982 resultados para cyclin-dependent kinases
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An in vitro model, the aggregating brain cell culture of fetal rat telencephalon, has been used to study the maturation-dependent sensitivity of brain cells to two organophosphorus pesticides (OPs), chlorpyrifos and parathion, and to their oxon derivatives. Immature (DIV 5-15) or differentiated (DIV 25-35) brain cells were treated continuously for 10 days. Acetylcholinesterase (AChE) inhibitory potency for the OPs was compared to that of eserine (physostigmine), a reversible AChE inhibitor. Oxon derivatives were more potent AChE inhibitors than the parent compounds, and parathion was more potent than chlorpyrifos. No maturation-dependent differences for AChE inhibition were found for chlorpyrifos and eserine, whereas for parathion and paraoxon there was a tendency to be more effective in immature cultures, while the opposite was true for chlorpyrifos-oxon. Toxic effects, assessed by measuring protein content as an index of general cytotoxicity, and various enzyme activities as cell-type-specific neuronal and glial markers (ChAT and GAD, for cholinergic and GABAergic neurons, respectively, and GS and CNP, for astrocytes and oligodendrocytes, respectively) were only found at more than 70% of AChE inhibition. Immature compared to differentiated cholinergic neurons appeared to be more sensitive to OP treatments. The oxon derivates were found to be more toxic on neurons than the parent compounds, and chlorpyrifos was more toxic than parathion. Eserine was not neurotoxic. These results indicate that inhibition of AChE remains the most sensitive macromolecular target of OP exposure, since toxic effects were found at concentrations in which AChE was inhibited. Furthermore, the compound-specific reactions, the differential pattern of toxicity of OPs compared to eserine, and the higher sensitivity of immature brain cells suggest that the toxic effects and inhibition of AChE are unrelated.
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Abstract OBJECTIVE To identify the factors associated with involuntary hospital admissions of technology-dependent children, in the municipality of Ribeirão Preto, São Paulo State, Brazil. METHOD A cross-sectional study, with a quantitative approach. After an active search, 124 children who qualified under the inclusion criteria, that is to say, children from birth to age 12, were identified. Data was collected in home visits to mothers or the people responsible for the children, through the application of a questionnaire. Analysis of the data followed the assumptions of the Generalized Linear Models technique. RESULTS 102 technology-dependent children aged between 6 months and 12 years participated in the study, of whom 57% were male. The average number of involuntary hospital admissions in the previous year among the children studied was 0.71 (±1.29). In the final model the following variables were significantly associated with the outcome: age (OR=0.991; CI95%=0.985-0.997), and the number of devices (OR=0.387; CI95%=0.219-0.684), which were characterized as factors of protection and quantity of medications (OR=1.532; CI95%=1.297-1.810), representing a risk factor for involuntary hospital admissions in technology-dependent children. CONCLUSION The results constitute input data for consideration of the process of care for technology-dependent children by supplying an explanatory model for involuntary hospital admissions for this client group.
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Food allergy in children significantly affects their quality of life. Its impact can be analyzed by quality of life questionnaires. The aim of our study was to validate the French version of disease-specific questionnaires and to evaluate the quality of life in children with IgE-mediated food allergy. Two validated food allergy-specific questionnaires for quality of life, the parent's and children's forms (FAQLQ-PF and FAQLQ-CF), were translated from English to French and submitted to children with food allergy and their parents. Questionnaires were analyzed in terms of emotional impact, food anxiety, and social and food limitations. NCT 01480427. Sixty-two parents of children aged 0-12 yrs answered the FAQLQ-PF, and 32 children aged 8-12 yrs the FAQLQ-CF. Construct validity of both questionnaires was assessed by correlation between the FAQLQs and FAIM (r = 0.85 and 0.84, respectively). Both FAQLQs had good internal consistency (Cronbach's α = 0.748 and 0.67, respectively). Young children (0-3 yrs old) showed better quality of life scores than older children (FAQLQ-PF global score: p = 0.02). Worse scores were also shown among children with previous severe systemic reactions (FAQLQ-PF global score: p = 0.039), the ones with an allergic mother (FAQLQ-PF global score: p = 0.002), or allergic siblings (FAQLQ-PF emotional impact score: p = 0.034), the ones with multiple food allergy (more than 1 food) (FAQLQ-PF anxiety score: p = 0.04) and among the girls (FAQLQ-CF global score: p = 0.031). Older children, the ones with severe systemic reactions, or with mothers or siblings also affected by allergies, as well as girls, and children with multiple food allergies show worse quality of life scores.
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Two distinct, TATA box-containing promoters regulate the transcriptional activity of the Xenopus vitellogenin A1 gene. These two promoters are of different strength and are separated by 1.8 kilobase pairs of untranslated sequence. Estrogen receptor (ER) and its ligand, 17beta-estradiol, induce the activity of both promoters. The estrogen response elements (EREs) are located proximal to the downstream i promoter while no ERE-like sequences have been identified in the vicinity of the upstream io promoter. We show here, that transcriptional activity of the upstream io promoter is Sp1-dependent. Moreover, we demonstrate that estrogen inducibility of the io promoter results from functional interactions between the io bound Sp1 and the ER bound at the proximity of i. Functional interactions between Sp1 and ER do not require the presence of a TATA box for transcriptional activation, as is demonstrated using the acyl-CoA oxidase promoter. The relative positions that ER and Sp1 occupy with respect to the initiation site determines whether these two transcription activators can synergize for transcription initiation.
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OBJECTIVE: In addition to its haemodynamic effects, angiotensin II (AngII) is thought to contribute to the development of cardiac hypertrophy via its growth factor properties. The activation of mitogen-activated protein kinases (MAPK) is crucial for stimulating cardiac growth. Therefore, the present study aimed to determine whether the trophic effects of AngII and the AngII-induced haemodynamic load were associated with specific cardiac MAPK pathways during the development of hypertrophy. Methods The activation of the extracellular-signal-regulated kinase (ERK), the c-jun N-terminal kinase (JNK) and the p38 kinase was followed in the heart of normotensive and hypertensive transgenic mice with AngII-mediated cardiac hypertrophy. Secondly, we used physiological models of AngII-dependent and AngII-independent renovascular hypertension to study the activation of cardiac MAPK pathways during the development of hypertrophy. RESULTS: In normotensive transgenic animals with AngII-induced cardiac hypertrophy, p38 activation is associated with the development of hypertrophy while ERK and JNK are modestly stimulated. In hypertensive transgenic mice, further activation of ERK and JNK is observed. Moreover, in the AngII-independent model of renovascular hypertension and cardiac hypertrophy, p38 is not activated while ERK and JNK are strongly stimulated. In contrast, in the AngII-dependent model, all three kinases are stimulated. CONCLUSIONS: These data suggest that p38 activation is preferentially associated with the direct effects of AngII on cardiac cells, whereas stimulation of ERK and JNK occurs in association with AngII-induced mechanical stress.
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We establish the validity of subsampling confidence intervals for themean of a dependent series with heavy-tailed marginal distributions.Using point process theory, we study both linear and nonlinear GARCH-liketime series models. We propose a data-dependent method for the optimalblock size selection and investigate its performance by means of asimulation study.
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Two populations of the wasp Trypoxylon rogenhoferi Kohl, 1884 from São Carlos and Luís Antônio, State of São Paulo, Brazil, were observed and sampled from May 1999 to February 2001 using trap-nests. This mass-provisioning wasp was used to test some aspects of optimal sex allocation theory. Both populations fit all the predictions of the models of Green and Brockmann and Grafen. Maternal provisions determined the size of each offspring, and females allocated well-stocked brood cells to daughters, the sex that benefits most being large. This strategy resulted in a difference in size between the sexes. In São Carlos, female weight at emergence was 1.18 times that of males, in Luís Antônio this value was 1.13. The brood cell volume was correlated with both wing length and weight at emergence in both sexes, and the chance that a given brood cell contained a male offspring decreased with increased brood cell volume. In T. rogenhoferi female body size was related to fitness. Larger females were able to collect more mass of spiders per day, the spiders they captured were heavier, and they provisioned more brood cells per day. They also produced larger daughters. For males, no relationship between body size and fitness was found, but the data were scarce. Since the patterns of provisioning were variable among different females in both study sites, it is possible that the females not follow a unique strategy for sex allocation. The sex ratio and/or investment ratio in the São Carlos population was female-biased and in Luís Antônio, male-biased. In spite of the influence of trap-nests diameters on male production in Luís Antônio, there is some evidence that in São Carlos population the local availability of prey and/or lower rate of parasitism may be major forces in determining the observed sex ratio, but further studies are necessary to verify such hypothesis.
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Nine forums were held across the state to continue the ongoing dialogue with professionals and stakeholders about how the service delivery and protection system for dependent adults and elders is functioning. Opinions were sought on what was working well, what could work better and their suggestions for improvements and/or changes at the local and state level.
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In todays competitive markets, the importance of goodscheduling strategies in manufacturing companies lead to theneed of developing efficient methods to solve complexscheduling problems.In this paper, we studied two production scheduling problemswith sequence-dependent setups times. The setup times areone of the most common complications in scheduling problems,and are usually associated with cleaning operations andchanging tools and shapes in machines.The first problem considered is a single-machine schedulingwith release dates, sequence-dependent setup times anddelivery times. The performance measure is the maximumlateness.The second problem is a job-shop scheduling problem withsequence-dependent setup times where the objective is tominimize the makespan.We present several priority dispatching rules for bothproblems, followed by a study of their performance. Finally,conclusions and directions of future research are presented.
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This paper analyses the effect of unmet formal care needs on informal caregiving hours in Spain using the two wavesof the Informal Support Survey (1994, 2004). Testing for double sample selection from formal care receipt and theemergence of unmet needs provides evidence that the omission of either variable would causes underestimation of thenumber of informal caregiving hours. After controlling for these two factors the number of hours of care increaseswith both the degree of dependency and unmet needs. More importantly, in the presence of unmet needs, the numberof informal caregiving hours increases when some formal care is received. This result refutes the substitution modeland supports complementarity or task specificity between both types of care. For a given combination of formal careand unmet needs, informal caregiving hours increased between 1994 and 2004. Finally, in the model for 2004, theselection term associated with the unmet needs equation is larger than that of the formal care equation, suggestingthat using the number of formal care recipients as a quality indicator may be confounding, if we do not complete thisinformation with other quality indicators.
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Human cytosolic thymidine kinase (hTK1) has proven to be a suitable target for the noninvasive imaging of cancer cell proliferation using radiolabeled thymidine analogues such as [(18)F]3'-fluoro-3'-deoxythymidine ([(18)F]FLT). A thymidine analogue for single photon emission computed tomography (SPECT), which incorporates the readily available and inexpensive nuclide technetium-99m, would be of considerable practical interest. hTK1 is known to accommodate modification of the structure of the natural substrate thymidine at the positions N3 and C3' and, to a lesser extent, C5. In this work, we used the copper-catalyzed azide-alkyne cycloaddition to synthesize two series of derivatives in which thymidine is functionalized at either the C3' or N3 position with chelating systems suitable for the M(CO)(3) core (M = (99m)Tc, Re). The click chemistry approach enabled complexes with different structures and overall charges to be synthesized from a common precursor. Using this strategy, the first organometallic hTK1 substrates in which thymidine is modified at the C3' position were identified. Phosphorylation of the organometallic derivatives was measured relative to thymidine. We have shown that the influence of the overall charge of the derivatives is dependent on the position of functionalization. In the case of the C3'-functionalized derivatives, neutral and anionic substrates were most readily phosphorylated (20-28% of the value for the parent ligand thymidine), whereas for the N3-functionalized derivatives, cationic and neutral complexes were apparently better substrates for the enzyme (14-18%) than anionic derivatives (9%).
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BACKGROUND: In contrast to wild type, interleukin-10-deficient (IL-10(-/-)) mice are able to clear Helicobacter infection. In this study, we investigated the immune response of IL-10(-/-) mice leading to the reduction of Helicobacter infection. MATERIALS AND METHODS: We characterized the immune responses of Helicobacter felis-infected IL-10(-/-) mice by studying the systemic antibody and cellular responses toward Helicobacter. We investigated the role of CD4(+) T cells in the Helicobacter clearance by injecting H. felis-infected IL-10(-/-) mice with anti-CD4 depleting antibodies. To examine the role of mast cells in Helicobacter clearance, we constructed and infected mast cells and IL-10 double-deficient mice. RESULTS: Reduction of Helicobacter infection in IL-10(-/-) mice is associated with strong humoral (fivefold higher serum antiurease antibody titers were measured in IL-10(-/-) in comparison to wild-type mice, p < .008) and cellular (urease-stimulated splenic CD4(+) T cells isolated from infected IL-10(-/-) mice produce 150-fold more interferon-gamma in comparison to wild-type counterparts, p < .008) immune responses directed toward Helicobacter. Depletion of CD4(+) cells from Helicobacter-infected IL-10(-/-) mice lead to the loss of bacterial clearance (rapid urease tests are threefold higher in CD4(+) depleted IL-10(-/-) in comparison to nondepleted IL-10(-/-) mice, p < .02). Mast cell IL-10(-/-) double-deficient mice clear H. felis infection, indicating that mast cells are unnecessary for the bacterial eradication in IL-10(-/-) mice. CONCLUSION: Taken together, these results suggest that CD4(+) cells are required for Helicobacter clearance in IL-10(-/-) mice. This reduction of Helicobacter infection is, however, not dependent on the mast cell population.
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The AP-1 family transcription factor ATF2 is essential for development and tissue maintenance in mammals. In particular, ATF2 is highly expressed and activated in the brain and previous studies using mouse knockouts have confirmed its requirement in the cerebellum as well as in vestibular sense organs. Here we present the analysis of the requirement for ATF2 in CNS development in mouse embryos, specifically in the brainstem. We discovered that neuron-specific inactivation of ATF2 leads to significant loss of motoneurons of the hypoglossal, abducens and facial nuclei. While the generation of ATF2 mutant motoneurons appears normal during early development, they undergo caspase-dependent and independent cell death during later embryonic and foetal stages. The loss of these motoneurons correlates with increased levels of stress activated MAP kinases, JNK and p38, as well as aberrant accumulation of phosphorylated neurofilament proteins, NF-H and NF-M, known substrates for these kinases. This, together with other neuropathological phenotypes, including aberrant vacuolisation and lipid accumulation, indicates that deficiency in ATF2 leads to neurodegeneration of subsets of somatic and visceral motoneurons of the brainstem. It also confirms that ATF2 has a critical role in limiting the activities of stress kinases JNK and p38 which are potent inducers of cell death in the CNS.
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Molecular mechanisms by which exercise exerts cardiovascular benefits are poorly understood. Exercise-induced increase of endothelial NO synthase (eNOS) phosphorylation through the protein kinase Akt has been shown to be a key mechanism underlying the beneficial effect of exercise in coronary artery disease patients. We examined whether this protective pathway might also be activated in long-term-exercised healthy mice. C57BL/6 wild-type mice swam for 24 weeks. A group of sedentary animals were used as controls. Aortic levels of total protein kinase Akt (protein kinase B), phosphorylated Akt at ser473 (p-Akt), total eNOS, phosphorylated eNOS at Ser1177 (p-eNOS), and PECAM-1 (platelet endothelial cell adhesion molecule-1) were assessed by Western blotting. Protein expressions of Akt, p-Akt, eNOS, p-eNOS, and PECAM-1 were not modulated by 24 weeks of exercise. The Akt-dependent eNOS phosphorylation did not seem to be a primary molecular adaptation in response to long-term exercise in healthy mice.