Federal University of Amazonas

Manaus, Brazil

The Federal University of Amazonas is a public university located in Manaus, state of Amazonas, Brazil. It is the largest university in the state of Amazonas and in the northern region of Brazil. It offers a wide array of degrees, with 645 research groups and 65 graduate courses. Wikipedia.

Time filter
Source Type

Francesconia F.,Federal University of Amazonas | Lupi O.,Rio de Janeiro State Federal University
Clinical Microbiology Reviews | Year: 2012

Myiasis is defined as the infestation of live vertebrates (humans and/or animals) with dipterous larvae. In mammals (including humans), dipterous larvae can feed on the host's living or dead tissue, liquid body substance, or ingested food and cause a broad range of infestations depending on the body location and the relationship of the larvae with the host. In this review, we deeply discuss myiasis as a worldwide infestation with different agents and with its broad scenario of clinical manifestations as well as diagnosis techniques and treatment. © 2012, American Society for Microbiology. All Rights Reserved.

BACKGROUND: Recent studies have shown that the inflammatory process, including the biomarker production, and the intense activation of innate immune responses are greater in the malaria caused by Plasmodium vivax than other species. Here, we examined the levels of serum biomarkers and their interaction during acute malaria.MATERIAL AND METHODS: Blood samples were collected from P. vivax-infected patients at admission and from healthy donors. Levels of serum biomarkers were measured by Cytometric Bead Assay or ELISA.RESULTS: P. vivax infection triggered the production of both inflammatory and regulatory biomarkers. Levels of IL-6, CXCL-8, IFN-γ, IL-5, and IL-10 were higher in P. vivax-infected patients than in healthy donors. On the other hand, malaria patients produced lower levels of TNF-α, IL-12p70, and IL-2 than healthy individuals. While the levels of IL-10 and IL-6 were found independent on the number of malaria episodes, higher levels of these cytokines were seen in patients with higher parasite load.CONCLUSION: A mixed pattern of proinflammatory and regulatory biomarkers is produced in P. vivax malaria. Analysis of biomarker network suggests that IL-10 and IL-6 are a robust axis in malaria patients and that this interaction seems to be associated with the parasite load.

Castro M.M.,Federal University of Amazonas
Genetics and molecular research : GMR | Year: 2011

Infection by human papillomavirus (HPV) is one of the primary causes of mortality by cancer in northern Brazil. Sexually active women from Manaus, Amazonas, without cytological alterations and women with pre-malignant and malignant cytological alterations were examined for HPV virus, identified via PCR and sequencing. The target region for this study was part of the L1 capsid gene of HPV. Twenty-three samples that were PCR-positive were sequenced. Analysis of 336 bp demonstrated a high incidence of high-risk HPV types in the population of Manaus, identified as HPVs 16, 33, 58, 66, 68. HPV type 16 was the most prevalent, presenting two variants similar to the Asian-American (AA) and East-Asian type (As) variants. A rare HPV type 13 related to "Heck's disease" was also detected. This preliminary provides important information about the HPV circulating in Amazonas State.

de Aquino P.F.,Federal University of Amazonas
Genetics and molecular research : GMR | Year: 2012

Gastric cancer is one of most frequent causes of death in Brazil. The city of Manaus has one of the highest incidences of this disease in Brazil. The Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that is classified as a group 1 carcinogen by the International Agency for Research on Cancer. We obtained biopsies from 6 control subjects and 10 patients with gastric carcinomas living in Manaus. In the patients, the samples were taken from tumors and from adjacent non-cancerous mucosa. These samples were screened for EBV DNA by PCR to amplify the 288-bp fragments from the Bam M region. The EBV DNA was detected in 8 of the 10 tumor cases and in none of the 6 control subjects. In the positively identified samples, EBV DNA was detected in five corresponding resection margins. Previous research indicated only a weak association between EBV and gastric cancer. We suggest that EBV should be considered as a risk factor for gastric adenocarcinomas in Manaus.

Silva Rd.e C.,Federal University of Amazonas | Silva Rd.e C.,University of Brasilia
Journal of proteomics | Year: 2014

UNLABELLED: In the present study we have identified and characterized the proteins expressed during different developmental stages of Elaeis guineensis calli obtained from zygotic embryos. We were interested in the possible proteomic changes that would occur during the acquisition of somatic embryogenesis and therefore samples were collected from zygotic embryos (E1), swollen explants 14days (E2) in induction medium, primary callus (E3), and pro-embryogenic callus (E4). The samples were grinded in liquid nitrogen, followed by total protein extraction using phenol and extraction buffer. Proteins were analyzed by two-dimensional electrophoresis (2-DE) and the differentially expressed protein spots were analyzed by MALDI-TOF mass spectrometry (MS and MS/MS). Interestingly, we have identified proteins, which can be used as potential candidates for future studies aiming at the development of biomarkers for embryogenesis acquisition and for the different stages leading to pro-embryogenic callus formation such as type IIIa membrane protein cp-wap13, fructokinase and PR proteins. The results obtained shed some light on the biochemical events involved in the process of somatic embryogenesis of E. guineensis obtained from zygotic embryos. The use of stage-specific protein markers can help monitor cell differentiation and contribute to improve the protocols for successfully cloning the species.BIOLOGICAL SIGNIFICANCE: Understanding the fate and dynamics of cells and tissues during callus formation is essential to understand totipotency and the mechanisms involved during acquisition of somatic embryogenesis (SE). In this study we have investigated the early stages of somatic embryogenesis induction in oil palm and have identified potential markers as well as proteins potentially involved in embryogenic competence acquisition. The use of these proteins can help improve tissue culture protocols in order to increase regeneration rates. This article is part of a Special Issue entitled: Environmental and structural proteomics. Copyright © 2014 Elsevier B.V. All rights reserved.

Figueiredo Neto E.M.,Federal University of Amazonas
Revista brasileira de reumatologia | Year: 2011

To evaluate the quality of life and its association with daily physical activity in different contexts of life in osteoarthritis patients referred from Basic Health Care Units to a university-affiliated service. This is a crosssectional, case series study in which physical activity was evaluated by the International Physical Activity Questionnaire (IPAQ), and quality of life was assessed by the Medical Outcomes Study 36 Short-Form Health Survey (SF-36), Western Ontario and McMaster Universities Index (WOMAC), and Australian/Canadian Osteoarthritis Hand Index (AUSCAN). To evaluate pain intensity, a Visual Analogue Scale (VAS) was also used. One hundred patients (92 women and eight men; mean age 59.9 ± 9.4 years) were included. The most affected joints were the knees and hands. Ten patients had only a single joint affected, 69 patients had two, eight patients had three, and 13 patients had four joints affected. The IPAQ showed that 70 patients were active or very active, while 30 were insufficiently active or sedentary. Physical activity was positively associated with the SF-36 domains that assess physical health (physical functioning, physical role, pain, general health perceptions). There was an association between physical activity and quality of life assessed by WOMAC, and the more severe the pain, the worse the quality of life. In most patients in this population, the physical aspects of the quality of life are worse, but they maintain their daily physical activities.

Filho J.D.A.M.,Federal University of Amazonas | Silva F.D.A.,Federal University of Rio de Janeiro | Toledo Filho R.D.,Federal University of Rio de Janeiro
Cement and Concrete Composites | Year: 2013

The kinetics of vegetable (sisal) fiber degradation and the mechanisms responsible for deterioration of continuous sisal fiber cement composites are presented in this paper. Two matrices were used: one with 50% partial cement replacement by metakaolin (PC-MK) and a reference matrix having as binder only Portland cement (PC). The durability performance of the composite systems is examined and the mechanisms for the significant delay in the fiber degradation when the total amount of calcium hydroxide is reduced from the matrix discussed. The composites were subjected to 5, 10, 15, 20 and 25 cycles of wetting and drying and then tested under a four point bending load configuration in order to determine the flexural behavior and cracking mechanisms with progressive aging. Furthermore, composites stored under controlled lab conditions were tested under bending load at ages ranging from 28 days to 5 years. Fibers extracted from the aged composites were subjected to thermal analysis, Fourier transform infrared spectroscopy and microscopical observations in order to evaluate the changes in chemical composition and microstructure. Two fiber degradation mechanisms were observed in the PC composites: fiber mineralization due to the precipitation of calcium hydroxide in the fiber cell and surface and degradation of cellulose, hemicellulose and lignin due to the adsorption of calcium and hydroxyl ions. The degradation process occurs rapidly and after 10 cycles of wetting/drying a quite expressive modification in the flexural behavior is observed. The residual mechanical parameters after 25 cycles were the same as those observed in the unreinforced matrix. For the PC-MK composite fiber mineralization was not observed due to the low content of CH in the matrix. © 2013 Elsevier Ltd. All rights reserved.

Galiceanu M.,Federal University of Amazonas
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

We focus on polymer networks with a scale-free topology. In the framework of generalized Gaussian structures, by making use of the eigenvalue spectrum of the connectivity matrix, we determined numerically the averaged monomer displacement under external forces and the mechanical relaxation moduli (storage and loss modulus). First, we monitor these physical quantities and additionally the eigenvalue spectrum for structures of different sizes, but with the same γ, which is a parameter that measures the connectivity of the structure. Second, we vary the parameter γ, and we keep constant the size of the structures. This allows us to study in detail the crossover behavior from a simple linear chain to a starlike structure. As expected we encounter a more chainlike behavior for high values of γ, while for small values of γ a more starlike behavior is observed. In the intermediate time (frequency) domain, we encounter regions of constant slope for some intermediate values of γ. © 2012 American Physical Society.

Figueiredo L.C.,Federal University of Amazonas
Genetics and molecular research : GMR | Year: 2011

The current intense production of biological data, generated by sequencing techniques, has created an ever-growing volume of unanalyzed data. We reevaluated data produced by the guarana (Paullinia cupana) transcriptome sequencing project to identify cDNA clones with complete coding sequences (full-length clones) and complete sequences of genes of biotechnological interest, contributing to the knowledge of biological characteristics of this organism. We analyzed 15,490 ESTs of guarana in search of clones with complete coding regions. A total of 12,402 sequences were analyzed using BLAST, and 4697 full-length clones were identified, responsible for the production of 2297 different proteins. Eighty-four clones were identified as full-length for N-methyltransferase and 18 were sequenced in both directions to obtain the complete genome sequence, and confirm the search made in silico for full-length clones. Phylogenetic analyses were made with the complete genome sequences of three clones, which showed only 0.017% dissimilarity; these are phylogenetically close to the caffeine synthase of Theobroma cacao. The search for full-length clones allowed the identification of numerous clones that had the complete coding region, demonstrating this to be an efficient and useful tool in the process of biological data mining. The sequencing of the complete coding region of identified full-length clones corroborated the data from the in silico search, strengthening its efficiency and utility.

Cordeiro L.,Federal University of Amazonas | Fischer B.,University of Southampton | Marques-Silva J.,University College Dublin
IEEE Transactions on Software Engineering | Year: 2012

Propositional bounded model checking has been applied successfully to verify embedded software, but remains limited by increasing propositional formula sizes and the loss of high-level information during the translation preventing potential optimizations to reduce the state space to be explored. These limitations can be overcome by encoding high-level information in theories richer than propositional logic and using SMT solvers for the generated verification conditions. Here, we propose the application of different background theories and SMT solvers to the verification of embedded software written in ANSI-C in order to improve scalability and precision in a completely automatic way. We have modified and extended the encodings from previous SMT-based bounded model checkers to provide more accurate support for variables of finite bit width, bit-vector operations, arrays, structures, unions, and pointers. We have integrated the CVC3, Boolector, and Z3 solvers with the CBMC front-end and evaluated them using both standard software model checking benchmarks and typical embedded software applications from telecommunications, control systems, and medical devices. The experiments show that our ESBMC model checker can analyze larger problems than existing tools and substantially reduce the verification time. © 2012 IEEE.

Loading Federal University of Amazonas collaborators
Loading Federal University of Amazonas collaborators