, the two-particle transverse momentum correlation function exhibits a clear double-hump structure around Δφ=π (i.e., on the away side), which is not observed in number correlations in the same centrality range, and thus provides an indication of the dominance of triangular flow in this collision centrality. Fourier decompositions of P2, studied as a function of the collision centrality, show that correlations at |Δη|≥0.9 can be well reproduced by a flow ansatz based on the notion that measured transverse momentum correlations are strictly determined by the collective motion of the system
K*(892)(0) and phi(1020)meson production at high transverse momentum in pp and Pb-Pb collisions at root sNN=2.76 TeV
The production of K∗(892)0 and φ(1020) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions
at √sNN = 2.76 TeV has been analyzed using a high luminosity data sample accumulated in 2011 with the
ALICE detector at the Large Hadron Collider (LHC). Transverse momentum (pT) spectra have been measured
for K∗(892)0 and φ(1020) mesons via their hadronic decay channels for pT up to 20 GeV/c. The measurements
in pp collisions have been compared to model calculations and used to determine the nuclear modification factor
and particle ratios. The K∗(892)0/K ratio exhibits significant reduction from pp to central Pb-Pb collisions,
consistent with the suppression of the K∗(892)0 yield at low pT due to rescattering of its decay products in
the hadronic phase. In central Pb-Pb collisions the pT dependent φ(1020)/π and K∗(892)0/π ratios show an
enhancement over pp collisions for pT ≈ 3 GeV/c, consistent with previous observations of strong radial flow.
At high pT, particle ratios in Pb-Pb collisions are similar to those measured in pp collisions. In central Pb-Pb
collisions, the production of K∗(892)0 and φ(1020) mesons is suppressed for pT > 8 GeV/c. This suppression is
similar to that of charged pions, kaons, and protons, indicating that the suppression does not depend on particle
mass or flavor in the light quark sector
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