Showing papers by "State University of Campinas published in 2007"

Loss-of-Function Mutation in Toll-Like Receptor 4 Prevents Diet-Induced Obesity and Insulin Resistance

Abstract: Obesity is associated with insulin resistance and a state of abnormal inflammatory response. The Toll-like receptor (TLR)4 has an important role in inflammation and immunity, and its expression has been reported in most tissues of the body, including the insulin-sensitive ones. Because it is activated by lipopolysaccharide and saturated fatty acids, which are inducers of insulin resistance, TLR4 may be a candidate for participation in the cross-talk between inflammatory and metabolic signals. Here, we show that C3H/HeJ mice, which have a loss-of-function mutation in TLR4, are protected against the development of diet-induced obesity. In addition, these mice demonstrate decreased adiposity, increased oxygen consumption, a decreased respiratory exchange ratio, improved insulin sensitivity, and enhanced insulin-signaling capacity in adipose tissue, muscle, and liver compared with control mice during high-fat feeding. Moreover, in these tissues, control mice fed a high-fat diet show an increase in IkappaB kinase complex and c-Jun NH(2)-terminal kinase activity, which is prevented in C3H/HeJ mice. In isolated muscles from C3H/HeJ mice, protection from saturated fatty acid-induced insulin resistance is observed. Thus, TLR4 appears to be an important mediator of obesity and insulin resistance and a potential target for the therapy of these highly prevalent medical conditions.

Correlation of the highest-energy cosmic rays with nearby extragalactic objects.

Abstract: Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above {approx} 6 x 10{sup 19} eV and the positions of active galactic nuclei (AGN) lying within {approx} 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.

Asparagine in plants

Abstract: Interest in plant asparagine has rapidly taken off over the past 5 years following the report that acrylamide, a neurotoxin and potential carcinogen, is present in cooked foods, particularly carbohydrate-rich foods such as wheat and potatoes which are subjected to roasting, baking or frying at high temperatures. Subsequent studies showed that acrylamide could be formed in foods by the thermal degradation of free asparagine in the presence of sugars in the Maillard reaction. In this article, our current knowledge of asparagine in plants and in particular its occurrence in cereal seeds and potatoes is reviewed and discussed in relation to acrylamide formation. There is now clear evidence that soluble asparagine accumulates in most if not all plant organs during periods of low rates of protein synthesis and a plentiful supply of reduced nitrogen. The accumulation of asparagine occurs during normal physiological processes such as seed germination and nitrogen transport. However, in addition, stress-induced asparagine accumulation can be caused by mineral deficiencies, drought, salt, toxic metals and pathogen attack. The properties and gene regulation of the enzymes involved in asparagine synthesis and breakdown in plants are discussed in detail.

Habitat split and the global decline of amphibians

Abstract: The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely “habitat split”—defined as human-induced disconnection between habitats used by different life history stages of a species—which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

In vivo Preservation of the Hybrid Layer by Chlorhexidine

Abstract: Host-derived proteases have been reported to degrade the collagen matrix of incompletely-resin-infiltrated dentin. This study tested the hypothesis that interfacial degradation of resin-dentin bonds may be prevented or delayed by the application of chlorhexidine (CHX), a matrix metalloproteinase inhibitor, to dentin after phosphoric acid-etching. Contralateral pairs of resin-bonded Class I restorations in non-carious third molars were kept under intra-oral function for 14 months. Preservation of resin-dentin bonds was assessed by microtensile bond strength tests and TEM examination. In vivo bond strength remained stable in the CHX-treated specimens, while bond strength decreased significantly in control teeth. Resin-infiltrated dentin in CHX-treated specimens exhibited normal structural integrity of the collagen network. Conversely, progressive disintegration of the fibrillar network was identified in control specimens. Auto-degradation of collagen matrices can occur in resin-infiltrated dentin, but may be prevented by the application of a synthetic protease inhibitor, such as chlorhexidine.

Apoio matricial e equipe de referência: uma metodologia para gestão do trabalho interdisciplinar em saúde

Abstract: The authors discuss a theoretical and conceptual management methodology based on reference teams and matrix support. Reference team is a structural organization intended to combine managerial power and interdisciplinary work. Matrix support changes the way traditional health systems work, with specialists organically linked to other teams who periodically require specialized consultation. Besides care support, there is another goal: to build new knowledge for each health professional through a continuing education process. The article analyzes the structural, political, cultural, theoretical, and subjective obstacles to this new model.

Non-random coextinctions in phylogenetically structured mutualistic networks.

Abstract: Plants and their pollinators and seed dispersers form complex networks of interdependences. These networks have a well-defined architecture that strongly affects biodiversity maintenance. Using a phylogenetic approach, Rezende et al. show that past evolutionary history of plants and animals partly explains the network patterns. Closely related species tend to play similar roles in the network. As a result, coextinction cascades following a species extinction affect taxonomically related species, resulting in a non-random pruning of the evolutionary tree. From a conservation standpoint, this means that cascades of coextinction may spread across related species, further increasing the erosion of taxonomic diversity. A phylogenetic approach is used to show that past evolutionary history partly explains network patterns that link plants and their pollinators and seed dispersers. Species close in the phylogeny tend to play similar roles in the network. As a result, co-extinction cascades following the extinction of a species affect taxonomically related species, resulting in a non-random pruning of the evolutionary tree. The interactions between plants and their animal pollinators and seed dispersers have moulded much of Earth’s biodiversity1,2,3. Recently, it has been shown that these mutually beneficial interactions form complex networks with a well-defined architecture that may contribute to biodiversity persistence4,5,6,7,8. Little is known, however, about which ecological and evolutionary processes generate these network patterns3,9. Here we use phylogenetic methods10,11 to show that the phylogenetic relationships of species predict the number of interactions they exhibit in more than one-third of the networks, and the identity of the species with which they interact in about half of the networks. As a consequence of the phylogenetic effects on interaction patterns, simulated extinction events tend to trigger coextinction cascades of related species. This results in a non-random pruning of the evolutionary tree12,13 and a more pronounced loss of taxonomic diversity than expected in the absence of a phylogenetic signal. Our results emphasize how the simultaneous consideration of phylogenetic information and network architecture can contribute to our understanding of the structure and fate of species-rich communities.

Theory of neutrinos: a white paper

Abstract: This paper is a review of the present status of neutrino mass physics, which grew out of an APS sponsored study of neutrinos in 2004. After a discussion of the present knowledge of neutrino masses and mixing and some popular ways to probe the new physics implied by recent data, it summarizes what can be learned about neutrino interactions as well as the nature of new physics beyond the Standard Model from the various proposed neutrino experiments. The intriguing possibility that neutrino mass physics may be at the heart of our understanding of a long standing puzzle of cosmology, i.e. the origin of matter?antimatter asymmetry is also discussed.

Comparative support for the niche variation hypothesis that more generalized populations also are more heterogeneous

Abstract: There is extensive evidence that some species of ecological generalists, which use a wide diversity of resources, are in fact heterogeneous collections of relatively specialized individuals. This within-population variation, or "individual specialization," is a key requirement for frequency-dependent interactions that may drive a variety of types of evolutionary diversification and may influence the population dynamics and ecological interactions of species. Consequently, it is important to understand when individual specialization is likely to be strong or weak. The niche variation hypothesis (NVH) suggests that populations tend to become more generalized when they are released from interspecific competition. This niche expansion was proposed to arise via increased variation among individuals rather than increased individual niche breadth. Consequently, we expect ecological generalists to exhibit stronger individual specialization, but this correlation has been repeatedly rejected by empiricists. The drawback with previous empirical tests of the NVH is that they use morphological variation as a proxy for niche variation, ignoring the role of behavior and complex phenotype-function relationships. Here, we used diet data to directly estimate niche variation among individuals. Consistent with the NVH, we show that more generalized populations also exhibit more niche variation. This trend is quite general, appearing in all five case studies examined: three-spine stickleback, Eurasian perch, Anolis lizards, intertidal gastropods, and a community of neotropical frogs. Our results suggest that generalist populations may tend to be more ecologically variable. Whether this translates into greater genetic variation, evolvability, or ecological stability remains to be determined.

Chlorhexidine Preserves Dentin Bond in vitro

Abstract: Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted third molars were sectioned into two halves. One half was customarily restored (etch-and-rinse adhesive/resin composite), and the other was treated with 2% chlorhexidine after being acid-etched before restoration. Specimens were stored in artificial saliva with/without protease inhibitors. Microtensile bond strengths and failure mode distribution under SEM were analyzed immediately after specimens' preparation and 6 months later. With chlorhexidine, significantly better preservation of bond strength was observed after 6 months; protease inhibitors in the storage medium had no effect. Failure analysis showed significantly less failure in the hybrid layer with chlorhexidine, compared with controls after 6 months. In conclusion, this in vitro study suggests that chlorhexidine might be useful for the preservation of dentin bond strength.

Identification and Quantification of Carotenoids, By HPLC-PDA-MS/MS, from Amazonian Fruits

Abstract: The major and minor carotenoids from six fruits, buriti (Mauritia vinifera), mamey (Mammea americana), marimari (Geoffrola striata), peach palm (Bactrys gasipaes), physalis (Physalis angulata), and tucuma (Astrocaryum aculeatum), all native to the Amazonia region, were determined by high-performance liquid chromatography-photodiode array detector-mass spectrometry detector (HPLC-PDA-MS/MS), fulfilling the recommended criteria for identification. A total of 60 different carotenoids were separated on a C30 column, all-trans-beta-carotene being the major carotenoid found in all fruits. The presence of apo-10'-beta-carotenol, found in mamey, was not previously reported in foods. In addition, this is the first time that the identification of beta-zeacarotene in natural sources is supported by MS data. The total carotenoid content ranged from 38 microg/g in marimari to 514 microg/g in buriti. All fruits analyzed can be considered good sources of provitamin A, especially buriti, with 7280 RE/100 g.

Activated protein C protects against diabetic nephropathy by inhibiting endothelial and podocyte apoptosis

Abstract: Data providing direct evidence for a causative link between endothelial dysfunction, microvascular disease and diabetic end-organ damage are scarce. Here we show that activated protein C (APC) formation, which is regulated by endothelial thrombomodulin, is reduced in diabetic mice and causally linked to nephropathy. Thrombomodulin-dependent APC formation mediates cytoprotection in diabetic nephropathy by inhibiting glomerular apoptosis. APC prevents glucose-induced apoptosis in endothelial cells and podocytes, the cellular components of the glomerular filtration barrier. APC modulates the mitochondrial apoptosis pathway via the protease-activated receptor PAR-1 and the endothelial protein C receptor EPCR in glucose-stressed cells. These experiments establish a new pathway, in which hyperglycemia impairs endothelial thrombomodulin-dependent APC formation. Loss of thrombomodulin-dependent APC formation interrupts cross-talk between the vascular compartment and podocytes, causing glomerular apoptosis and diabetic nephropathy. Conversely, maintaining high APC levels during long-term diabetes protects against diabetic nephropathy.

Xp11 translocation renal cell carcinoma in adults: expanded clinical, pathologic, and genetic spectrum

Abstract: The recently recognized Xp11 translocation renal cell carcinomas (RCCs), all of which bear gene fusions involving the TFE3 transcription factor gene, comprise at least one-third of pediatric RCC. Only rare adult cases have been reported, without detailed pathologic analysis. We identified and analyzed 28 Xp11 translocation RCC in patients over the age of 20 years. All cases were confirmed by TFE3 immunohistochemistry, a sensitive and specific marker of neoplasms with TFE3 gene fusions, which can be applied to archival material. Three cases were also confirmed genetically. Patients ranged from ages 22 to 78 years, with a strong female predominance (F:M=22:6). These cancers tended to present at advanced stage; 14 of 28 presented at stage 4, whereas lymph nodes were involved by metastatic carcinoma in 11 of 13 cases in which they were resected. Previously not described and distinctive clinical presentations included dense tumor calcifications such that the tumor mimicked renal lithiasis, and obstruction of the renal pelvis promoting extensive obscuring xanthogranulomatous pyelonephritis. Previously unreported morphologic variants included tumor giant cells, fascicles of spindle cells, and a biphasic appearance that simulated the RCC characterized by a t(6;11)(p21;q12) chromosome translocation. One case harbored a novel variant translocation, t(X;3)(p11;q23). Five of 6 patients with 1 or more years of follow-up developed hematogenous metastases, with 2 dying within 1 year of diagnosis. Xp11 translocation RCC can occur in adults, and may be aggressive cancers that require morphologic distinction from clear cell and papillary RCC. Although they may be uncommon on a percentage basis, given the vast predominance of RCC in adults compared with children, adult Xp11 translocation RCC may well outnumber their pediatric counterparts.

OneMap: software for genetic mapping in outcrossing species

Abstract: OneMap is an environment for constructing linkage maps of outcrossing plant species, using full-sib families derived from two outbred parents. The analyses are performed using a novel methodology based on the maximum likelihood approach for simultaneous estimation of linkage and linkage phases (Wu et al. 2002), which has been successfully applied to sugarcane (Garcia et al. 2006). It is implemented as a set of functions for the freely distributed software R, and handles pairwise marker analysis, marker ordering and map refinement. The software is freely available at http://www.ciagri.usp.br/∼aafgarci/OneMap/.

From dry bonding to water-wet bonding to ethanol-wet bonding. A review of the interactions between dentin matrix and solvated resins using a macromodel of the hybrid layer.

Abstract: PURPOSE To review the use of a new resin-dentin bonding model called the macro-hybrid layer, to quantify resin uptake and matrix shrinkage during resin infiltration and solvent evaporation. A secondary purpose was to introduce the concept of ethanol-wet bonding where water-saturated acid-etched dentin is exchanged with ethanol to create ethanol-saturated dentin. Adhesive monomers seem to penetrate ethanol-saturated dentin more thoroughly than water-saturated dentin.

Second- and third-order multivariate calibration: data, algorithms and applications

Abstract: We review second- and third-order multivariate calibration, based on the growing literature in this field, the variety of data being produced by modern instruments, and the proliferation of algorithms capable of dealing with higher-order data. We primarily emphasize the relevance of the subject to analytical chemistry. We intend, in the terminology section, to clarify some confusing features relating to the definition of sample constituents in second-order calibration. We then classify and compare instrumental data and available algorithms. We provide insight into the relative advantages and disadvantages of the existing algorithms (e.g., in terms of: achieving second-order advantage (the ability to cope with varying amounts of potential interferents in test samples), presence of linear dependency in the data, handling trilinear deviations, using incomplete calibration data, extension to higher-order information, handling missing values; and, providing physico-chemical information. Finally, we present a number of applications, selected from recent second- and third-order experimental works based on data obtained through excitation-emission fluorescence spectroscopy, spectral-kinetic and spectral-pH measurements, and hyphenated techniques.

Atividade antioxidante de frutas do cerrado

Abstract: Annona crassiflora (araticum), Solanum lycocarpum (lobeira), Eugenia dysenterica (cagaita), Caryocar brasilense (pequi) and Swartzia langsdorfii (banha de galinha) are tropical fruits consumed mainly by native people in the Brazilian Cerrado (second biggest biome of Brazil). In this study, pulp, seed and peel of the fruits were extracted using ethanol and water. Some of the extracts showed a high content of total phenols and were screened for their potential as antioxidants using the in vitro model 2,2-diphenyl-1-picryl hydrazyl (DPPH). The best results were found for aqueous and ethanolic extracts of pequi peel (IC50 of 9,44 and 17,98 µg.mL-1 respectively), etanolic extract of cagaita seeds (IC50 of 14,15 µg.mL-1), etanolic extract of araticum seeds and peel (IC50 of 30,97 and 49,18 µg.mL-1 respectively). This is the first report on the antioxidant properties of the extracts of cerrado fruit fractions. Owing to these properties, studies can be further extended to use them for possible applications as natural antioxidant for cosmetics, supplements and functional ingredients for food products as well as being able to represent a sustainable application of the natural sources in the Brazilian bioma cerrado.

Laser Induced Breakdown Spectroscopy

Abstract: This review describes the fundamentals, instrumentation, applications and future trends of an analytical technique that is in its early stages of consolidation and is establishing its definitive niches among modern spectrometric techniques. The technique has been named Laser Induced Breakdown Spectroscopy (LIBS) and its main characteristic stands in the use of short laser pulses as the energy source to vaporize samples and excite the emission of electromagnetic radiation from its elements and/or molecular fragments. The emitted radiation is analyzed by high resolution optics and the intensities are recorded, usually by fast triggered solid state detectors. Together, these devices allow producing and registering a wide ranging emission spectrum of the short-lived phenomenon induced by the laser pulse. The spectrum contains qualitative and quantitative information which can be correlated with sample identity or can be used to determine the amount of its constituents. This review is divided in four parts. First, the relevant historical and theoretical concepts associated with LIBS are presented; then the main practical aspects of the several experimental and instrumental approaches employed for implementation of the technique are critically described; the applications related in the literature, including those making use of chemometrics, are classified and exemplified with relevant and recently published work. Finally, an attempt to portray an overall evaluation and future perspectives of the technique are presented.

Development of a Brazilian Portuguese version of the Oswestry Disability Index: cross-cultural adaptation, reliability, and validity.

Abstract: STUDY DESIGN: Translation, revision, back-translation, and 3-way validity were performed. OBJECTIVE: The objective of this study was to translate a version of the Oswestry Disability Index (ODI) into Brazilian Portuguese and evaluate its reliability. SUMMARY OF BACKGROUND DATA: Reports in the literature have identified a need for internationally standardized and reliable measurements to analyze back pain. The ODI has become one of the principal outcome measurements used in the management of spinal disorders. METHODS: The cross-cultural adaptation was performed according to the internationally recommended methodology, using the following guidelines: translation, back-translation; revision by a committee, and pretesting. The psychometric properties were evaluated by administering the questionnaire to 120 subjects with back pain. Reliability was estimated through stability and homogeneity assessment. The validity was tested comparing ODI scores with the following measurements: Roland-Morris Disability Questionnaire, SF-36, and a Numerical Pain Scale. RESULTS: Good internal consistency was found (Cronbach's alpha = 0.87). Intraclass correlation coefficient for test-retest reliability was 0.99. The ODI showed moderate correlation with pain measurement (r = 0.66). Relatively high correlation was also found between the ODI and the Roland-Morris scores (r = 0.81). There was significant correlation (P < 0.001) between ODI scores and the 8 scales of the SF-36. CONCLUSIONS: The data showed that the cultural adaptation process was successful and that the adapted instrument demonstrated having excellent psychometric properties, reliable in the Brazilian culture.

A systematic review of stress and psychological factors as possible risk factors for periodontal disease.

Abstract: Background Clinical observations and epidemiologic studies suggest that some negative life events and psychological factors may contribute to an increased susceptibility to periodontal disease. The aim of the present study was to systematically review the evidence from case-control studies, cross-sectional studies, and prospective clinical trials reporting on the influence of stress and psychological factors on periodontal disease. The focused question addressed in this systematic review was whether the scientific evidence is enough to consider stress and psychological factors as risk factors for periodontal disease. Methods A literature search was conducted using two databases (MEDLINE and the Cochrane Oral Health Group specialist trials register) in addition to searching reference lists of original and review articles. The search strategy used was the combination of the terms: "stress," "periodontal disease," and "psychosocial disorders." Studies were selected if they were published in dental journals between January 1, 1990 and April 1, 2006; only human studies and studies with adults and middle-aged subjects were included. Suitable variables included control for the potential effect of confounding factors, adequate criteria to define periodontal disease, adequate criteria for establishing stress, and methodologic quality. Only English-language articles were considered, and unpublished data were not sought. Two reviewers independently extracted information regarding quality and study characteristics in duplicate. The studies were assessed regarding their methodologic characteristics, statistical analysis, characteristics of the periodontal outcome measures, and psychological measurements. Results Of the 58 articles identified in the search, 10 were excluded because they were reviews and 34 did not comply with the selection criteria. Fourteen articles (seven case-control studies, six cross-sectional studies, and one prospective clinical trial) were included in the analysis; their quality and main study characteristics were assessed according to the criteria preestablished in the protocol of the study. With regard to the results of the studies, 57.1% found a positive outcome between psychosocial factors/stress and periodontal disease, 28.5% observed a positive outcome for some characteristics and a negative outcome for others, and 14.2% found a negative outcome. Conclusions Within the limitations of this systematic review, the majority of studies showed a positive relationship between stress/psychological factors and periodontal disease. However, in the future, well-designed and more representative studies should be considered to confirm these factors as a risk for periodontal disease.

A simple and cost-effective protocol for DNA isolation from buccal epithelial cells

Abstract: Buccal cells provide a convenient source of DNA for epidemiological studies. The goal of this study was to develop a convenient method to obtain buccal cells from mouthwash samples to be used as a source of DNA, and to evaluate the stability of the DNA in mouthwash solution over time. The procedures used in the method described in this paper avoid the use of any organic solvents. This is achieved by salting out the cellular proteins by dehydration and precipitation with a saturated ammonium acetate solution. The protocol described here is fast, simple to perform, sensitive, economical and several samples can be processed at the same time. The analyses provide consistent evidence that DNA extracted by this methodology is sufficient for several PCR amplifications. The total DNA yield ranged from 5 to 93 microg (median 15 microg, mean 20.71 microg). DNA can be extracted and PCR amplified after storage of mouthwash solution at room temperature for periods of up to 30 days.

Power system transmission network expansion planning using AC model

Abstract: An optimisation technique to solve transmission network expansion planning problem, using the AC model, is presented. This is a very complex mixed integer nonlinear programming problem. A constructive heuristic algorithm aimed at obtaining an excellent quality solution for this problem is presented. An interior point method is employed to solve nonlinear programming problems during the solution steps of the algorithm. Results of the tests, carried out with three electrical energy systems, show the capabilities of the method and also the viability of using the AC model to solve the problem.