123 resultados para 2004-02-BS
Resumo:
Macrophage cholesterol homeostasis is a key process involved in the initiation and progression of atherosclerosis. Peroxisome proliferator-activated receptors (PPARs) regulate the transcription of the genes involved in cholesterol homeostasis and thus represent an important therapeutic target in terms of reducing atherosclerosis. Conjugated linoleic acid (CLA) is a potent anti-atherogenic dietary fatty acid in animal models of atherosclerosis and is capable of activating PPARs in vitro and in vivo. Therefore, this study examined whether the anti-atherogenic effects of CLA in vivo could be ascribed to altered cholesterol homeostasis in macrophages and macrophage derived foam cells. Of several genes that regulate cholesterol homeostasis investigated, CLA had most effect on the class B scavenger receptor CD36. The cis-9,trans-11 CLA (c9,t11-CLA) and trans-10,cis-12 CLA (t10,c12-CLA) isomers augmented CD36 mRNA expression (P
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A new ternary Ir-Mn-Si phase with stoichiometry Mn3IrSi has been synthesized and found to crystallize in the cubic AlAu4-type structure, space group P213 with Z=4, which is an ordered form of the beta-Mn structure. The unit cell dimension was determined by x-ray powder diffraction to a=6.4973(3) Angstrom. In addition to the crystal structure, we have determined the magnetic structure and properties using superconducting quantum interference device magnetometry and Rietveld refinements of neutron powder diffraction data. A complex noncollinear magnetic structure is found, with magnetic moments of 2.97(4)u(B) at 10 K only on the Mn atoms. The crystal structure consists of a triangular network built up by Mn atoms, on which the moments are rotated 120degrees around the triangle axes. The magnetic unit cell is the same as the crystallographic and carries no net magnetic moment. The Neel temperature was determined to be 210 K. A first-principles study, based on density functional theory in a general noncollinear formulation, reproduces the experimental results with good agreement. The observed magnetic structure is argued to be the result of frustration of antiferromagnetic couplings by the triangular geometry.
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Carbon-14 wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between 14C age and calendar age to match the shape of a series of closely spaced peat 14C dates with the 14C calibration curve. The method of WMD is discussed, and its advantages and limitations are compared with calibration of individual dates. A numerical approach to WMD is introduced that makes it possible to assess the precision of WMD chronologies. During several intervals of the Holocene, the 14C calibration curve shows less pronounced fluctuations. We assess whether wiggle-matching is also a feasible strategy for these parts of the 14C calibration curve. High-precision chronologies, such as obtainable with WMD, are needed for studies of rapid climate changes and their possible causes during the Holocene.
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In this paper an evaluation approach to assess the co-ordination of supportive community cancer care is presented. The aim of the study was to identify current gaps in co-ordination of services in a selected region in the province of Ontario, Canada, determine how consistent these gaps were across the province of Ontario, and develop service design considerations for improving the co-ordination of supportive cancer care services in the province of Ontario. The study addressed services required by two populations - clients who had been recently diagnosed and those in the palliative stages of cancer. The evaluation was theory-driven and incorporated evidence from three methods: a systematic literature review, a community case study and a provincial scan. The results revealed the absence of a formal supportive cancer care system and a complex community care system. Supportive cancer care was shown to be delivered by a range of generalist programs that lacked specialisation in addressing the unique needs of cancer clients. In addition, there was no clear evidence of leadership for co-ordinating supportive cancer care, where client care was most often provided by multiple programs at any given point in time. The study generated recommendations to improve co-ordination of supportive cancer care at both the administrative as well as direct care level. © 2004 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Purpose To quantify autofluorescence (AF) levels in patients with Stargardt macular dystrophy-fundus flavimaculatus (STGD-FFM), and to identify patterns of AF. Design Observational, comparative study. Methods Prospective study. Settings Patients were recruited at Moorfields Eye Hospital. Study population Forty-three STGD-FFM patients aged 20 to 40 years and 35 age-matched normal volunteers. The right eye was chosen arbitrarily for measures of AF. Intervention The AF images were obtained using a confocal scanning laser ophthalmoscope. Levels of AF across the macula were measured. The distribution of AF was also evaluated. In 36 patients (84%) pattern electroretinogram (PERG) and full-field ERG were obtained and results were evaluated with respect to levels of AF. Main outcome measures Values of AF, AF distribution, PERG, and ERG. Results Normal or high AF at the center of the macula with high AF temporally or nasally or both was detected in 17 patients (39%). In nine (21%), low AF at the center of the macula with normal or low AF temporally or nasally or both was found. Levels of AF were normal throughout the macula in six patients (14%). In 11 (26%), high, normal, and low levels of AF were found. All patients tested with low AF at the center of the macula and normal or low AF temporally or nasally or both had peripheral cone/rod dysfunction. None of the patients tested that had normal or high AF at the fovea and high AF temporally or nasally, or normal AF throughout the macula, had peripheral cone/rod dysfunction. Conclusion AF is not universally high in STGD-FFM. Some patients have normal or low AF. Autofluorescence patterns appear to relate to functional abnormalities. © 2004 by Elsevier Inc. All rights reserved.
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Research has consistently shown that family caregivers have a variety of unmet needs, despite comprehensive professional support for caregivers being a central aim of palliative care. This sub-study of a larger randomized controlled trial sought feedback from 47 primary family caregivers of advanced cancer patients who had recently commenced home palliative care. During semi-structured interviews in their homes, family caregivers were asked to comment on the key challenges associated with their role and whether they could identify challenges. These were associated with their own ill health, family circumstances, insufficient skills to manage patient symptoms, limited time for themselves and inadequate support from health professionals. Despite these challenges, 60% of family caregivers were readily able to identify positive aspects of the role. Previous research has tended to focus on the negative impact of caregiving. The extent to which the positive aspects buffer the negative aspects of the role warrants further exploration, as does the long-term impact of the caregiver role on those who are unable to recognize positive elements.
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Caring for a dying relative is demanding, and family caregivers have acknowledged many unmet needs associated with their caregiver role. Consistently, caregivers of dying patients with cancer have reported that they need more support and information from health care professionals. Moreover, a number of palliative care clinicians and researchers have called for interventions to enhance the support offered to family caregivers. However, before researchers can develop and test palliative care interventions directed to families, it is important to identify barriers that may confront health care professionals with regard to the provision of supportive family care. For new interventions to be feasible they must be applicable within the constraints of current palliative care service delivery environments. This paper provides an account of issues that may impinge on optimal transference of supportive strategies from health care professionals to family caregivers of patients receiving palliative care. By acknowledging these barriers to supportive care, researchers and health care professionals can begin to design and implement interventions that are clinically relevant and more likely to be effective.
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Plant embryogenesis is intimately associated with programmed cell death. The mechanisms of initiation and control of programmed cell death during plant embryo development are not known. Proteolytic activity associated with caspase-like proteins is paramount for control of programmed cell death in animals and yeasts. Caspase family of proteases has unique strong preference for cleavage of the target proteins next to asparagine residue. In this work, we have used synthetic peptide substrates containing caspase recognition sites and corresponding specific inhibitors to analyse the role of caspase-like activity in the regulation of programmed cell death during plant embryogenesis. We demonstrate that VEIDase is a principal caspase-like activity implicated in plant embryogenesis. This activity increases at the early stages of embryo development that coincide with massive cell death during shape remodeling. The VEIDase activity exhibits high sensitivity to pH, ionic strength and Zn2+ concentration. Altogether, biochemical assays show that VEIDase plant caspase-like activity resembles that of both mammalian caspase-6 and yeast metacaspase, YCA1. In vivo, VEIDase activity is localised specifically in the embryonic cells during both the commitment and in the beginning of the execution phase of programmed cell death. Inhibition of VEIDase prevents normal embryo development via blocking the embryo-suspensor differentiation. Our data indicate that the VEIDase activity is an integral part in the control of plant developmental cell death programme, and that this activity is essential for the embryo pattern formation.
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This paper reports the first observation, using in situ FTIR spectroscopy, of the oxidation of CO adsorbates on the Ru(0001) electrode to CO under open circuit (oc) conditions in both perchloric acid and sulphuric acid solution at 20 and 55 °C. While the significant oc oxidation of the adsorbed CO on the Ru(0001) electrode was observed in perchloric acid solution, much less oc oxidation took place in sulfuric acid solution due to the specific adsorption of bisulfate at the Ru surface which inhibits the surface oxidation and reduces the reactivity of the surface towards the oxidation of CO . The oc oxidation of the CO depends strongly on the oxygen concentration in the solution and the temperature. The data so obtained are compared to those observed at the gas|solid interface, as well as to those obtained from the electro-oxidation of CO , and possible new catalytic oxidation reaction mechanisms are discussed. In addition, it is shown that the C-O frequency of the adsorbed CO may be used as an effective probe of the open circuit potential. © 2003 Elsevier B.V. All rights reserved.
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Schizophrenia is clinically heterogeneous and multidimensional, but it is not known whether this is due to etiological heterogeneity. Previous studies have not consistently reported association between any specific polymorphisms and clinical features of schizophrenia, and have primarily used case-control designs. We tested for the presence of association between clinical features and polymorphisms in the genes for the serotonin 2A receptor (HT2A), dopamine receptor types 2 and 4, dopamine transporter (SLC6A3), and brain-derived neurotrophic factor (BDNF). Two hundred seventy pedigrees were ascertained on the basis of having two or more members with schizophrenia or poor outcome schizoaffective disorder. Diagnoses were made using a structured interview based on the SCID. All patients were rated on the major symptoms of schizophrenia scale (MSSS), integrating clinical and course features throughout the course of illness. Factor analysis revealed positive, negative, and affective symptom factors. The program QTDT was used to implement a family-based test of association for quantitative traits, controlling for age and sex. We found suggestive evidence of association between the His452Tyr polymorphism in HT2A and affective symptoms (P = 0.02), the 172-bp allele of BDNF and negative symptoms (P = 0.04), and the 480-bp allele in SLC6A3 (= DAT1) and negative symptoms (P = 0.04). As total of 19 alleles were tested, we cannot rule out false positives. However, given prior evidence of involvement of the proteins encoded by these genes in psychopathology, our results suggest that more attention should be focused on the impact of these alleles on clinical features of schizophrenia.
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Question. How many deaths were attributable to smoking in 2000 worldwide? Study design. Statistical extrapolation of epidemiological and clinical data. Main results. In the year 2000, about 12% of adults died prematurely from smoking (estimated 4.83 million uncertainty range 3.94-5.93 million). Leading causes of death attributable to smoking were cardiovascular diseases (1.69 million deaths), chronic obstructive pulmonary disease (0.97 million deaths) and lung cancer (0.85 million deaths; 71% of lung cancers were smoking related). Smoking related deaths in men were about 3 times more common than women in industrial countries, and about 7 times more common in developing countries. Authors' conclusions. Smoking was a major cause of death worldwide in 2000. © 2004 Elsevier Ltd. All rights reserved.
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There is little understanding in ecology as to how biodiversity patterns emerge from the distribution patterns of individual species. Here we consider the question of the contributions of rare (restricted range) and common (widespread) species to richness patterns. Considering a species richness pattern, is most of the spatial structure, in terms of where the peaks and troughs of diversity lie, caused by the common species or the rare species (or neither)? Using southern African and British bird richness patterns, we show here that commoner species are most responsible for richness patterns. While rare and common species show markedly different species richness patterns, most spatial patterning in richness is caused by relatively few, more common, species. The level of redundancy we found suggests that a broad understanding of what determines the majority of spatial variation in biodiversity may be had by considering only a minority of species.
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The process involves encapsulation or immobilization of the active solid substance in a cellulose framework by regenerating cellulose dissolved in an ionic liq. solvent in a regenerating soln. The active substance can be initially present in the ionic liq. or in the regenerating solvent either as a soln. or dispersion. The invention is applicable to mol. encapsulation and to entrapping of larger particles including enzymes, nanoparticles and macroscopic components, and to the formation of bulk materials with a wide range of morphol. forms. Thus, carbamoylmethylphosphine oxide (I) encapsulated in a cellulose matrix was realized by adding I to a 10% soln. of cellulose in 1-butyl-3-methylimidazolium chloride (ionic liq.) under vigorous stirring and then removing the ionic liq. with water. [on SciFinder(R)]