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1.
Ann Oncol ; 29(7): 1521-1527, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29718095

RESUMO

Background: Surrogate end points in rectal cancer after preoperative chemoradiation are lacking as their statistical validation poses major challenges, including confirmation based on large phase III trials. We examined the prognostic role and individual-level surrogacy of neoadjuvant rectal (NAR) score that incorporates weighted cT, ypT and ypN categories for disease-free survival (DFS) in 1191 patients with rectal carcinoma treated within the CAO/ARO/AIO-04 phase III trial. Patients and methods: Cox regression models adjusted for treatment arm, resection status, and NAR score were used in multivariable analysis. The four Prentice criteria (PC1-4) were used to assess individual-level surrogacy of NAR for DFS. Results: After a median follow-up of 50 months, the addition of oxaliplatin to fluorouracil-based chemoradiotherapy (CRT) significantly improved 3-year DFS [75.9% (95% confidence interval [CI] 72.30% to 79.50%) versus 71.3% (95% CI 67.60% to 74.90%); P = 0.034; PC 1) and resulted in a shift toward lower NAR groups (P = 0.034, PC 2) compared with fluorouracil-only CRT. The 3-year DFS was 91.7% (95% CI 88.2% to 95.2%), 81.8% (95% CI 78.4% to 85.1%), and 58.1% (95% CI 52.4% to 63.9%) for low, intermediate, and high NAR score, respectively (P < 0.001; PC 3). NAR score remained an independent prognostic factor for DFS [low versus high NAR: hazard ratio (HR) 4.670; 95% CI 3.106-7.020; P < 0.001; low versus intermediate NAR: HR 1.971; 95% CI 1.303-2.98; P = 0.001] in multivariable analysis. Notwithstanding the inherent methodological difficulty in interpretation of PC 4 to establish surrogacy, the treatment effect on DFS was captured by NAR, supporting satisfaction of individual-level PC 4. Conclusion: Our study validates the prognostic role and individual-level surrogacy of NAR score for DFS within a large randomized phase III trial. NAR score could help oncologists to speed up response-adapted therapeutic decision, and further large phase III trial data sets should aim to confirm trial-level surrogacy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia Adjuvante/mortalidade , Terapia Neoadjuvante/mortalidade , Neoplasias Retais/mortalidade , Neoplasias Retais/patologia , Idoso , Biomarcadores , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Masculino , Oxaliplatina/administração & dosagem , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias Retais/terapia , Taxa de Sobrevida
2.
J Phys Condens Matter ; 26(27): 275701, 2014 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-24925727

RESUMO

The effect of selenium substitution by sulphur on the structural and physical properties of antiferromagnetic TlFe1.6+δSe2 has been investigated via neutron, x-ray and electron diffraction, and transport measurements. The √5a×√5a×c super-cell related to the iron vacancy ordering found in the pure TlFe1.6Se2 selenide is also present in the S-doped TlFe1.6+δ(Se1-xSx)2 compounds. Neutron scattering experiments show the occurrence of the same long range magnetic ordering in the whole series i.e. the 'block checkerboard' antiferromagnetic structure. In particular, this is the first detailed study where the crystal structure and the √5a×√5a antiferromagnetic structure is characterized by neutron powder diffraction for the pure TlFe1.6+δS2 sulphide over a large temperature range. We demonstrate the strong correlation between occupancies of the crystallographic iron sites, the level of iron vacancy ordering and the occurrence of block antiferromagnetism in the sulphur series. Introducing S into the Se sites also increases the Fe content in TlFe1.6+δ(Se1-xSx)2 which in turn leads to the disappearance of the Fe vacancy ordering at x = 0.5 ± 0.15. However, by reducing the nominal Fe content, the same √5a×√5a×c vacancy ordering and antiferromagnetic order can be recovered also in the pure TlFe1.6+δS2 sulphide with a simultaneous reduction in the Néel temperature from 435 K in the selenide TlFe1.75Se2 to 330 K in the sulphide TlFe1.5S2. The magnetic moment remains high at low temperature throughout the full substitution range, which contributes to the absence of superconductivity in these compounds.


Assuntos
Ferro/química , Campos Magnéticos , Modelos Químicos , Selênio/química , Enxofre/química , Tálio/química , Simulação por Computador , Condutividade Elétrica , Transporte de Elétrons , Teste de Materiais , Difração de Nêutrons/métodos , Transição de Fase , Espalhamento de Radiação
3.
J Phys Condens Matter ; 25(7): 075703, 2013 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-23343616

RESUMO

The effect of selenium substitution by sulfur in the Tl(1-y)Fe(2-z)Se(2) antiferromagnet was studied by x-ray and electron diffraction, magnetization and transport measurements. Tl(0.8)Fe(1.5)(Se(1-x)S(x))(2) (nominal composition) solid solution was synthesized in the full x range (0 ≤ x(S) ≤ 1) using the sealed tube technique. No superconductivity was found down to 4.2 K in the series despite the fact that the optimal crystallographic parameters, determined by Rietveld refinements, are reached in the series (i.e. the Fe-(Se, S) interplane height and (Se, S)-Fe-(Se, S) angle for which the critical superconducting transition T(c) is usually maximal in pnictides). A quasi-full Tl site (y ~ 0.05) compared to significant alkaline deficiency (y = 0.2-0.3) in analogous A(1-y)Fe(2-z)Se(2) (A = K, Rb, Cs), and the resulting differences in iron valency, density of states and doping, are suggested as an explanation for this absence of superconductivity. Transmission electron microscopy confirmed the existence of an ordered iron vacancies network in the samples of the Tl(0.8)Fe(1.5)(Se(1-x)S(x))(2) series in the form of the tetragonal √5a × âˆš5a × c superstructure (I4/m). The Néel temperature (T(N)) indicating the onset of antiferromagnetism order in this √5a × âˆš5a × c supercell is found to decrease from 450 K in the selenide (x = 0) to 330 K in the sulfide (x = 1). Finally, we demonstrate a direct linear relationship between T(N) and the Fe-(Se, S) bond length (or Fe-(Se, S) height).


Assuntos
Modelos Químicos , Modelos Moleculares , Selênio/química , Enxofre/química , Tálio/química , Simulação por Computador , Transporte de Elétrons , Campos Magnéticos , Teste de Materiais
4.
Pathologe ; 31 Suppl 2: 211-4, 2010 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-20711583

RESUMO

To establish precise diagnostic algorithms and standardised treatment of sarcomas in specialized centers, the interdisciplinary research group KoSar (sarcoma competence network) has been funded by German Cancer Aid. A sarcoma tissue repository and a diagnostic reference center have been set up, presently containing about 1000 accurately diagnosed sarcomas of different entities. Significant gene expression profiles for synovial sarcomas, leiomyosarcomas, myxoid liposarcomas and a small profile for myxofibrosarcomas as well as a new classification of angiosarcomas were defined. We systematically searched for activated signal transduction pathways in sarcoma cell lines and xenograft transplant models and candidate targets for molecular therapies were identified. Based on these results first clinical studies have been initiated by the German Interdisciplinary Sarcoma Study Group (GISG).


Assuntos
Sarcoma/genética , Sarcoma/patologia , Animais , Pesquisa Biomédica , Linhagem Celular Tumoral , Comportamento Cooperativo , Avaliação Pré-Clínica de Medicamentos , Fibrossarcoma/diagnóstico , Fibrossarcoma/tratamento farmacológico , Fibrossarcoma/genética , Fibrossarcoma/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Comunicação Interdisciplinar , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/tratamento farmacológico , Leiomiossarcoma/genética , Leiomiossarcoma/patologia , Lipossarcoma Mixoide/diagnóstico , Lipossarcoma Mixoide/tratamento farmacológico , Lipossarcoma Mixoide/genética , Lipossarcoma Mixoide/patologia , Técnicas de Diagnóstico Molecular , Terapia de Alvo Molecular , Transplante de Neoplasias , Sarcoma/diagnóstico , Sarcoma/tratamento farmacológico , Sarcoma Sinovial/diagnóstico , Sarcoma Sinovial/tratamento farmacológico , Sarcoma Sinovial/genética , Sarcoma Sinovial/patologia , Transdução de Sinais/genética
5.
Eur J Clin Nutr ; 57(3): 439-46, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12627181

RESUMO

OBJECTIVE: (1) To compare the effect of an alcohol-free Mediterranean-type diet (MD) and a high-fat diet (HFD) on variables of primary haemostasis (bleeding time, plasma von Willebrand factor and platelet aggregation/secretion). (2) To test whether red wine supplementation modified these variables, independently of the diet. DESIGN, SUBJECTS AND INTERVENTION: Controlled prospective intervention study. Two groups, each consisting of 21 healthy male university students (22+/-3.4 y), received either MD or HFD during 90 days. Between days 30 and 60, both diets were supplemented with 240 ml/day of red wine. Baseline (T0) and T30, T60 and T90-day samples were drawn. Bleeding time was measured before (day 30) and after (day 60) wine supplementation. No drop out from the study was experienced. SETTING: University campus and outpatient nutrition clinic. RESULTS: All baseline (day 0) variables did not differ significantly between study groups. On day 30, individuals on MD had significantly higher levels of plasma beta-carotene, folate, ascorbate, and eicosapentaenoic acid in plasma lipid fractions, than those on HFD. Total plasma cholesterol, HDL and LDL did not change significantly in either study group at any time point. After 30 days on each diet, individuals on MD had longer bleeding time (BT) than those on HFD (7.6+/-2.8 vs 5.8+/-1.7 min; P=0.017). BT did not change significantly after I month of wine supplementation (7.1+/-2.0 vs 5.5+/-2.0 min, respectively). Plasma von Willebrand factor (vWF : Ag) on day 0 was 89+/-40 and 111+/-70% in MD and HFD groups, respectively (P=0.21). These values did not change significantly at 30, 60 or 90 days. MD intake was associated with an increase in platelet serotonin secretion (P=0.02) and a marginal increase in platelet aggregation after stimulation with epinephrine (P=0.07). Wine intake resulted in a marginal decrease in platelet (14)C-5-HT secretion with 4 micro M ADP (P=0.07). However, both platelet aggregation and secretion were consistently increased when using collagen as agonist (1 and 2 micro g/ml, P=0.01). CONCLUSION: The longer BT in individuals on MD, obtained independently of red wine, denotes less interaction of platelets with the vascular wall, which could be beneficial from the point of view of cardiovascular (CV) risk. This effect is not explained by changes in the measured haemostatic determinants of BT (plasma vWF, ex vivo platelet function), and might be attributed to other as yet unknown vascular factors. Moderate consumption of red wine results in a significant increase in ex vivo platelet aggregation and secretion after stimulation with collagen. This observation contradicts previous reports, although further studies are required to elucidate the influence of this finding on CV risk.


Assuntos
Dieta Mediterrânea , Gorduras na Dieta/administração & dosagem , Hemostasia/fisiologia , Vinho , Adulto , Tempo de Sangramento , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Colágeno/farmacologia , Hemostasia/efeitos dos fármacos , Humanos , Lipídeos/sangue , Masculino , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Estudos Prospectivos , Fatores de Risco , Serotonina/metabolismo , Vinho/análise , Fator de von Willebrand/análise
6.
Thromb Res ; 100(3): 153-60, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11108902

RESUMO

Hyperhomocysteinemia in association with vitamin B(12) deficiency, and increased platelet aggregation, probably due to dietary lack of n-3 fatty acids, constitute cardiovascular risk factors frequently observed in vegetarians. We tested if administration of vitamin B(12) normalizes the concentration of total plasma homocysteine, and if intake of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) fatty acids modulates platelet function in a population of lactoovovegetarians. One week after a single intramuscular injection of cyanocobalamin (10000 microg) in 18 individuals, serum vitamin B(12) increased from 149+/-63 pg/mL to 532+/-204 pg/mL (p<0.0001) and total tHcy dropped from 12.4+/-4.7 to 7.9+/-3.1 micromol/L (p<0. 0001). Ten of fourteen of these vegetarians completed an 8-week supplementation with 700 mg/day of each eicosapentaenoic and docosahexaenoic acids. Increased incorporation of these fatty acids into plasma lipids was observed in all of them, together with a significant reduction in maximum percentage or slope of platelet aggregation with all the agonists tested (ADP, epinephrin, collagen, arachidonic acid). No significant change in bleeding time was observed after n-3 fatty acid trial. Supplementation with vitamin B(12) and n-3 fatty acids corrects hyperhomocysteinemia and reduces platelet reactivity to agonists in vegetarians. Whether this supplementation improves the already reduced cardiovascular morbidity and mortality associated with vegetarian diet has yet to be demonstrated.


Assuntos
Doenças Cardiovasculares/dietoterapia , Dieta Vegetariana/efeitos adversos , Adulto , Doenças Cardiovasculares/prevenção & controle , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/farmacocinética , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/farmacocinética , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-3/farmacocinética , Feminino , Humanos , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/etiologia , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Fatores de Risco , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Vitamina B 12/farmacocinética
7.
Lipids ; 35(2): 143-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10757544

RESUMO

Endothelial dysfunction is associated with atherogenesis and oxidative stress in humans. In rat and rabbit blood vessels, wine polyphenol antioxidants induce vascular relaxation in vitro through the NO-cGMP pathway. To assess the effect of a regular high-fat diet (HFD) and moderate red wine consumption on endothelial function (EF), a study was performed in healthy male volunteers. EF was measured as flow-mediated dilatation of the brachial artery, employing high-resolution ultrasound after an overnight fast. Other clinical and biochemical parameters related to EF were also measured. Six volunteers received a control diet, rich in fruits and vegetables (27% calories as fat) and five volunteers received an HFD (39.5% calories as fat). Measurements were done twice on each volunteer: after a period of 30 d with diet plus 240 mL of red wine/d, and after a period of 30 d with diet, without wine. In the absence of wine, there is a reduction of EF with HFD when compared to the control diet (P = 0.014). This loss of EF is not seen when both diets are supplemented with wine for 30 d (P = 0.001). Plasma levels of n-3 fatty acids (R2 = 0.232, P = 0.023) and lycopene (R2 = 0.223, P = 0.020) show a positive correlation with individual EF measurements, but they do not account for the significant differences observed among dietary groups or after wine supplementation. These results help elucidate the deleterious effect of a high-fat diet and the protective role of wine, n-3 fatty acids and dietary antioxidants in cardiovascular disease.


Assuntos
Gorduras na Dieta/efeitos adversos , Endotélio Vascular/fisiologia , Vinho , Fosfatase Alcalina/sangue , Artéria Braquial/efeitos dos fármacos , Artéria Braquial/fisiologia , Dieta , Endotélio Vascular/efeitos dos fármacos , Ácidos Graxos/sangue , Ácidos Graxos Ômega-3/sangue , Frutas , Homocisteína/sangue , Humanos , Masculino , Nitroglicerina/farmacologia , Transaminases/sangue , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Verduras , Vitamina B 12/sangue , gama-Glutamiltransferase/sangue
8.
Drugs Exp Clin Res ; 25(2-3): 133-41, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10370876

RESUMO

An intervention study was performed to evaluate the influence of a Mediterranean diet, a high fat diet, and their supplementation with red wine in moderate amounts, on biochemical, physiological, and clinical parameters related to atherosclerosis and other chronic diseases. For 3 months two groups of 21 male volunteers each, received either a Mediterranean diet or a high fat diet; during the second month, red wine was added isocalorically, 240 ml/day. Participants were kept under close medical and nutritional surveillance. At days 0, 30, 60 and 90, clinical, physiological and biochemical evaluations were made. Plasma vitamin C was significantly decreased in the high fat diet group compared to the Mediterranean diet group. After wine supplementation to the Mediterranean diet, a significant 13.5% increase in plasma vitamin C was observed. Furthermore, when wine was added vitamin E decreased significantly in plasma, 15% in the high fat diet and 26% in the Mediterranean diet. Total plasma antioxidant capacity (total antioxidant reactivity) increased 28% above basal levels in the Mediterranean diet group, but not in the high fat diet group. In both groups, wine induced a marked increase in total antioxidant reactivity above basal levels, 56% and 23%, respectively. Oxidative DNA damage, detected as 8-hydroxydeoxyguanosine (8-OHdG) levels in blood leukocyte DNA, was markedly increased by the high fat diet; however, it was strongly reduced, to approximately 50% basal values, after wine supplementation, both in the high fat diet and Mediterranean diet groups. Endothelial function, evaluated noninvasively as flow-mediated vascular reactivity of the brachial artery, was suppressed by the high fat diet, and was normal after wine supplementation. These effects are attributed to oxidative stress associated with a high fat diet, and to the elevated plasma antioxidant capacity associated with wine consumption and the Mediterranean diet. The results presented support the following conclusions: a high fat diet induces oxidative stress; a diet rich in fruits and vegetables enhances antioxidant defenses; wine supplementation to a high fat or a Mediterranean diet increases plasma antioxidant capacity, decreases oxidative DNA damage, and normalizes endothelial function.


Assuntos
Antioxidantes/análise , Dano ao DNA/efeitos dos fármacos , Dieta Aterogênica , Gorduras na Dieta , Flavonoides , Fenóis/sangue , Fenóis/metabolismo , Polímeros/metabolismo , Vinho/análise , Adulto , Arteriosclerose/prevenção & controle , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Humanos , Metabolismo dos Lipídeos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Polifenóis
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