999 resultados para Early reactions


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Early Cretaceous life and the environment were strongly influenced by the accelerated break up of Pangaea, which was associated with the formation of a multitude of rift basins, intensified spreading, and important volcanic activity on land and in the sea. These processes likely interacted with greenhouse conditions, and Early Cretaceous climate oscillated between "normal" greenhouse, predominantly arid conditions, and intensified greenhouse, predominantly humid conditions. Arid conditions were important during the latest Jurassic and early Berriasian, the late Barremian, and partly also during the late Aptian. Humid conditions were particularly intense and widespread during shorter episodes of environmental change (EECs): the Valanginian Weissert, the latest Hauterivian Faraoni, the latest Barremian earliest Aptian Taxy, the early Aptian Selli, the early late Aptian Fallot and the late Aptian-early Albian Paquier episodes. Arid conditions were associated with evaporation, low biogeochemical weathering rates, low nutrient fluxes, and partly stratified oceans, leading to oxygen depletion and enhanced preservation of laminated, organic-rich mud (LOM). Humid conditions enabled elevated biogeochemical weathering rates and nutrient fluxes, important runoff and the buildup of freshwater lids in proximal basins, intensified oceanic and atmospheric circulation, widespread upwelling and phosphogenesis, important primary productivity and enhanced preservation of LOM in expanded oxygen-minimum zones. The transition of arid to humid climates may have been associated with the net transfer of water to the continent owing to the infill of dried-out groundwater reservoirs in internally drained inland basins. This resulted in shorter-term sea-level fall, which was followed by sea-level rise. These sea-level changes and the influx of freshwater into the ocean may have influenced oxygen-isotope signatures. Climate change preceding and during the Early Cretaceous EECs may have been rapid, but in general, the EECs had a "pre"-history, during which the stage was set for environmental change. Negative feedback on the climate through increased marine LOM preservation was unlikely, because of the low overall organic-carbon accumulation rates during these episodes. Life and climate co-evolved during the Early Cretaceous. Arid conditions may have affected continental life, such as across the Tithonian/Berriasian boundary. Humid conditions and the corresponding tendency to develop dys- to anaerobic conditions in deeper ocean waters led to phases of accelerated extinction in oceans, but may have led to more luxuriant vegetation cover on continents, such as during the Valanginian, to the benefit of herbivores. During Early Cretaceous EECs, reef systems and carbonate platforms in general were particularly vulnerable. They were the first to disappear and the last to recover, often only after several million years. (C) 2011 Elsevier Ltd. All rights reserved.

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Chagas disease, caused by the intracellular protozoan Trypanosoma cruzi, is a serious health problem in Latin America. During this parasitic infection, the heart is one of the major organs affected. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. When cells are infected with T. cruzi, they develop an inflammatory response, in which cyclooxygenase-2 (COX-2) catalyses rate-limiting steps in the arachidonic acid pathway. However, how the parasite interaction modulates COX-2 activity is poorly understood. In this study, the H9c2 cell line was used as our model and we investigated cellular and biochemical aspects during the initial 48 h of parasitic infection. Oscillatory activity of COX-2 was observed, which correlated with the control of the pro-inflammatory environment in infected cells. Interestingly, subcellular trafficking was also verified, correlated with the control of Cox-2 mRNA or the activated COX-2 protein in cells, which is directly connected with the assemble of stress granules structures. Our collective findings suggest that in the very early stage of the T. cruzi-host cell interaction, the parasite is able to modulate the cellular metabolism in order to survives.

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Hypohidrosis is a classic feature of Fabry disease; in contrast, hyperhidrosis has only been rarely described. The aim of the study is to characterise the baseline descriptive data on hyperhidrosis (frequency, age at onset, sex ratio and outcome with and without enzyme replacement therapy) in hemizygous male and heterozygous female patients with Fabry disease. We describe case histories of five patients with Fabry disease and hyperhidrosis seen at three different centres. We have also analysed a cohort of 21 paediatric patients in the UK and a large European cohort of patients enrolled in the Fabry Outcome Survey (FOS). Five patients (three female, two male) with hyperhidrosis were originally identified, although each had additional symptoms related to Fabry disease. The age at onset of hyperhidrosis was less than 18 years in four cases. In the cohort of 21 paediatric patients (12 female, nine male), one female had hyperhidrosis; the age at onset of this symptom was 11 years. In the FOS cohort, 66 of 714 patients with Fabry disease had hyperhidrosis (44 of 369 females, 11.9%; 22 of 345 males, 6.4%). The female predominance was observed in seven of nine countries from which data were analysed. Hyperhidrosis is an increasingly recognised feature of the Fabry disease phenotype. It is more prevalent in females than in males and often appears in childhood or adolescence. The efficacy of enzyme replacement therapy on this recently recognised symptom should be assessed.

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Leprosy inflammatory episodes [type 1 (T1R) and type 2 (T2R) reactions] represent the major cause of irreversible nerve damage. Leprosy serology is known to be influenced by the patient’s bacterial index (BI) with higher positivity in multibacillary patients (MB) and specific multidrug therapy (MDT) reduces antibody production. This study evaluated by ELISA antibody responses to leprosy Infectious Disease Research Institute diagnostic-1 (LID-1) fusion protein and phenolic glycolipid I (PGL-I) in 100 paired serum samples of 50 MB patients collected in the presence/absence of reactions and in nonreactional patients before/after MDT. Patients who presented T2R had a median BI of 3+, while MB patients with T1R and nonreactional patients had median BI of 2.5+ (p > 0.05). Anti-LID-1 and anti-PGL-I antibodies declined in patients diagnosed during T1R (p < 0.05). Anti-LID-1 levels waned in MB with T2R at diagnosis and nonreactional MB patients (p < 0.05). Higher anti-LID-1 levels were seen in patients with T2R at diagnosis (vs. patients with T1R at diagnosis, p = 0.008; vs. nonreactional patients, p = 0.020) and in patients with T2R during MDT (vs. nonreactional MB, p = 0.020). In MB patients, high and persistent anti-LID-1 antibody levels might be a useful tool for clinicians to predict which patients are more susceptible to develop leprosy T2R.

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While early intervention strategies have been developed for psychotic disorders, affective psychoses and bipolar disorders have been neglected by this movement. However, when considering that outcome of bipolar disorders is often not as favorable as previously thought and that delay between illness onset and introduction of an adequate treatment is often very long, such developments seem clearly justified. In this paper we briefly review arguments supporting early intervention in bipolar disorders, the practical and theoretical obstacles that still need to be overcome, the strategies that may already now contribute to decrease treatment delay, and we describe current state of research regarding identification of the prodromal phase of bipolar disorders.

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Les changements environnementaux, tels la température ou les maladies infectieuses, peuvent influencer l'évolution en induisant de la sélection, mais ceci à la seule condition qu'il y ait assez de diversité génétique pour les traits en question ou pour l'expression plastique de ces traits. Au cours cette thèse, nous avons étudié l'effet de potentielles pressions environnementales sur différents phénotypes de trois représentants des sous familles des salmonidés: l'ombre commun (Thymallus thymallus; Thymallinae), la truite de rivière {Salmo trutta; Salmoninae) et le corégone Coregonus palaea (Coregoninae). Les salmonidés se prêtent particulièrement bien à ce type d'expériences car étant hautement sensibles aux conditions environnementales, ils montrent une large variabilité dans leurs traits morphologiques, comportementaux ainsi que d'histoire de vie, tout en bénéficiant d'un large intérêt général. Nous avons testé si le sexe de l'ombre commun pouvait être modifié par la température, ce qui pourrait ainsi expliquer un changement abrupte de sex ratio observé dans l'une des plus grandes populations de Suisse. Nous n'avons trouvé aucun indice permettant de conclure que la température puisse induire ce changement chez l'ombre commun ou chez la truite de rivière. De plus nous avons étudié la plasticité de développement ainsi que d'éclosion, et avons observé des différences entre familles ainsi qu'entre populations. Alors que ces différences comportementales entre populations suggéraient une adaptation aux conditions environnementales locales, cette prédiction n'a pas été confirmée par une expérience de transplantation réciproque d'embryons entre cinq rivières de la même région. Cette étude a montré que les embryons ne survivaient pas mieux dans leur rivière d'origine, indiquant donc une absence d'adaptation locale. Nous avons aussi montré que la mortalité embryonnaire était influencée autant par des "bons gènes" que par des "gènes compatibles", que la qualité des mâles pouvait être signalée par leur coloration, et que le fait d'élever des poissons dans une pisciculture pouvait aboutir a des relations contre-intuitives entre la coloration des mâles et la qualité de leur jeunes. Nos résultats contribuent ainsi à une meilleure compréhension de l'effet de diverses pressions environnementales sur la morphologie, le comportement ou les traits d'histoire de vie chez les salmonidés. - Environmental changes, such as changes in temperatures or infection levels, can induce selection and drive evolution if there is sufficient genetic variation for the traits or the plasticity in trait expression. In this thesis, we investigated the influence of potential environmental stressors on various phenotypes in representatives of the three salmonid subfamilies: the European grayling (Thymallus thymallus; Thymallinae), the brown trout (,Salmo trutta; Salmoninae), and the whitefish Coregonus palaea (Coregoninae). Salmonids are ideal study species, as they seem sensitive to changing environmental conditions, show considerable variability in morphological, behavioral, and life history traits, and are of broad public interest. We investigated whether temperature-induced sex reversal could explain the sex-ratio distortion found in one of Switzerland's largest grayling populations. We found no evidence of temperature-induced sex reversal in either graylings or brown trout. We also examined plasticity in embryo development and the timing of hatching. We found variation at the level of family and population. Although behavioral differences between populations suggested adaptation to local environmental conditions, no indications of local adaptation could be found in reciprocal transplant experiments carried out over five rivers in the same region. We also demonstrate that embryo development and viability is influenced by 'good genes' and 'compatible genes', that the genetic quality of sires can be signaled by their grey coloration, and that raising larvae in a hatchery environment can produce counter-intuitive relationships between male phenotypes and offspring viability. Our results contribute to the understanding of how changing environmental conditions affect the phenotypes and the heritability of early life-history traits in salmonids.

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Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

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Allergy to nonsteroidal antiinflammatory drugs (NSAIDs) is a very common affliction, especially among patients with asthma and chronic urticaria. These reactions are most often of a non-immunological nature but related to pharmacologic intolerance and linked to arachidonic acid metabolism and leukotriene release. Therefore, crossed reactions implying all non-selective and semi-selective NSAIDs constitute the rule, especially during respiratory reactions to NSAIDs and for patients with chronic urticaria. In isolated acute urticaria, crossed reactions are difficult to predict so caution is necessary. Tolerance induction is possible, especially when aspirin has to be administered in small doses as antiplatelet agent. Finally, acetaminophen and selective NSAIDs as celecoxib are well tolerated by most of these patients. L'allergie aux anti-inflammatoires non stéroïdiens (AINS) est très fréquente, en particulier chez les asthmatiques ou dans l'urticaire chronique. Il s'agit en général de réactions non immunologiques, mais dues à une intolérance pharmacologique liée au métabolisme de l'acide arachidonique et à la formation de leucotriènes. Ainsi, les réactions croisées impliquant tous les AINS non sélectifs et semi-sélectifs sont la règle, surtout lors de réactions respiratoires aux AINS et dans l'urticaire chronique. Lors d'urticaire aiguë isolée, les réactions croisées sont difficiles à prédire, ainsi la prudence s'impose. Une induction de tolérance est possible, en particulier lorsque l'aspirine est nécessaire à dose faible, comme antiagrégant plaquettaire. Enfin, le paracétamol et les AINS sélectifs sont supportés par la grande majorité de ces patients.

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Lobectomy via video-assisted thoracoscopic surgery (VATS) is now considered as a valid alternative to conventional thoracotomy for early-stage primary lung cancer. Various studies have reported that VATS lobectomy is a safe technique associated with fewer postoperative complications and better post-operative recovery than open thoracotomy. Furthermore, studies suggest oncological equivalence between VATS and open lobectomy.

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Cancer testis antigens (CTAs) are expressed in a variety of malignant tumors but not in any normal adult tissues except germ cells and occasionally placenta. Because of this tumor-associated pattern of expression, CTAs are regarded as potential vaccine targets. The expression of CTAs in gastrointestinal stromal tumors (GIST) has not been analyzed systematically previously. The present study was performed to analyze the expression of CTA in GIST and to determine if CTA expression correlates with prognosis. Thirty-five GIST patients were retrospectively analyzed for their expression of CTAs by immunohistochemistry using the following monoclonal antibodies (mAb/antigen): MA454/MAGE-A1, M3H67/MAGE-A3, 57B/MAGE-A4, CT7-33/MAGE-C1 and E978/NY-ESO-1. Fourteen tumors (40%) expressed 1 or more of the 5 CTAs tested. Fourteen percent (n = 5/35) were positive for MAGE-A1, MAGE-A3 or MAGE-A4, respectively. Twenty-six percent (n = 9/35) stained positive for MAGE-C1 and 20% (n = 7/35) for NY-ESO-1. A highly significant correlation between CTA expression and tumor recurrence risk was observed (71% vs. 29%; p = 0.027). In our study population, the high-risk GIST expressed CTAs more frequently than low-risk GIST (p = 0.012). High-risk GISTs which stained positive for at least 1 CTA, recurred in 100% (n = 25) of the cases. This is the first study analyzing CTA expression in GIST and its prognostic value for recurrence. The CTA staining could add information to the individual patient prognosis and represent an interesting target for future treatment strategies.

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During the Early Toarcian, major paleoenvironnemental and paleoceanographical changes occurred, leading to an oceanic anoxic event (OAE) and to a perturbation of the carbon isotope cycle. Although the standard biochronology of the Lower Jurassic is essentially based upon ammonites, in recent years biostratigraphy based on calcareous nannofossils and dinoflagellate cysts is increasingly used to date Jurassic rocks. However, the precise dating and correlation of the Early Toarcian OAE, and of the associated delta C-13 anomaly in different settings of the western Tethys, are still partly problematic, and it is still unclear whether these events are synchronous or not. In order to allow more accurate correlations of the organic rich levels recorded in the Lower Toarcian OAE, this account proposes a new biozonation based on a quantitative biochronology approach, the Unitary Associations (UA), applied to calcareous nannofossils. This study represents the first attempt to apply the UA method to Jurassic nannofossils. The study incorporates eighteen sections distributed across western Tethys and ranging from the Pliensbachian to Aalenian, comprising 1220 samples and 72 calcareous nannofossil taxa. The BioGraph [Savary, J., Guex, J., 1999. Discrete biochronological scales and unitary associations: description of the Biograph Computer program. Memoires de Geologie de Lausanne 34, 282 pp] and UA-Graph (Copyright Hammer O., Guex and Savary, 2002) softwares provide a discrete biochronological framework based upon multi-taxa concurrent range zones in the different sections. The optimized dataset generates nine UAs using the co-occurrences of 56 taxa. These UAs are grouped into six Unitary Association Zones (UA-Z), which constitute a robust biostratigraphic synthesis of all the observed or deduced biostratigraphic relationships between the analysed taxa. The UA zonation proposed here is compared to ``classic'' calcareous nannofossil biozonations, which are commonly used for the southern and the northern sides of Tethys. The biostratigraphic resolution of the UA-Zones varies from one nannofossil subzone or part of it to several subzones, and can be related to the pattern of calcareous nannoplankton originations and extinctions during the studied time interval. The Late Pliensbachian - Early Toarcian interval (corresponding to the UA-Z II) represents a major step in the Jurassic nannoplankton radiation. The recognized UA-Zones are also compared to the carbon isotopic negative excursion and TOC maximum in five sections of central Italy, Germany and England, with the aim of providing a more reliable correlation tool for the Early Toarcian OAE, and of the associated isotopic anomaly, between the southern and northern part of western Tethys. The results of this work show that the TOC maximum and delta C-13 negative excursion correspond to the upper part of the UA-Z II (i.e., UA 3) in the sections analysed. This suggests that the Early Toarcian OAE was a synchronous event within the western Tethys. (c) 2006 Elsevier B.V. All rights reserved.