114 resultados para Flame spread
Resumo:
Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
The present study was designed to determine the prevalence and extended-spectrum beta-lactamase (ESBL) types in clinical isolates of Klebsiella spp. at a university hospital located in the Brazilian southern region (Ribeirao Preto, Sao Paulo) as well as their antibiotic susceptibility and genetic profiles. This study included 147 non-repeat Klebsiella spp. isolates collected from January to June 2000, of which 23 K. pneumoniae and 8 K. oxytoca were selected as ESBL producers by using the Oxoid combination disk method and Etest ESBL strip. beta-lactamases were characterized by IEF, PCR and sequencing assays using primers for ESBL genes. Antibiotic susceptibility was evaluated by MicroScan system. Dissemination of two major clones of ESBL-producing Klebsiella spp. occurred in the hospital. According to the results obtained in this study there was a clonal spread of CTX-M-producing K. oxytoca in five clinics and dissemination of ESBL-producing K. pneumoniae in the nursery and pediatrics wards.
Resumo:
Enterococci have been implicated in severe human infections as a consequence of associated determinants of virulence and antimicrobial resistance. The majority of vancomycin-resistant Enterococcus faecium (VRE(fm)) connected to outbreaks worldwide pertains to the clonal complex 17 (CC17). In Brazil, the majority of VRE(fm) involved in outbreaks reported so far are not related to CC17. VRE(fm) strains responsible for an outbreak and sporadic cases in hospitals located in the city of Campinas, Brazil, were compared to other VRE(fm) strains in the country. Twenty-two out of 23 E. faecium were vancomycin-resistant and harboured the vanA gene. One vancomycin-susceptible E. faecium (VSE(fm)) strain was included in this study because it was isolated from a patient who one week later harboured a VRE(fm). All strains, except VSE, showed the same alteration in the VanA element characterised by deletion of the left extremity of the transposon and insertion of IS1251 between the vanS and vanH genes. Genes codifying virulence factors such as collageneadhesin protein, enterococcal surface protein and hyaluronidase were detected in the VRE(fm) and VSE(fm) studied. Both pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) revealed that VRE(fm) and VSE(fm) strains have a clonal relationship. New sequence types (STs) were identified by MLST as ST447, ST448, ST478 and ST412 but all belonged to the CC17. The present study revealed that VRE(fm) outbreaks in Brazil were caused by strains that did not share a common evolutionary history, and that VRE(fm) strains belonging to CC17 could be predominant in Brazil as in other countries. (C) 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Resumo:
Financial institutions are directly exposed to the credit risk, that is, the risk of the borrower not fulfill with their obligations, paying their debts in its stated periods established previously. The bank predict this type of risk, including them in their balance-sheets. In 2006/2007 there was the impact of a new financial crisis that spread around the world, known as the crisis of subprime. The objective of this study is to analyze if the provisions for credit risk or liquidation increased the sprouting of the crisis of subprime in ten major national banks, chosen accordant to their total assets. To answer this question, the balance-sheets of each one of these banks in the period of 2005 to 2007 were analyzed. This research is characterized, as for its objectives, as descriptive and as for the procedures as documentary research. It is also characterized as having a qualitative approach. The results show that the crisis of subprime has caused little impact in the credit risk provision of the analyzed institutions. It was noticed a slight increase in the provision indicators at the peak of the crisis in 2006. These percentages were reduced in, 2007, probably reflecting the economic stability of Brazil and the stagnation of the crisis Of subprime in that year, at least in relation to in our country.
Resumo:
This paper analyzes the factors that influence the issuing price of debentures in Brazil in the period from year 2000 to 2004, applying a factor model, in which exogenous variables explain return and price behavior. The variables in this study include: rating, choice of index, maturity, country risk, basic interest rate, long-term and short-term rate spread, the stock market index, and the foreign exchange rate. Results indicate that the index variable, probability of default and bond`s maturity influence pricing and points out associations of long-term bonds with better rating issues. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
This article attempts to elucidate one of the mechanisms that link trade barriers, in the form of port costs, and subsequent growth and regional inequality. Prior attention has focused on inland or link costs, but port costs can be considered as a further barrier to enhancing trade liberalization and growth. In contrast to a highway link, congestion at a port may have severe impacts that are spread over space and time whereas highway link congestion may be resolved within several hours. Since a port is part of the transportation network, any congestion/disruption is likely to ripple throughout the hinterland. In this sense, it is important to model properly the role nodal components play in the context of spatial models and international trade. In this article, a spatial computable general equilibrium (CGE) model that is integrated to a transport network system is presented to simulate the impacts of increases in port efficiency in Brazil. The role of ports of entry and ports of exit are explicitly considered to grasp the holistic picture in an integrated interregional system. Measures of efficiency for different port locations are incorporated in the calibration of the model and used as the benchmark in our simulations. Three scenarios are evaluated: (1) an overall increase in port efficiency in Brazil to achieve international standards; (2) efficiency gains associated with decentralization in port management in Brazil; and (3) regionally differentiated increases in port efficiency to reach the boundary of the national efficiency frontier.
Resumo:
We develop a forward-looking version of the recursive dynamic MIT Emissions Prediction and Policy Analysis (EPPA) model, and apply it to examine the economic implications of proposals in the US Congress to limit greenhouse gas (GHG) emissions. We find that shocks in the consumption path are smoothed out in the forward-looking model and that the lifetime welfare cost of GHG policy is lower than in the recursive model, since the forward-looking model can fully optimize over time. The forward-looking model allows us to explore issues for which it is uniquely well suited, including revenue-recycling and early action crediting. We find capital tax recycling to be more welfare-cost reducing than labor tax recycling because of its long-term effect on economic growth. Also, there are substantial incentives for early action credits; however, when spread over the full horizon of the policy they do not have a substantial effect on lifetime welfare costs.
Resumo:
We formulated a general unrestricted model of the Brazilian Emerging Markets Bond Index Plus (EMBI+) spreads, a proxy for the country`s default risk. Employing algorithms that perform automated model selection, we found that macroeconomic fundamentals, such as current account deficit ratio to gross domestic product, public deficit ratio to gross domestic product and imports over foreign exchange reserves, can explain a great part of the variation in EMBI+ spreads. There is also robust evidence of systematic contagion from Argentina and Mexico and that the variance of the spread also affects its mean.
Resumo:
Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirao Preto, University of Sao Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 mu g g(-1), 189 mu g g(-1), 20.8 mu g g(-1), and 54.0 mu g g(-1), respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
After discussing the meaning of the word politics, this paper shows that there are four possible approaches to the issue of the relationships between language, discourse and politics: a) the intrinsic political nature of language; b) the relations of power between discourses and their political dimension; c) the relations of power between languages and the political dimension of their usage and; d) linguistic policies. This paper addresses only the first two of these items. Languages have an intrinsically political nature because they subject their speakers to their order. The acts of silencing operationalized in discourse manifest a relation of power. The spread of discourses in the social space is also subject to the order of power. The use of language may be the space of pertinence, but is also that of exclusion, separation and even the elimination of the other. Therefore, language is not a neutral communication tool, but it is permeated by politics, by power. Because of the dislocations that it produces, literature is a form of swindling language, unveiling the powers that are imprinted on it.
Resumo:
A study was carried out to evaluate the feasibility of autologous adipose derived stem cells (ADSC) transplantation into female rabbits` urethra walls as an alternative to intrinsic urethral regeneration. Inguinal fat pad of 12 New Zealand adult female rabbits were harvested and processed to obtain stromal vascular fraction (SVF). The SVF were platted to isolate ADSC. Before urethral injection, cells were labeled with DiI marker. The urethra wall was injected with 1 x 10(7) autologous cells or saline (sham). The urethra was harvested at 2, 4, and 8 weeks to identify DiI-labeled cells. At 2 and 4 weeks, the ADSCs create a nodule localized in the urethral sub-mucosa. At 8 weeks, the ADSCs spread and integrated with the urethra wall from the initial injection site. This is the first study to demonstrate a successful autologous ADSCs transplantation. It confirms that ADSCs can survive and integrate within the urethral wall.
Resumo:
Background: The prognostic significance of spontaneous regression in melanoma, especially thin lesions, has been a controversial issue for the past 20 years, although recent studies suggest that extensive and late regression may be related to worse prognosis. Many data suggest that lymphangiogenesis predicts metastatic spread in melanoma. Methods: We have quantified lymphatic microvascular density (LMVD) in thin (<= 1.0 mm) superficial spreading melanomas comparing regressive and nonregressive melanomas, regressive and nonregressive areas from the same tumor, and early and late histological stages of regression in the same tumor. In addition, we tried to correlate lymphangiogenesis and tumor growth phase. We conducted histological examinations and immunohistochemical analyses using monoclonal antibody D2-40 with subsequent quantification by image analysis of 37 melanomas, 16 regressive and 21 nonregressive (controls). Results: We found higher LMVD in the late stage of regression compared with nonregressive area (internal control) of regressive melanomas. Conclusions: Our study suggest that the late stage of spontaneous regression in thin melanomas may be related to worse prognosis as it showed higher LMVD, and evidence shows that this is related with increased risk of metastatic spread. But this supposition must be confirmed by a longer follow-up for detection of lymph node metastases.
Resumo:
T-cell proliferative hypo responsiveness, a hallmark of paracoccidioidomycosis immune responses, underlies host`s failure in controlling fungus spread, being reversible with antifungal treatment. The mechanisms leading to this hypoproliferation are not well known. Since costimulatory molecules have been shown to profoundly regulate T-cell immune responses, we investigated the hypothesis that the determinants of the responder versus tolerant state may be the regulated expression of, or signaling by, costimulatory molecules. Expression of CD80, CD86, CD28, CD152, ICOS and PD-1 costimulatory molecules were examined on T-cells and monocytes harvested from stimulated and unstimulated PBMC cultures of active paracoccidioidomycosis patients and healthy individuals cured of past paracoccidioidomycosis. Stimuli were gp43, the immunodominant component of Paracoccidioides brasiliensis, and a Candida antigen. While CD28 expression, critical for optimal T-cell activation, was comparable between patients and controls, CD152, PD-1 and ICOS, which preferentially deliver negative signaling, were overexpressed on patients` stimulated and unstimutated T-cells. PBMC cultures were carried out in presence of the respective blocking antibodies which, however, failed to restore T-cell proliferation. CD80 and CD86 were equally expressed on patients` and controls` monocytes, but overexpressed on patients` T-cells. Blockade with the respective blocking antibodies on day 4 of the culture also did not restore T-cell proliferation, while, on day 0, differentially inhibited Candida and gp43 responses, suggesting that different antigens require different costimulatory pathways for antigen presentation. Our data favors the hypothesis, raised from other foreign antigen models, that prolonged in vivo antigen exposure leads to an adaptive tolerance T-cell state which is hardly reverted in vitro. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
BACKGROUND - Squamous cell carcinomas of the skin of the bead are better treated with Mobs micrographic surgery which has the lowest recurrence rates and allows spare normal tissue. There are some characteristics of squamous cell carcinoma that can be related to a higher number of surgical stages. OBJECTIVE - To study characteristic of head squamous cell carcinoma that predicts a higher number of Mohs surgical stages. METHODS - A retrospective analysis of 51 squamous cell carcinomas of the bead treated with Mobs surgery was performed to determine risk factors for a higher number of surgical stages. The characteristics analyzed were clinical limits, morphology, recurrence, histological differentiation and size and compared to the number of surgical stages. The analysis was performed by Fisher`s exact test and multivariate logistic regression. RESULTS - The recurrent squamous cell carcinomas showed a tendency for a higher number of stages (p=0,081). The Odds Ratio for a higher number of Mobs stages was three for inaccurate limits; although not statistically significant, it corroborates clinical and previous publication. CONCLUSION - Clinical characteristics of squamous cell carcinoma as recurrence and inaccurate limits would not predict, but could indicate tendency of a higher number of Mobs micrographic surgery stages.
Resumo:
Hepatitis C virus (HCV) is a frequent cause of acute and chronic hepatitis and a leading cause for cirrhosis of the liver and hepatocellular carcinoma. HCV is classified in six major genotypes and more than 70 subtypes. In Colombian blood banks, serum samples were tested for anti-HCV antibodies using a third-generation ELISA. The aim of this study was to characterize the viral sequences in plasma of 184 volunteer blood donors who attended the ""Banco Nacional de Sangre de la Cruz Roja Colombiana,`` Bogota, Colombia. Three different HCV genomic regions were amplified by nested PCR. The first of these was a segment of 180 bp of the 5`UTR region to confirm the previous diagnosis by ELISA. From those that were positive to the 5`UTR region, two further segments were amplified for genotyping and subtyping by phylogenetic analysis: a segment of 380 bp from the NS5B region; and a segment of 391 bp from the E1 region. The distribution of HCV subtypes was: 1b (82.8%), 1a (5.7%), 2a (5.7%), 2b (2.8%), and 3a (2.8%). By applying Bayesian Markov chain Monte Carlo simulation, it was estimated that HCV-1b was introduced into Bogota around 1950. Also, this subtype spread at an exponential rate between about 1970 to about 1990, after which transmission of HCV was reduced by anti-HCV testing of this population. Among Colombian blood donors, HCV genotype 1b is the most frequent genotype, especially in large urban conglomerates such as Bogota, as is the case in other South American countries. J. Med. Virol. 82: 1889-1898, 2010. (C) 2010 Wiley-Liss, Inc.