974 resultados para ANTI-PGL-I
Resumo:
Cooperation in joint enterprises can easily break down when self-interests are in conflict with collective benefits, causing a tragedy of the commons. In such social dilemmas, the possibility for contributors to invest in a common pool-rewards fund, which will be shared exclusively among contributors, can be powerful for averting the tragedy, as long as the second-order dilemma (i.e. withdrawing contribution to reward funds) can be overcome (e.g. with second-order sanctions). However, the present paper reveals the vulnerability of such pool-rewarding mechanisms to the presence of reward funds raised by defectors and shared among them (i.e. anti-social rewarding), as it causes a cooperation breakdown, even when second-order sanctions are possible. I demonstrate that escaping this social trap requires the additional condition that coalitions of defectors fare poorly compared with pro-socials, with either (i) better rewarding abilities for the latter or (ii) reward funds that are contingent upon the public good produced beforehand, allowing groups of contributors to invest more in reward funds than groups of defectors. These results suggest that the establishment of cooperation through a collective positive incentive mechanism is highly vulnerable to anti-social rewarding and requires additional countermeasures to act in combination with second-order sanctions.
Resumo:
Passive immunization against β-amyloid (Aβ) has become an increasingly desirable strategy as a therapeutic treatment for Alzheimer's disease (AD). However, traditional passive immunization approaches carry the risk of Fcγ receptor-mediated overactivation of microglial cells, which may contribute to an inappropriate proinflammatory response leading to vasogenic edema and cerebral microhemorrhage. Here, we describe the generation of a humanized anti-Aβ monoclonal antibody of an IgG4 isotype, known as MABT5102A (MABT). An IgG4 subclass was selected to reduce the risk of Fcγ receptor-mediated overactivation of microglia. MABT bound with high affinity to multiple forms of Aβ, protected against Aβ1-42 oligomer-induced cytotoxicity, and increased uptake of neurotoxic Aβ oligomers by microglia. Furthermore, MABT-mediated amyloid plaque removal was demonstrated using in vivo live imaging in hAPP((V717I))/PS1 transgenic mice. When compared with a human IgG1 wild-type subclass, containing the same antigen-binding variable domains and with equal binding to Aβ, MABT showed reduced activation of stress-activated p38MAPK (p38 mitogen-activated protein kinase) in microglia and induced less release of the proinflammatory cytokine TNFα. We propose that a humanized IgG4 anti-Aβ antibody that takes advantage of a unique Aβ binding profile, while also possessing reduced effector function, may provide a safer therapeutic alternative for passive immunotherapy for AD. Data from a phase I clinical trial testing MABT is consistent with this hypothesis, showing no signs of vasogenic edema, even in ApoE4 carriers.
Resumo:
Human inhibitor NF-κB kinase 2 (hIKK-2) is the primary component responsible for activating NF-κB in response to various inflammatory stimuli. Thus, synthetic ATP-competitive inhibitors for hIKK-2 have been developed as anti-inflammatory compounds. We recently reported a virtual screening protocol (doi:10.1371/journal.pone.0016903) that is able to identify hIKK-2 inhibitors that are not structurally related to any known molecule that inhibits hIKK-2 and that have never been reported to have anti-inflammatory activity. In this study, a stricter version of this protocol was applied to an in-house database of 29,779 natural products annotated with their natural source. The search identified 274 molecules (isolated from 453 different natural extracts) predicted to inhibit hIKK-2. An exhaustive bibliographic search revealed that anti-inflammatory activity has been previously described for: (a) 36 out of these 453 extracts; and (b) 17 out of 30 virtual screening hits present in these 36 extracts. Only one of the remaining 13 hit molecules in these extracts shows chemical similarity with known synthetic hIKK-2 inhibitors. Therefore, it is plausible that a significant portion of the remaining 12 hit molecules are lead-hopping candidates for the development of new hIKK-2 inhibitors.
Resumo:
Se han caracterizado químicamente diferentes tipos de vidrios arquitectónicos originales de la iglesia del Monestir de Pedralbes, Barcelona (realizados hacia 1330). Esta nota expone los resultados obtenidos mediante el empleo de microsonda electrónica en vidrios de varios colores (blanco, verde, rosado, azul, amarillo, rojo) de la vidriera de Sant Pere y Sant Jaume. Corresponden esencialmente a vidrios sódicos (dentro del rango 13-19 % de Na2O) de coloración y composición homogénea, con elementos que actúan como colorante (p.e., CuO en rango 1.6-6 % en los vidrios verdes). El vidrio rojo, potásico, es una excepción notable (16.5 % K2O, 14 % CaO), tecnológicamente diferente (vidrio"plaqué" blanco con una intercalación roja de composición análoga pero sensiblemente más rica en CuO). Los vidrios sódicos no aparecen substancialmente dañados, los vidrios potásicos presentan corrosiones (moderadas) y pérdida parcial de transparencia. El predominio en esta vidriera de vidrios sódicos (inusuales para la época por lo que conocemos) ha permitido una excelente conservación. La composición química es una característica que permite diagnosticar precozmente el estado de deterioro y evaluar los costes de restauración en una vidriera, independientemente de los recubrimientos, pátinas y morteros que ésta presente.
Resumo:
The molecular chaperone Hsp90-dependent proteome represents a complex protein network of critical biological and medical relevance. Known to associate with proteins with a broad variety of functions termed clients, Hsp90 maintains key essential and oncogenic signalling pathways. Consequently, Hsp90 inhibitors are being tested as anti-cancer drugs. Using an integrated systematic approach to analyse the effects of Hsp90 inhibition in T-cells, we quantified differential changes in the Hsp90-dependent proteome, Hsp90 interactome, and a selection of the transcriptome. Kinetic behaviours in the Hsp90-dependent proteome were assessed using a novel pulse-chase strategy (Fierro-Monti et al., accompanying article), detecting effects on both protein stability and synthesis. Global and specific dynamic impacts, including proteostatic responses, are due to direct inhibition of Hsp90 as well as indirect effects. As a result, a decrease was detected in most proteins that changed their levels, including known Hsp90 clients. Most likely, consequences of the role of Hsp90 in gene expression determined a global reduction in net de novo protein synthesis. This decrease appeared to be greater in magnitude than a concomitantly observed global increase in protein decay rates. Several novel putative Hsp90 clients were validated, and interestingly, protein families with critical functions, particularly the Hsp90 family and cofactors themselves as well as protein kinases, displayed strongly increased decay rates due to Hsp90 inhibitor treatment. Remarkably, an upsurge in survival pathways, involving molecular chaperones and several oncoproteins, and decreased levels of some tumour suppressors, have implications for anti-cancer therapy with Hsp90 inhibitors. The diversity of global effects may represent a paradigm of mechanisms that are operating to shield cells from proteotoxic stress, by promoting pro-survival and anti-proliferative functions. Data are available via ProteomeXchange with identifier PXD000537.
Resumo:
It has been shown previously that CD8beta in vitro increases the range and the sensitivity of antigen recognition and in vivo plays an important role in the thymic selection of CD8+ T cells. Consistent with this, we report here that CD8+ T cells from CD8beta knockout (KO) P14 TCR transgenic mice proliferate inefficiently in vitro. In contrast to these findings, we also show that CD8beta KO mice mount normal CD8 primary, secondary and memory responses to acute infection with lymphocytic choriomeningitis virus. Tetramer staining and cytotoxic experiments revealed a predominance of CD8-independent CTL in CD8beta KO mice. The TCR repertoire, especially the one of the TCRalpha chain, was different in CD8beta KO mice as compared with B6 mice. Our results indicate that in the absence of CD8beta, CD8-independent TCRs are preferentially selected, which in vivo effectively compensates for the reduced co-receptor function of CD8alphaalpha.
Resumo:
Introduction. - Le traitement de la polymyosite et de l'atteinte pulmonaireassociées au syndrome des anti-synthétases peut serévéler difficile. Le tacrolimus est proposé en cas d'échec aux autresimmunosuppresseurs. Néanmoins, contrairement aux patientsgreffés, son utilisation dans cette indication est mal codifiée. Nousrapportons les cas de 2 patients traités efficacement par tacrolimus.Cas Clinique. - Cas 1. Il s'agit d'un homme de 44 ans originaire deMadagascar, chez qui le diagnostic de syndrome des anti-synthétasesest posé devant l'association mains de mécanicien, polymyosite,manifestation de raynaud et présence d'anticorps anti Jo1fortement positifs à 281U (norme < 50U). Les différents traitementsproposés (prednisone 1 mg/kg, méthotrexate, azathioprine,rituximab et Immunoglobulines IV) ne permettent pas de contrôlerla situation avec un pic des CK à 24 000 U/l au décours des Ig IV.Une IRM réalisée alors retrouve une activité inflammatoire intensedes compartiments antérieurs et postérieurs des cuisses des 2 côtés.Finalement un traitement de tacrolimus est proposé en augmentationprogressive. L'efficacité du traitement est mesurée par l'évolutiondes CK qui passent en quelques mois de 24 000 U/l à 300 U/lsous une dose de 6 mg/j de tacrolimus et d'une amélioration parIRM spectaculaire. Malheureusement, suite à un épisode de déshydratation,le patient développe une insuffisance rénale aigüemodérée (créatinine à 124 _mol/l contre 89 auparavant) non réversibleaprès réhydratation. Pour stabiliser la fonction rénale le tacrolimusest baissé à 4 mg/jour au prix d'une réapparition des douleursmusculaires et d'une ré-ascension des CK à 1 000 U/l. Cas 2. Il s'agitd'une patiente de 61 ans chez qui le diagnostic de syndrome desanti-synthétases est posé devant l'association atteinte articulaire,mains de mécanicien, atteinte musculaire, pneumopathie interstitiellediffuse et forte positivité des Ac anti JO1 à 252 U. Une associationtacrolimus et prednisone est rapidement proposée en raison del'atteinte pulmonaire. Malheureusement la patiente développe uneinsuffisance rénale progressive sous 9 mg/j de tacrolimus et malgréune réponse favorable sur le plan pulmonaire, le traitement estinterrompu avec amélioration de la fonction rénale.Discussion. - Le tacrolimus est un traitement immunosuppresseuranalogue à la ciclosporine, avec une action 100 fois supérieure. Ilinhibe l'activation et la prolifération des cellules T et sa principaletoxicité est rénale. Traitement puissant, il a montré son efficacitédans les atteintes pulmonaires sévères liées à un syndrome desanti-synthétases1.2. Les pneumologues le connaissent bien et chezles patients greffés, la surveillance de l'efficacité et de la toxicité dutraitement se fait grâce à des mesures du taux résiduel. Néanmoinsdans le cadre du syndrome des anti-synthétases les mesures de surveillancesont moins bien codifiées. Même si l'efficacité du tacrolimussemble excellente dans les formes musculaires etpulmonaires sévères, nos 2 cas nous rendent attentifs sur l'importanced'une surveillance rapprochée de la fonction rénale.Conclusion. - Le tacrolimus est un puissant immunosuppresseur quipeut être proposé aux patients souffrant de manifestations sévèresd'un syndrome des anti-synthétases. Une dose standard n'existe paset il faut être attentif à sa toxicité rénale.
Resumo:
Paclitaxel (Tx)-loaded anti-HER2 immunonanoparticles (NPs-Tx-HER) were prepared by the covalent coupling of humanized monoclonal anti-HER2 antibodies (trastuzumab, Herceptin) to Tx-loaded poly (dl-lactic acid) nanoparticles (NPs-Tx) for the active targeting of tumor cells that overexpress HER2 receptors. The physico-chemical properties of NPs-Tx-HER were compared to unloaded immunonanoparticles (NPs-HER) to assess the influence of the drug on anti-HER2 coupling to the NP surface. The immunoreactivity of sulfo-MBS activated anti-HER2 mAbs and the in vitro efficacy of NPs-Tx-HER were tested on SKOV-3 ovarian cancer cells that overexpress HER2 antigens. Tx-loaded nanoparticles (NPs-Tx) obtained by a salting-out method had a size of 171+/-22 nm (P.I.=0.1) and an encapsulation efficiency of about of 78+/-10%, which corresponded to a drug loading of 7.8+/-0.8% (w/w). NPs-Tx were then thiolated and conjugated to activated anti-HER2 mAbs to obtain immunonanoparticles of 237+/-43 nm (P.I.=0.2). The influence of the activation step on the immunoreactivity of the mAbs was tested on SKOV-3 cells using 125I-radiolabeled mAbs, and the activity of the anti-HER2 mAbs was minimally affected after sulfo-MBS functionalization. Approximately 270 molecules of anti-HER2 mAbs were bound per nanoparticle. NPs-Tx-HER exhibited a zeta potential of 0.2+/-0.1 mV. The physico-chemical properties of the Tx-loaded immunonanoparticles were very similar to unloaded immunonanoparticles, suggesting that the encapsulation of the drug did not influence the coupling of the mAbs to the NPs. No drug loss was observed during the preparation process. DSC analysis showed that encapsulated Tx is in an amorphous or disordered-crystalline phase. These results suggest that Tx is entrapped in the polymeric matrix and not adsorbed to the surface of the NPs. In vitro studies on SKOV-3 ovarian cancer cells demonstrated the greater cytotoxic effect of NPs-Tx-HER compared to other Tx formulations. The results showed that at 1 ng Tx/ml, the viability of cells incubated with drug encapsulated in NP-Tx-HER was lower (77.32+/-5.48%) than the viability of cells incubated in NPs-Tx (97.4+/-12%), immunonanoparticles coated with Mabthera, as irrelevant mAb (NPs-Tx-RIT) (93.8+/-12%) or free drug (92.3+/-9.3%).
Resumo:
Recent studies have shown that melanin-based coloration is associated with the ability to cope with stressful environments, potentially explaining why coloration covaries with anti-predator behaviours, boldness and docility. To investigate whether these relationships are consistent across species, we performed a study in the European kestrel (Falco tinnunculus). Similar to our results found previously in the barn owl (Tyto alba), nestling kestrels displaying a larger sub-terminal black tail band stayed on their back longer (tonic immobility test) and breathed at a lower rate than individuals with a smaller black band when handled. However, in contrast to barn owls, nestling kestrels with a larger black tail band were more aggressive and more agitated. Our results strengthen the hypothesis that melanin coloration is related to stress response and in turn to the reaction to predators, a very important personality trait (i.e. boldness).
Resumo:
The general strategy to perform anti-doping analyses of urine samples starts with the screening for a wide range of compounds. This step should be fast, generic and able to detect any sample that may contain a prohibited substance while avoiding false negatives and reducing false positive results. The experiments presented in this work were based on ultra-high-pressure liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry. Thanks to the high sensitivity of the method, urine samples could be diluted 2-fold prior to injection. One hundred and three forbidden substances from various classes (such as stimulants, diuretics, narcotics, anti-estrogens) were analysed on a C(18) reversed-phase column in two gradients of 9min (including two 3min equilibration periods) for positive and negative electrospray ionisation and detected in the MS full scan mode. The automatic identification of analytes was based on retention time and mass accuracy, with an automated tool for peak picking. The method was validated according to the International Standard for Laboratories described in the World Anti-Doping Code and was selective enough to comply with the World Anti-Doping Agency recommendations. In addition, the matrix effect on MS response was measured on all investigated analytes spiked in urine samples. The limits of detection ranged from 1 to 500ng/mL, allowing the identification of all tested compounds in urine. When a sample was reported positive during the screening, a fast additional pre-confirmatory step was performed to reduce the number of confirmatory analyses.
Resumo:
We have previously reported that the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β) induce profound modifications of the metabolic profile of astrocytes. The present study was undertaken to further characterize the effects of cytokines in astrocytes and to determine whether similar effects could also be observed in neurons. To do so, selected pro-inflammatory (IL-6 and interferon-γ, in addition to the above-mentioned TNFα and IL-1β) and anti-inflammatory cytokines (IL-4, IL-10, transforming growth factor-β1 and interferon-β) were applied to primary neuronal and astrocytic cultures, and key metabolic parameters were assessed. As a general pattern, we observed that pro-inflammatory cytokines increased glucose utilization in astrocytes while the anti-inflammatory cytokines IL-4 and IL-10 decreased astrocytic glucose utilization. In contrast, no significant change could be observed in neurons. When pairs of pro-inflammatory cytokines were co-applied in astrocytes, several additive or synergistic modifications could be observed. In contrast, IL-10 partially attenuated the effects of pro-inflammatory cytokines. Finally, the modifications of the astrocytic metabolism induced by TNFα + IL-1β and interferon-γ modulated neuronal susceptibility to an excitotoxic insult in neuron-astrocyte co-cultures. Together, these results suggest that pro- and anti-inflammatory cytokines differentially affect the metabolic profile of astrocytes, and that these changes have functional consequences for surrounding neurons.
Resumo:
S100A4, a member of the S100 calcium-binding protein family secreted by tumor and stromal cells, supports tumorigenesis by stimulating angiogenesis. We demonstrated that S100A4 synergizes with vascular endothelial growth factor (VEGF), via the RAGE receptor, in promoting endothelial cell migration by increasing KDR expression and MMP-9 activity. In vivo overexpression of S100A4 led to a significant increase in tumor growth and vascularization in a human melanoma xenograft M21 model. Conversely, when silencing S100A4 by shRNA technology, a dramatic decrease in tumor development of the pancreatic MiaPACA-2 cell line was observed. Based on these results we developed 5C3, a neutralizing monoclonal antibody against S100A4. This antibody abolished endothelial cell migration, tumor growth and angiogenesis in immunodeficient mouse xenograft models of MiaPACA-2 and M21-S100A4 cells. It is concluded that extracellular S100A4 inhibition is an attractive approach for the treatment of human cancer.
Resumo:
The use of chemicals is a critical part of a pro-active winter maintenance program. However, ensuring that the correct chemicals are used is a challenge. On the one hand, budgets are limited, and thus price of chemicals is a major concern. On the other, performance of chemicals, especially at lower pavement temperatures, is not always assured. Two chemicals that are used extensively by the Iowa Department of Transportation (Iowa DOT) are sodium chloride (or salt) and calcium chloride. While calcium chloride can be effective at much lower temperatures than salt, it is also considerably more expensive. Costs for a gallon of salt brine are typically in the range of $0.05 to $0.10, whereas calcium chloride brine may cost in the range of $1.00 or more per gallon. These costs are of course subject to market forces and will thus change from year to year. The idea of mixing different winter maintenance chemicals is by no means new, and in general discussions it appears that many winter maintenance personnel have from time to time mixed up a jar of chemicals and done some work around the yard to see whether or not their new mix “works.” There are many stories about the mixture turning to “mayonnaise” (or, more colorfully, to “snot”) suggesting that mixing chemicals may give rise to some problems most likely due to precipitation. Further, the question of what constitutes a mixture “working” in this context is a topic of considerable discussion. In this study, mixtures of salt brine and calcium chloride brine were examined to determine their ice melting capability and their freezing point. Using the results from these tests, a linear interpolation model of the ice melting capability of mixtures of the two brines has been developed. Using a criterion based upon the ability of the mixture to melt a certain thickness of ice or snow (expressed as a thickness of melt-water equivalent), the model was extended to develop a material cost per lane mile for the full range of possible mixtures as a function of temperature. This allowed for a comparison of the performance of the various mixtures. From the point of view of melting capacity, mixing calcium chloride brine with salt brine appears to be effective only at very low temperatures (around 0° F and below). However, the approach described herein only considers the material costs, and does not consider application costs or other aspects of the mixture performance than melting capacity. While a unit quantity of calcium chloride is considerably more expensive than a unit quantity of sodium chloride, it also melts considerably more ice. In other words, to achieve the same result, much less calcium chloride brine is required than sodium chloride brine. This is important in considering application costs, because it means that a single application vehicle (for example, a brine dispensing trailer towed behind a snowplow) can cover many more lane miles with calcium chloride brine than with salt brine before needing to refill. Calculating exactly how much could be saved in application costs requires an optimization of routes used in the application of liquids in anti-icing, which is beyond the scope of the current study. However, this may be an area that agencies wish to pursue for future investigation. In discussion with winter maintenance personnel who use mixtures of sodium chloride and calcium chloride, it is evident that one reason for this is because the mixture is much more persistent (i.e. it stays longer on the road surface) than straight salt brine. Operationally this persistence is very valuable, but at present there are not any established methods to measure the persistence of a chemical on a pavement. In conclusion, the study presents a method that allows an agency to determine the material costs of using various mixtures of salt brine and calcium chloride brine. The method is based upon the requirement of melting a certain quantity of snow or ice at the ice-pavement interface, and on how much of a chemical or of a mixture of chemicals is required to do that.
Resumo:
O objetivo deste trabalho foi avaliar a ação imunoesterilizadora de uma vacina anti-hormônio liberador de hormônio luteinizante (LHRH), composta por ovalbumina-LHRH-7 e tiorredoxina-LHRH-7, em touros mestiços Nelore. Vinte e seis touros, com dois anos de idade, foram distribuídos aleatoriamente em dois grupos de 13 animais. No grupo I, os animais receberam uma dose e dois reforços da vacina nos dias 0, 141, e 287 do experimento. No grupo II, os animais não receberam nenhum tratamento (controle). Para avaliar o efeito da vacina nos touros, foi realizada a mensuração da circunferência escrotal no início do experimento e no dia do abate, 741 dias depois. Por ocasião do abate, também foi coletada uma amostra dos testículos para avaliação histológica. O grupo imunizado apresentou circunferência escrotal ao abate de 22±5,98 cm, menor do que a do grupo controle que foi de 35,6±2,4 cm. Na análise histológica dos animais do grupo imunizado, foi observada degeneração testicular com ausência de espermatozoides em 85% dos animais avaliados, os outros 15% apresentaram redução no número de espermatozoides, em comparação aos animais do grupo controle. A vacina anti-LHRH, com fusão de proteínas, é efetiva na castração imunológica de touros e deve ser considerada como alternativa para utilização na produção bovina extensiva no Brasil.