136 resultados para substitution reactions on phosphane ligands


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BACKGROUND: Ethanol can account for up to 10 percent of the energy intake of persons who consume moderate amounts of ethanol. Its effect on energy metabolism, however, is not known. METHODS: We studied the effect of ethanol on 24-hour substrate-oxidation rates in eight normal men during two 48-hour sessions in an indirect-calorimetry chamber. In each session, the first 24 hours served as the control period. On the second day of one session, an additional 25 percent of the total energy requirement was added as ethanol (mean [+/- SD], 96 +/- 4 g per day); during the other session, 25 percent of the total energy requirement was replaced by ethanol, which was isocalorically substituted for lipids and carbohydrates. RESULTS: Both the addition of ethanol and the isocaloric substitution of ethanol for other foods reduced 24-hour lipid oxidation. The respective mean (+/- SE) decreases were 49.4 +/- 6.7 and 44.1 +/- 9.3 g per day (i.e., reductions of 36 +/- 3 percent and 31 +/- 7 percent from the oxidation rate during the control day; P less than 0.001 and P less than 0.0025). This effect occurred only during the daytime period (8:30 a.m. to 11:30 p.m.), when ethanol was consumed and metabolized. Neither the addition of ethanol to the diet nor the isocaloric substitution of ethanol for other foods significantly altered the oxidation of carbohydrate or protein. Both regimens including ethanol produced an increase in 24-hour energy expenditure (7 +/- 1 percent with the addition of ethanol, P less than 0.001; 4 +/- 1 percent with the substitution of ethanol for other energy sources, P less than 0.025). CONCLUSIONS: Ethanol, either added to the diet or substituted for other foods, increases 24-hour energy expenditure and decreases lipid oxidation. Habitual consumption of ethanol in excess of energy needs probably favors lipid storage and weight gain.

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The process of on-line generation of ultrapure dialysis fluid is a core prerequisite for the safe execution of modern renal replacement therapies such as on-line hemodiafiltration and high-flux hemodialysis. In these extracorporeal treatments with variable degrees of convection, significant volumes of plasma water are removed and replaced with dialysis fluid, which must occur without causing harm to the patient. Historically, on-line generation of sterile and pyrogen-free physiological substitution fluid by the process of membrane ultrafiltration of fresh dialysis fluid has its origin in hemofiltration, a purely convective therapy. Development of this and later therapies is described in the historical context of a successful effort over decades to overcome the above formidable challenge, which was provided jointly by pioneering clinical investigators and a resourceful dialysis industry.

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New triruthenium-carbonyl clusters derivatized with glucose-modified bicyclophosphite ligands have been synthesized. These compounds were found to have cytostatic and cytotoxic activity and depending on the number of bicyclophosphite ligands, and could be tuned for either anti-cancer or specific anti-angiogenic activity. While some compounds had a broad cellular toxicity profile in several cell types others showed endothelial cell specific dose-dependent anti-proliferative and anti-migratory efficacy. A profound inhibition of angiogenesis was also observed in the in vivo chicken chorioallantoic membrane (CAM) model, and consequently, these new compounds have considerable potential in drug design, e.g. for the treatment of cancer.

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BACKGROUND: Synthetic contiguous overlapping peptides (COPs) may represent an alternative to allergen extracts or recombinant allergens for allergen specific immunotherapy. In combination, COPs encompass the entire allergen sequence, providing all potential T cell epitopes, while preventing IgE conformational epitopes of the native allergen. METHODS: Individual COPs were derived from the sequence of Bet v 1, the major allergen of birch pollen, and its known crystal structure, and designed to avoid IgE binding. Three sets of COPs were tested in vitro in competition ELISA and basophil degranulation assays. Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen. RESULTS: The combination, named AllerT, of three COPs selected for undetectable IgE binding in competition assays and for the absence of basophil activation in vitro was unable to induce anaphylaxis in sensitized mice in contrast to rBet v 1. In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen. In contrast, a second set of COPs, AllerT4-T5 displayed some residual IgE binding in competition ELISA and a weak subliminal reactivity to skin prick testing. CONCLUSIONS: The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human. TRIAL REGISTRATION: ClinicalTrials.gov NCT01719133.

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Background: Since generic drugs have the same therapeutic effect as the original formulation but at generally lower costs, their use should be more heavily promoted. However, a considerable number of barriers to their wider use have been observed in many countries. The present study examines the influence of patients, physicians and certain characteristics of the generics' market on generic substitution in Switzerland.Methods: We used reimbursement claims' data submitted to a large health insurer by insured individuals living in one of Switzerland's three linguistic regions during 2003. All dispensed drugs studied here were substitutable. The outcome (use of a generic or not) was modelled by logistic regression, adjusted for patients' characteristics (gender, age, treatment complexity, substitution groups) and with several variables describing reimbursement incentives (deductible, co-payments) and the generics' market (prices, packaging, co-branded original, number of available generics, etc.).Results: The overall generics' substitution rate for 173,212 dispensed prescriptions was 31%, though this varied considerably across cantons. Poor health status (older patients, complex treatments) was associated with lower generic use. Higher rates were associated with higher out-of-pocket costs, greater price differences between the original and the generic, and with the number of generics on the market, while reformulation and repackaging were associated with lower rates. The substitution rate was 13% lower among hospital physicians. The adoption of the prescribing practices of the canton with the highest substitution rate would increase substitution in other cantons to as much as 26%.Conclusions: Patient health status explained a part of the reluctance to substitute an original formulation by a generic. Economic incentives were efficient, but with a moderate global effect. The huge interregional differences indicated that prescribing behaviours and beliefs are probably the main determinant of generic substitution.

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BACKGROUND: Hypertension can be controlled adequately with existing drugs such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Nevertheless, treatment success is often restricted by patients not adhering to treatment. Immunisation against angiotensin II could solve this problem. We investigated the safety and efficacy of CYT006-AngQb-a vaccine based on a virus-like particle-that targets angiotensin II to reduce ambulatory blood pressure. METHODS: In this multicentre, double-blind, randomised, placebo-controlled phase IIa trial, 72 patients with mild-to-moderate hypertension were randomly assigned with a computer-generated randomisation list to receive subcutaneous injections of either 100 mug CYT006-AngQb (n=24), 300 mug CYT006-AngQb (24), or placebo (24), at weeks 0, 4, and 12. 24-h ambulatory blood pressure was measured before treatment and at week 14. The primary outcomes were safety and tolerability. Analyses were done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00500786. FINDINGS: Two patients in the 100 mug group, three in the 300 mug group, and none in the placebo group discontinued study treatment. All patients were included in safety analyses; efficacy analyses did not include the five dropouts, for whom no data were available at week 14. Five serious adverse events were reported (two in the 100 mug group, two in the 300 mug group, and one in the placebo group); none were deemed to be treatment related. Most side-effects were mild, transient reactions at the injection site. Mild, transient influenza-like symptoms were seen in three patients in the 100 mug group, seven in the 300 mug group, and none in the placebo group. In the 300 mug group, there was a reduction from baseline in mean ambulatory daytime blood pressure at week 14 by -9.0/-4.0 mm Hg compared with placebo (p=0.015 for systolic and 0.064 for diastolic). The 300 mug dose reduced the early morning blood-pressure surge compared with placebo (change at 0800 h -25/-13 mm Hg; p<0.0001 for systolic, p=0.0035 for diastolic). INTERPRETATION: Immunisation with CYT006-AngQb was associated with no serious adverse events; most observed adverse events were consistent with local or systemic responses similar to those seen with other vaccines. The 300 mug dose reduced blood pressure in patients with mild-to-moderate hypertension during the daytime, especially in the early morning. FUNDING: Cytos Biotechnology AG.

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The mechanism of action of 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) involves the carrier-mediated and potentially vesicular release of monoamines. We assessed the effects of the sympatholytic α₂-adrenergic receptor agonist clonidine (150 μg p.o.), which inhibits the neuronal vesicular release of norepinephrine, on the cardiovascular and psychotropic response to MDMA (125 mg p.o.) in 16 healthy subjects. The study used a randomized, double-blind, placebo-controlled crossover design with four experimental sessions. The administration of clonidine 1 h before MDMA reduced the MDMA-induced increases in plasma norepinephrine concentrations and blood pressure but only to the extent that clonidine lowered norepinephrine levels and blood pressure compared with placebo. Thus, no interaction was found between the cardiovascular effects of the two drugs. Clonidine did not affect the psychotropic effects or pharmacokinetics of MDMA. The lack of an interaction of the effects of clonidine and MDMA indicates that vesicular release of norepinephrine, which is inhibited by clonidine, does not critically contribute to the effects of MDMA in humans. Although clonidine may be used in the treatment of stimulant-induced hypertensive reactions, the present findings do not support a role for α₂-adrenergic receptor agonists in the prevention of psychostimulant dependence.

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Despite a wealth of data on the neurotoxic effects of lead at the cellular and molecular levels, the reasons for its development-dependent neurotoxicity are still unclear. Here, the maturation-dependent effects of lead acetate were analyzed in immature and differentiated brain cells cultured in aggregates. Markers of general cytotoxicity as well as cell-type-specific markers of glial and neuronal cells showed that immature brain cells were more sensitive to lead than the differentiated counterparts, demonstrating that the development-dependent neurotoxicity of lead can be reproduced in aggregating brain cell cultures. After 10 days of treatment, astrocytes were found to be more affected by lead acetate than neurons in immature cultures, and microglial cells were strongly activated. Eleven days after cessation of the treatment, lead acetate caused a partial loss of astrocytes and an intense reactivity of the remaining ones. Furthermore, microglial cells expressed a macrophagic phenotype, and the loss of activity of neuron-specific enzymes was aggravated. In differentiated cultures, no reactive gliosis was found. It is hypothetized that the intense glial reactions (microgliosis and astrogliosis) observed in immature cultures contribute to the development-dependent neurotoxicity of lead.

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Diruthenium tetracarbonyl complexes of the type [Ru2(CO)4(l2-g2-O2CR)2L2] containing a Ru-Ru backbone with four equatorial carbonyl ligands, two carboxylato bridges, and two axial two-electron ligands in a sawhorse-like geometry have been synthesized with porphyrin-derived substituents in the axial ligands [1: R is CH3, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin], in the bridging carboxylato ligands [2: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is PPh3; 3: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 1,3,5-triaza-7-phosphatricyclo [3.3.1.1]decane], or in both positions [4: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin]. Compounds 1-3 were assessed on different types of human cancer cells and normal cells. Their uptake by cells was quantified by fluorescence and checked by fluorescence microscopy. These compounds were taken up by human HeLa cervix and A2780 and Ovcar ovarian carcinoma cells but not by normal cells and other cancer cell lines (A549 pulmonary, Me300 melanoma, PC3 and LnCap prostate, KB head and neck, MDAMB231 and MCF7 breast, or HT29 colon cancer cells). The compounds demonstrated no cytotoxicity in the absence of laser irradiation but exhibited good phototoxicities in HeLa and A2780 cells when exposed to laser light at 652 nm, displaying an LD50 between 1.5 and 6.5 J/cm2 in these two cell lines and more than 15 J/cm2 for the others. Thus, these types of porphyric compound present specificity for cancer cell lines of the female reproductive system and not for normal cells; thus being promising new organometallic photosensitizers.

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Cadre de l'étude La part des dépenses de santé dans les budgets des pays occidentaux est importante et tend à croître depuis plusieurs décennies. Une des conséquences, notamment pour la Suisse, est une augmentation régulière des primes d'assurance maladie, dont l'impopularité incite les responsables politiques à trouver des stratégies de frein à la croissance des coûts de la santé. Les médicaments, qui contribuent notablement à l'augmentation de ces coûts, constituent l'une des cibles classiques d'interventions visant à une réduction des dépenses de santé. Le niveau de coûts des médicaments représente plus de 20% des dépenses de soins du domaine ambulatoire à la charge de l'assurance obligatoire des soins (AOS), soit une dépense annuelle de plus de 4 milliards de francs. Différentes mesures peuvent être utilisées par le gouvernement pour contenir cette facture à charge de la collectivité : baisse du prix des médicaments, limitation du nombre de produits remboursés par l'assurance de base et incitations à la concurrence sur les prix en autorisant les importations parallèles. Depuis que de plus en plus de brevets pour des médicaments sont arrivés à échéance, un autre angle d'attaque s'est concrétisé avec l'incitation à la prescription de médicaments génériques. Les génériques sont définis comme des produits thérapeutiques chimiquement identiques à des composés déjà utilisés, appelés médicaments originaux. En principe, une économie substantielle devrait pouvoir être réalisée sur les coûts totaux des médicaments si tous les génériques disponibles sur le marché étaient systématiquement prescrits par les professionnels et acceptés par les patients. Les résultats publiés par les caisses maladie et les offices fédéraux sont des estimations globales et les montants publiés par l'industrie pharmaceutique concernent l'ensemble du marché, incluant les médicaments utilisés dans les séjours hospitaliers, sont par ailleurs exprimés en prix de fabrique. De plus, aucune étude n'a tenu compte de la substituabilité des produits d'un point de vue pharmaceutique. L'objectif général de la thèse est d'évaluer aussi précisément que possible l'économie pouvant être encore réalisée dans le secteur ambulatoire en substituant aux médicaments originaux les produits génériques présents sur le marché et de caractériser plusieurs facteurs qui influencent la substitution générique. Pour cette étude, nous avons pu disposer de l'ensemble des factures pharmaceutiques de la caisse maladie CSS, pour tous ses assurés des cantons d'Argovie, du Tessin et de Vaud, soit plus de 169'000 assurés représentant les trois régions linguistiques de la Suisse. Les 1'341'197 prescriptions médicales qui ont été analysées concernent l'année 2003. C'est un moment critique dans l'histoire des génériques en Suisse, approprié pour établir un premier bilan après l'entrée en vigueur de la première mesure relative au droit de substituer octroyé en 2001 aux pharmaciens et, pour identifier idéalement les principaux déterminants de la substitution par les praticiens avant l'introduction de la quote-part différenciée en 2006. La présence d'un même principe actif n'est pas une condition suffisante pour permettre une substitution et pour ce travail des critères tenant compte des caractéristiques pharmaceutiques des produits ont été établis et appliqués pour valider la substituabilité des originaux par les génériques disponibles sur le marché. Ces critères concernent notamment le mode d'administration, le dosage et le nombre de doses dans l'emballage. L'étude a été réalisée selon deux approches, d'abord par une analyse descriptive sur l'ensemble de la population source pour estimer le marché des génériques et ensuite par une analyse statistique (régression logit multivariée) sur 173'212 prescriptions agrégées, qui concernent spécifiquement soit un générique soit un original substituable, pour caractériser les facteurs déterminants de la substitution générique. Résultats Dans l'ensemble de la population source, les génériques et les originaux substituables représentent 17,4% du marché en termes de coûts facturés, avec 3,4% de génériques et 14,0% d'originaux substituables ce qui correspond à un taux de substitution de 19,5%. En termes de dépenses, les substitutions génériques réalisées représentent une économie de 1,3% du total du marché étudié alors qu'il reste un potentiel notable d'économie par la substitution de 4,6%. Les taux de substitution sont très variables selon les cantons : 10,1% au Tessin, 29,0% pour le canton de Vaud et 35,8% pour Argovie. L'analyse univariée des 173'212 prescriptions de génériques ou d'originaux substituables, montre des taux de substitution plus élevés chez les patients jeunes et lorsqu'il y a d'importantes différences de prix entre les originaux et les génériques. Des taux de substitution peu élevés sont observés chez les patients les plus âgés et pour ceux qui ont des traitements médicamenteux complexes. Les patients ayant plus de 10 médicaments différents durant la même année, présentent une probabilité relative de substituer inférieure (-24%) par rapport aux patients ayant 6 à 10 médicaments différents dans l'année. Cependant, l'analyse multivariée montre que l'effet négatif sur le taux de substitution de l'âge combiné à la complexité des traitements n'excède pas 3%. Bien que le niveau de franchises et la participation financière à la quote-part soient liées à une augmentation de la prescription de génériques, leurs effets sont modérés pour les patients avec des franchises supérieures à 300 francs (effet marginal de 1%) et pour les patients qui n'ont pas atteint le plafond de participation (effet marginal de 2%). La différence de taux substitution entre les médecins hospitaliers et les spécialistes est diminuée de façon notable (effet marginal de -13%) et elle est cependant moins marquée avec les médecins généralistes (effet marginal de -3%). Les facteurs associés au marché ont une influence notable sur la substitution générique et des effets positifs sont observés avec l'augmentation de la taille du marché, du nombre de génériques pour un même original substituable et de l'économie relative entre l'original et le générique. Par contre, la diversification des formes galéniques et des tailles d'emballages au niveau de l'offre des médicaments originaux a des effets fortement négatifs sur la substitution générique (-7%). Le canton de domicile a aussi un impact notable sur la substitution et le canton du Tessin présente un taux plus bas (-26%) que le canton d'Argovie. Conclusion et perspectives Ce travail a montré qu'il y a encore un important potentiel d'économies à réaliser par la substitution générique, calculé à plus de 4% des dépenses pharmaceutiques prises en charge par l'AOS en ambulatoires. Une extrapolation à l'ensemble du marché suisse, qui doit être faite avec prudence, fait apparaître un potentiel d'économies de 127 millions pour les médicaments délivrés par les pharmacies en 2003. L'étude a mis en évidence un certain nombre de déterminants qui freinent la substitution générique, notamment la prescription par un médecin hospitalier. Sur ce point la prescription en DCI (dénomination commune internationale) pourrait favoriser la dispensation de génériques moins chers. Un taux de substitution plus faible est observé chez les patients âgés avec des traitements complexes. Ce constat peut être mis en relation avec la crainte d'avoir un traitement moins efficace ou moins bien supporté et les risques de confusion lors du passage d'un original substituable à un générique ou d'un générique à un autre générique. Sur ces éléments, l'indication claire et précise du nom de la substance, aussi bien sur les emballages des originaux substituables que sur ceux des génériques, pourrait rassurer les patients et diminuer les risques d'erreurs dans la prise des médicaments. Certaines précautions à prendre lors de la prescription de génériques sont reconnues, notamment pour les médicaments à faible marge thérapeutique, et des informations sur la bioéquivalence, régulièrement mises à jour et à disposition des professionnels, pourraient augmenter la confiance dans l'utilisation des génériques. Les industries pharmaceutiques préservent par différentes tactiques leurs parts de marché et notamment avec succès en introduisant de nouvelles formes galéniques juste avant l'expiration des brevets. Des directives complémentaires sur la fixation des prix pour le remboursement, en particulier l'introduction d'un prix de référence quelle que soit la forme galénique, pourraient diminuer l'effet de barrage des médicaments originaux. Les incitations économiques, telles que la franchise et les participations sont efficaces si l'on considère l'impact sur les taux de substitution. Leur effet global reste toutefois modeste et il serait nécessaire de mesurer concrètement l'impact de l'introduction en 2006 de la quote-part différenciée. Les différences de prix entre les originaux et les génériques exigées à 50% pour les gros marchés, c'est-à-dire de plus de 16 millions, devraient aussi avoir un impact qu'il serait opportun de mesurer.

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The costs of coping with stressful situations are traded-off against other functions such as immune responses. This trade-off may explain why corticosterone secretion reduces immune reactions. Corticosterone differentially affects various immunity components. However, which component is suppressed varies between studies. It remains unclear whether the trade-off in energy, nutrition, autoimmunity or oxidative stress accounts for differential immunosuppression. In this study, we investigated whether corticosterone differentially affects the constitutive innate and humoral acquired immunity. We used barn owl nestlings, implanting 50% with a corticosterone-releasing pellet and the other 50% with a placebo pellet. To measure the effect on humoral immunity we vaccinated 50% of the corticosterone-nestlings and 50% of the placebo-nestlings with the antigens 'Tetravac' and the other 50% were injected with PBS. To assess the costs of elevated corticosterone, we measured body mass and resistance to oxidative stress. Administration of corticosterone increased corticosterone levels whereas vaccination induced the production of antibodies. Corticosterone reduced the production of antibodies, but it did not significantly affect the constitutive innate immunity. Corticosterone reduced body growth and resistance to oxidative stress. Under stressful conditions barn owl nestlings seem to keep the constitutive innate immunity, whereas elevated corticosterone levels negatively affected inducible immune responses. We found evidence that mounting a humoral immune reaction is not costly in terms of growth, but reduces the resistance to oxidative stress independently of corticosterone administration. We suggest that humoral immunity is suppressed because the risk of immunopathologies may be disproportionately high when mounting an antibody response under stressful situations.

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P-selectin glycoprotein ligand-1 (PSGL-1) mediates the capture (tethering) of free-flowing leukocytes and subsequent rolling on selectins. PSGL-1 interactions with endothelial selectins activate Src kinases and spleen tyrosine kinase (Syk), leading to α(L)β(2) integrin-dependent leukocyte slow rolling, which promotes leukocyte recruitment into tissues. In addition, but through a distinct pathway, PSGL-1 engagement activates ERK. Because ezrin, radixin and moesin proteins (ERMs) link PSGL-1 to actin cytoskeleton and because they serve as adaptor molecules between PSGL-1 and Syk, we examined the role of PSGL-1 ERM-binding sequence (EBS) on cell capture, rolling, and signaling through Syk and MAPK pathways. We carried out mutational analysis and observed that deletion of EBS severely reduced 32D leukocyte tethering and rolling on L-, P-, and E-selectin and slightly increased rolling velocity. Alanine substitution of Arg-337 and Lys-338 showed that these residues play a key role in supporting leukocyte tethering and rolling on selectins. Importantly, EBS deletion or Arg-337 and Lys-338 mutations abrogated PSGL-1-induced ERK activation, whereas they did not prevent Syk phosphorylation or E-selectin-induced leukocyte slow rolling. These studies demonstrate that PSGL-1 EBS plays a critical role in recruiting leukocytes on selectins and in activating the MAPK pathway, whereas it is dispensable to phosphorylate Syk and to lead to α(L)β(2)-dependent leukocyte slow rolling.

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The current study conceptualized observer reactions to uncivil behavior towards women as an ethical behavior and examined three factors (target reaction, actor motive, and actor-target relationship) that influence these reactions. Two vignette studies with women and men undergraduate and graduate students in western Switzerland were conducted. Study 1 (N=148) was a written vignette study that assessed how the reaction of female targets to incivility and the motives of actors influenced observer reactions. Results showed that a female target's reaction influenced observers' evaluations of the harm caused by an uncivil incident, and that an actor's motive affected observers' assessments of the necessity to intervene. Study 2 (N=81) was a video vignette study that assessed the effects of the reactions by female targets to incivility and the relationship between the target and the actor on observer reactions.We found that female targets' reactions influenced observers' evaluations of harm and the perceived necessity to intervene. Furthermore, the effect of a female target's reaction on observers' evaluations of harm was moderated by the relationship between the actor and the target: a female target who laughed at the uncivil behavior was perceived as less harmed, when she and the actor had a personal relationship than when they had a professional relationship. When the female target reacted hurt or neutrally, actor-target relationship did not affect observers' evaluations of harm. We conclude by discussing the implications of our findings for theory and practice.

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PURPOSE: Ipilimumab is a monoclonal antibody that blocks the immune-inhibitory interaction between CTL antigen 4 (CTLA-4) and its ligands on T cells. Clinical trials in cancer patients with ipilimumab have shown promising antitumor activity, particularly in patients with advanced melanoma. Often, tumor regressions in these patients are correlated with immune-related side effects such as dermatitis, enterocolitis, and hypophysitis. Although these reactions are believed to be immune-mediated, the antigenic targets for the cellular or humoral immune response are not known. EXPERIMENTAL DESIGN: We enrolled patients with advanced melanoma in a phase II study with ipilimumab. One of these patients experienced a complete remission of his tumor. The specificity and functional properties of CD8-positive T cells in his peripheral blood, in regressing tumor tissue, and at the site of an immune-mediated skin rash were investigated. RESULTS: Regressing tumor tissue was infiltrated with CD8-positive T cells, a high proportion of which were specific for Melan-A. The skin rash was similarly infiltrated with Melan-A-specific CD8-positive T cells, and a dramatic (>30-fold) increase in Melan-A-specific CD8-positive T cells was apparent in peripheral blood. These cells had an effector phenotype and lysed Melan-A-expressing tumor cells. CONCLUSIONS: Our results show that Melan-A may be a major target for both the autoimmune and antitumor reactions in patients treated with anti-CTLA-4, and describe for the first time the antigen specificity of CD8-positive T cells that mediate tumor rejection in a patient undergoing treatment with an anti-CTLA-4 antibody. These findings may allow a better integration of ipilimumab into other forms of immunotherapy.

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Quintessence: L'impact du dépistage sur la mortalité du cancer du sein est avéré. Il baisse, indépendamment de la qualité du dépistage, en raison des importants progrès thérapeutiques des 20 dernières années.Les programmes de dépistage ont contribué à sensibiliser à la détection précoce, à améliorer la qualité de la mammographie et la prise en charge du cancer mammaire. Ces bénéfices s'étendent au-delà du dépistage et conduisent à sous-estimer l'effet du dépistage sur la mortalité.Les risques et les bénéfices du dépistage sont plus complexes à quantifier dans les programmes que dans les essais randomisés ; le recours à des méthodes appropriées et rigoureuses est nécessaire.Les faux-positifs et le surdiagnostic liés au dépistage n'ont pas diminué, augmentant le rapport risque/bénéfice de la mammographie.