89 research outputs found

    Development of a novel nomogram-based online tool to predict axillary status after neoadjuvant chemotherapy in cN+ breast cancer: A multicentre study on 1,950 patients

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    Background: Type of axillary surgery in breast cancer (BC) patients who convert from cN + to ycN0 after neoadjuvant chemotherapy (NAC) is still debated. The aim of the present study was to develop and validate a preoperative predictive nomogram to select those patients with a low risk of residual axillary disease after NAC, in whom axillary surgery could be minimized. Patients and methods: 1950 clinically node-positive BC patients from 11 Breast Units, treated by NAC and subsequent surgery, were included from 2005 to 2020. Patients were divided in two groups: those who achieved nodal pCR vs. those with residual nodal disease after NAC. The cohort was divided into training and validation set with a geographic separation criterion. The outcome was to identify independent predictors of axillary pathologic complete response (pCR). Results: Independent predictive factors associated to nodal pCR were axillary clinical complete response (cCR) after NAC (OR 3.11, p < 0.0001), ER-/HER2+ (OR 3.26, p < 0.0001) or ER+/HER2+ (OR 2.26, p = 0.0002) or ER-/HER2- (OR 1.89, p = 0.009) BC, breast cCR (OR 2.48, p < 0.0001), Ki67 > 14% (OR 0.52, p = 0.0005), and tumor grading G2 (OR 0.35, p = 0.002) or G3 (OR 0.29, p = 0.0003). The nomogram showed a sensitivity of 71% and a specificity of 73% (AUC 0.77, 95%CI 0.75\u20130.80). After external validation the accuracy of the nomogram was confirmed. Conclusion: The accuracy makes this freely-available, nomogram-based online tool useful to predict nodal pCR after NAC, translating the concept of tailored axillary surgery also in this setting of patients

    Whole body vibration: What is all the fuss about?

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    Whole body vibration (WBV) has been promoted in the market as a new method for exercising, by which 10min are more than enough for the fitness training of busy, modern people. Several companies have been over-stating the positive effects that this type of exercise has on the human body, advertising the general improvement in strength, flexibility and neuromuscular performance granted through it. The question needs to be asked: ‘Does WBV do what it is said to be doing?’. © 2010, MA Healthcare Ltd. All rights reserved

    Theoretical and experimental study of flavones as inhibitors of xanthine oxidase

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    Inhibitory activities of 19 polyhydroxylated and polymethoxylated flavones towards xanthine oxidase have been obtained by accurate measurements of the dissociation constants of enzyme-inhibitor complexes (K-EI). A topological description of the congeneric series has been adopted to derive quantitative structure-activity relationships (QSAR) with the use of multiple linear regression analysis. For interpretative purposes, molecular orbital calculations have also been performed. Inhibition appears to involve flavones as donors and the anion at the C-7 hydroxyl as the most active form in solution. Substituents in the 4H-1-benzopyran-4-one moiety can directly affect the availability of the C-7 anion in solution; substituents in the 2-phenyl moiety are probably involved in secondary local interactions with the enzyme

    Physico-chemical properties of anthocyanidins. Part 1. Theoretical evaluation of the stability of the neutral and anionic tautomeric forms

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    Quantum chemical (AM1) and solvation model calculations have been applied to the study of tautomeric stabilities in three anthocyanidins, so as to single out the dominant tautomeric forms (neutral and anionic) at physiological pH. The theoretical information concerning the tautomeric stabilities and electronic structures of anthocyanidins are essential for the development of quantitative structure-activity relationships. The present results allow us to discriminate between the wide variety of tautomeric forms, and to infer that, depending on the pH, only two neutral tautomers and two anionic tautomers should be present in solution. On interpretative grounds, the main factors determining stability are chiefly ascribable to the extent of pi-electron delocalization and to the possibility of classical resonance structures. Several theoretical descriptors have been calculated for use in quantitative structure-activity relationships

    A rational approach to the design of flavones as xanthine oxidase inhibitors

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    In the light of previous QSAR studies on flavones as inhibitors of xanthine oxidase, we synthesized and tested a new series of 7-hydroxyflavones carrying a wide and balanced variety of substituents (pi, sigma(p)) at the 4' position in order to explore the effect of substituents at this position on the xanthine oxidase inhibitory activity. The results of pK(a) determinations show that the electronic effects of the substituents are not transferred to the hydroxyl at C7, previously found to be fundamental for activity. An excellent correlation is found between molar refractivity of the substituents and the inhibitory activity. These results, applied to the more active 5,7-dihydroxyflavones, allowed the design and synthesis of a very active inhibitor, with an IC50 in the nanomolar range. On interpretative grounds, C4' substituents of flavones are involved in dispersion interactions with the enzyme. The calculation of quantum chemical polarizabilities and solvent accessible surface areas suggests the existence of pi-pi stacking interactions with an aromatic aminoacidic residue of the enzyme

    Solvent effects on the tautomerism of apigeninidin

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    Solvent effects are found to be responsible for the predominance in water solution of a highly unstable tautomer of apigeninidin in vacuo. We present free energy perturbation in molecular dynamics simulations and self-consistent reaction field calculations of the relative solvation of the anionic tautomers of apigeninidin
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