263 resultados para caveat against dealings


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim. The study aimed at describing the evolution over a 6-year period of patients leaving the emergency department (ED) before being seen ("left without being seen" or LWBS) or against medical advice ("left against medical advice" or LAMA) and at describing their characteristics. Methods. A retrospective database analysis of all adult patients who are admitted to the ED, between 2005 and 2010, and who left before being evaluated or against medical advice, in a tertiary university hospital. Results. During the study period, among the 307,716 patients who were registered in the ED, 1,157 LWBS (0.4%) and 1,853 LAMA (0.9%) patients were identified. These proportions remained stable over the period. The patients had an average age of 38.5 ± 15.9 years for LWBS and 41.9 ± 17.4 years for LAMA. The median time spent in the ED before leaving was 102.4 minutes for the LWBS patients and 226 minutes for LAMA patients. The most frequent reason for LAMA was related to the excessive length of stay. Conclusion. The rates of LWBS and LAMA patients were low and remained stable. The patients shared similar characteristics and reasons for leaving were largely related to the length of stay or waiting time.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bacteria can survive on hospital textiles and surfaces, from which they can be disseminated, representing a source of health care-associated infections (HCAIs). Surfaces containing copper (Cu), which is known for its bactericidal properties, could be an efficient way to lower the burden of potential pathogens. The antimicrobial activity of Cu-sputtered polyester surfaces, obtained by direct-current magnetron sputtering (DCMS), against methicillin-resistant Staphylococcus aureus (MRSA) was tested. The Cu-polyester microstructure was characterized by high-resolution transmission electron microscopy to determine the microstructure of the Cu nanoparticles and by profilometry to assess the thickness of the layers. Sputtering at 300 mA for 160 s led to a Cu film thickness of 20 nm (100 Cu layers) containing 0.209% (wt/wt) polyester. The viability of MRSA strain ATCC 43300 on Cu-sputtered polyester was evaluated by four methods: (i) mechanical detachment, (ii) microcalorimetry, (iii) direct transfer onto plates, and (iv) stereomicroscopy. The low efficacy of mechanical detachment impeded bacterial viability estimations. Microcalorimetry provided only semiquantitative results. Direct transfer onto plates and stereomicroscopy seemed to be the most suitable methods to evaluate the bacterial inactivation potential of Cu-sputtered polyester surfaces, since they presented the least experimental bias. Cu-polyester samples sputtered for 160 s by DCMS were further tested against 10 clinical MRSA isolates and showed a high level of bactericidal activity, with a 4-log(10) reduction in the initial MRSA load (10(6) CFU) within 1 h. Cu-sputtered polyester surfaces might be of use to prevent the transmission of HCAI pathogens.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Two long synthetic peptides representing the dimorphic and constant C-terminal domains of the two allelic families of Plasmodium falciparum merozoite surface proteins 2 are considered promising malaria vaccine candidates. The aim of the current study is to characterize the immune response (epitope mapping) in naturally exposed individuals and relate immune responses to the risk of clinical malaria. METHODS: To optimize their construction, the fine specificity of human serum antibodies from donors of different age, sex and living in four distinct endemic regions was determined in ELISA by using overlapping 20 mer peptides covering the two domains. Immune purified antibodies were used in Western blot and immunofluorescence assay to recognize native parasite derivate proteins. RESULTS: Immunodominant epitopes were characterized, and their distribution was similar irrespective of geographic origin, age group and gender. Acquisition of a 3D7 family and constant region-specific immune response and antibody avidity maturation occur early in life while a longer period is needed for the corresponding FC27 family response. In addition, the antibody response to individual epitopes within the 3D7 family-specific region contributes to protection from malaria infection with different statistical weight. It is also illustrated that affinity-purified antibodies against the dimorphic or constant regions recognized homologous and heterologous parasites in immunofluorescence and homologous and heterologous MSP2 and other polypeptides in Western blot. CONCLUSION: Data from this current study may contribute to a development of MSP2 vaccine candidates based on conserved and dimorphic regions thus bypassing the complexity of vaccine development related to the polymorphism of full-length MSP2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In recent years, the fight against money laundering has emerged as a key issue of financial regulation. The Wolfsberg Group is an important multistakeholder agreement establishing corporate responsibility (CR) principles against money laundering in a domain where international coordination remains otherwise difficult. The fact that 10 out of the 25 top private banking institutions joined this initiative opens up an interesting puzzle concerning the conditions for the participation of key industry players in the Wolfsberg Group. The article presents a fuzzy-set analysis of seven hypotheses based on firm-level organizational factors, the macro-institutional context, and the regulatory framework. Results from the analysis of these 25 financial institutions show that public ownership of the bank and the existence of a code of conduct are necessary conditions for participation in the Wolfsberg Group, whereas factors related to the type of financial institution, combined with the existence of a black list, are sufficient for explaining participation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Malaria is one of the most important tropical and infectious diseases causing many deaths and enormous social and economic consequences, particularly in the developing countries. Despite of widely use of anti-malaria drugs and insecticide, the development of successful vaccines constitutes one of the main strategies to control malaria transmission. Several proteins expressed from blood stage such as merozoite surface proteins (MSP] or liver stage as circumsporozoite protein (CSP) are shown to be the targets of immune responses in humans and in animals. Thus, several studies have illustrated that natural infection and laboratory immunizations of humans and animals with Plasmodium sporozoite (SPZ) and its derivate-proteins (peptides) can elicit protection and control of parasite infection. However, a clear understanding of immune response against defined Plasmodium proteins should be the prerequisite conditions before any development of appropriate vaccines. In this order, our study focused on the immune responses to MSP2 (dimorphic and C-terminal fragments) in human and mice; and the mechanisms by which mouse infected hepatocytes present Plasmodium antigens to CD8+ T-cells to induce protective immunity in mice.¦The first part of this work shows that infected hepatocytes can present Plasmodium antigens to PbCSP-specific CD8+ T-cells and induce a protective immunity in mice. Here, this was addressed in vivo and showed that the infected hepatocytes were able of stimulating of primed-and naive-CD8+ T-cell clones and induced fully protective immunity against SPZ challenge. The role of infected hepatocytes in antigen presentation was illustrated here by their graft into immuno-deficient mice and depletion of cosspresenting dentritic cells (DCs) that are known to have key role in the activation of CD8+ T-cells during the liver cycle stage of Plasmodium.¦The second part of this project concerned the fine specificity of Ab responses regarding D and C regions of the two allelic families of MSP2 (3D7 and FC27). Covering of the two regions by overlapping-20 mers led to delineate the epitopes in the different endemic areas and different age groups of donors. The major epitopes characterizing D or C regions were conserved in different endemic areas (P12/P13 and P15/P16 for the 3D7-D, P23/24 and P25/26 for the FC27-D; P29/P30 for the C region). This offers thus, the possibility of a multi-epitope vaccine design including the major epitopes from the two domains of the two allelic MSP2 families. On the other, the 20 mers, particularly some major epitopes of the 3D7-Dregion (P12, P13 and P16) belonged to the epitopes that presented a high probability to be associated with protection in the children group [1 to 5 year-old). In addition, D and C LSP purified Abs (pAbs) recognized merozoite derived polypeptides and native proteins. A crossreactivity activity of homologous pAbs against the heterologous was also illustrated between the two allelic MSP2 parasites. Finally, the functional analysis of D regions pAbs showed an inhibition of Plasmodium falciparum growth suggesting the functional biological activity of the D region pAbs in the control of malaria.¦The last part of this project aimed the evaluation of the immunogenicity of the D and C region LSPs of the two allelic MSP2 families in the presence of adjuvants for the possible use in clinical trial study in humans. The MSP2 LSP mixture showed that D and C were immunogenic and defined limited epitopes (whose intensity of immune responses) depending on the adjuvants and mouse strain for the D regions. The major epitopes characterizing the C region were usually conserved in different strains of mouse and adjuvants used. Furthermore, the single region (either with D or C) immunization of mice confirmed the immunogenicity and the presence of their limited epitopes. We concluded that the possibility to finely delineate in animals the immune responses to antigens might help to select optimal antigen/adjuvant combinations to be tested later in clinical trials. Thus, formulation of glucopyranosyl-lipid A stable emulsion, GLA-SE (toll like receptor (TLR) 4 agonist) and its different combination (CpG: TLR9 agonist and GDQ: LR7 agonist) with MSP2 LSP was better than with alum, montanide ISA 720 (Mt) and virosome. Immunization of mice with allelic LSP did not show a crossreactivity between the two allelic MSP2 parasites unlike as humans, suggesting that the crossreactivity could be acquired during natural infection of the population who are usually exposed to both allelic parasite forms (3D7 and FC27).¦Nevertheless, similar epitope of D (P12, P13 and P25) and C (P29) regions have been found both in mice and human. This offers an opportunity to compare their epitopes in naïve immunized donors with LSPs and naturally infected populations in the endemic areas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Analysis of TRIM5α and APOBEC3G genes suggests that these two restriction factors underwent strong positive selection throughout primate evolution. This pressure was possibly imposed by ancient exogenous retroviruses, of which endogenous retroviruses are remnants. Our study aims to assess in vitro the activity of these factors against ancient retroviruses by reconstructing their ancestral gag sequences, as well as the ancestral TRIM5α and APOBEC3G for primates. Based on evolutionary genomics approach, we reconstructed ancestors of the two largest families of human endogenous retroviruses (HERV), namely HERV-K and HERV-H, as well as primate ancestral TRIM5α and APOBEC3G variants. The oldest TRIM5α sequence was the catarhinne TRIM5α, common ancestor of Old World monkeys and hominoids, dated from 25 million years ago (mya). From the oldest, to the youngest, ancestral TRIM5α variants showed less restriction of HIV-1 in vitro [1]. Likewise three ancestral APOBEC3Gs sequences common to hominoids (18 mya), Old World monkeys, and catarhinnes (25 mya) were reconstructed. All ancestral APOBEC3G variants inhibited efficiently HIV-1Δvif in vitro, compared to modern APOBEC3Gs. The ability of Vif proteins (HIV-1, HIV-2, SIVmac and SIVagm) to counteract their activity tallied with the residue 128 on ancestral APOBEC3Gs. Moreover we are attempting to reconstruct older ancestral sequences of both restriction factors by using prosimian orthologue sequences. An infectious onemillion- years-old HERV-KCON previously reconstituted was shown to be resistant to modern TRIM5α and APOBEC3G [2]. Our ancestral TRIM5α and APOBEC3G variants were inactive against HERV-KCON. Besides we reconstructed chimeric HERV-K bearing ancestral capsids (up to 7 mya) that resulted in infectious viruses resistant to modern and ancestral TRIM5α. Likewise HERV-K viruses bearing ancestral nucleocapsids will be tested for ancestral and modern APOBEC3G restriction. In silico reconstruction and structural modeling of ancestral HERV-H capsids resulted in structures homologous to that of the gammaretrovirus MLV. Thus we are attempting to construct chimeric MLV virus bearing HERV-H ancestral capsids. These chimeric ancestral HERVs will be tested for infectivity and restriction by ancestral TRIM5α. Similarly chimeric MLV viruses bearing ancestral HERV-H nucleocapsids will be reconstructed and tested for APOBEC3G restriction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In a murine model of experimental cutaneous leishmaniasis, we investigated the protection elicited by injection of histone H1 isolated from parasites by perchloric extraction, of a H1 recombinant protein produced in E. coli, and of H1 long and short synthetic peptides, against infection by L. major. Partial protection was achieved in most of the animals as shown by reduction in lesion size, upon immunization with histone H1 or its peptides, provided that the region 1-60 was present in the molecule. These observations argue in favor of a thorough examination of the possibility of including histone H1 described here in a cocktail vaccine against human leishmaniasis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The infection mechanism of vaccinia virus is largely unknown. Neither the attachment protein of extracellular enveloped virus (EEV), the biologically relevant infectious form of the virus, nor its cellular receptor has been identified. Surprisingly, all former attempts using antibodies to block EEV infection of cells in vitro had failed. Here, we report the production of an anti-envelope hyperimmune serum with EEV neutralizing activity and show that a polyclonal antiserum against the extraviral domain of protein B5R also inhibited EEV infection. In vivo, mice vaccinated with B5R protein were protected against a lethal vaccinia virus challenge. This protectivity is likely to be mediated by neutralizing antibodies. Protein A33R, but not A34R and A36R, also proved to be protective in active and passive vaccination experiments. However, in contrast to B5R, A33R protectivity did not correlate with antibody titers. Because anti-A33R antibodies did not neutralize EEV in vitro, the protectivity mediated by A33R protein probably involves a mechanism different from simple antibody binding. Taken together, our results suggest that antibodies to a specific protective epitope or epitopes on protein B5R are able to prevent EEV infection. The protein encoded by the B5R gene is therefore likely to play a crucial role in the initial steps of vaccinia virus infection-binding to a host cell and entry into its cytoplasm.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: carbon nanotubes (CNT) can have adverse effects on health. Therefore, minimizing the risk associated with CNT exposure is of crucial importance. The aim of this work was to evaluate if coating multi-walled CNT (MWCNT) with polymers could modify their toxicity, thus representing a useful strategy to decrease adverse health effects of CNT. We used industrially-produced MWCNT uncoated (NT1) or coated (50/50 wt%) with acid-based (NT2) or polystyrene-based (NT3) polymer, and exposed murine macrophages (RAW 264.7 cell line) or Balb/c mice by intratracheal administration. Biological experiments were performed both in vitro and in vivo, examining time- and dose-dependent effects of CNT, in terms of cytotoxicity, expression of genes and proteins related to oxidative stress, inflammation and tissue remodeling, cell and lung tissue morphology (optical and transmission electron microscopy), and bronchoalveolar lavage fluid content analysis.RESULTS: extensive physico-chemical characterization of MWCNT was performed, and showed, although similar dimensions for the 3 MWCNT, a much smaller specific surface area for NT2 and NT3 as compared to NT1 (54.1, 34 and 227.54 m(2)/g respectively), along with different surface characteristics. MWCNT-induced cytotoxicity, oxidative stress, and inflammation were increased by acid-based and decreased by polystyrene-based polymer coating both in vitro in murine macrophages and in vivo in lung of mice monitored for 6 months.CONCLUSIONS: these results demonstrate that coating CNT with polymers, without affecting their intrinsic structure, may constitute a useful strategy for decreasing CNT toxicity, and may hold promise for improving occupational safety and that of general the user.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocontrol.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The weak selection approximation of population genetics has made possible the analysis of social evolution under a considerable variety of biological scenarios. Despite its extensive usage, the accuracy of weak selection in predicting the emergence of altruism under limited dispersal when selection intensity increases remains unclear. Here, we derive the condition for the spread of an altruistic mutant in the infinite island model of dispersal under a Moran reproductive process and arbitrary strength of selection. The simplicity of the model allows us to compare weak and strong selection regimes analytically. Our results demonstrate that the weak selection approximation is robust to moderate increases in selection intensity and therefore provides a good approximation to understand the invasion of altruism in spatially structured population. In particular, we find that the weak selection approximation is excellent even if selection is very strong, when either migration is much stronger than selection or when patches are large. Importantly, we emphasize that the weak selection approximation provides the ideal condition for the invasion of altruism, and increasing selection intensity will impede the emergence of altruism. We discuss that this should also hold for more complicated life cycles and for culturally transmitted altruism. Using the weak selection approximation is therefore unlikely to miss out on any demographic scenario that lead to the evolution of altruism under limited dispersal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To link the presence of intrathecal virus-specific oligoclonal immunoglobulin G (IgG) in multiple sclerosis patients to a demyelinating activity, aggregating rat brain cell cultures were treated with antibodies directed against two viruses, namely, rubella (RV) and hepatitis B (HB). Anti-RV antibodies in the presence of complement decreased myelin basic protein concentrations in a dose-dependent manner, whereas anti-HB antibodies had no effect. A similar but less pronounced effect was observed on the enzymatic activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase, which is enriched in noncompact membranes of oligodendrocytes. These effects were comparable to those in cultures treated with antibodies directed against myelin oligodendrocyte glycoprotein (MOG), previously found to be myelinotoxic both in vitro and in vivo. Sequence homologies were found between structural glycoprotein E(2) of RV and MOG, suggesting that demyelination was due to molecular mimicry. To support the hypothesis that demyelination was caused by anti-RV IgG that recognized an MOG epitope, we found that anti-RV antibodies depleted MOG in a dose-dependent manner. Further evidence came from the demonstration that anti-RV and anti-MOG IgG colocalized on oligodendrocyte processes and that both revealed by Western blot a 28 kDa protein in CNS myelin, a molecular weight corresponding to MOG. These findings suggest that a virus such as RV exhibiting molecular mimicry with MOG can trigger an autoimmune demyelination.