414 research outputs found

    Willingness to pay for human papillomavirus vaccine in Metropolitan Santiago, Chile

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    Cerda, AA (Cerda, Arcadio A ; Gaete, FI (Gaete, Fabian I.) ; Pizarro, TH (Pizarro, Tomas H.). Univ Talca, Fac Ciencias Empresariales, Talca, ChileWillingness to pay for human papillomavirus vaccine in Metropolitan Santiago, Chile Background: Human papillomavirus (HPV) infection is a risk factor for cervical cancer and can be prevented with the HPV vaccine. Aim: To explore the willingness of parents to pay for HPV vaccine for their offspring. Material and Methods: A survey about the willingness to pay for HPV vaccine was answered by 386 individuals of the highest socioeconomic level who had a daughter aged between 12 and 18 years. The survey included information about the risks of HPV infection. Results: Parents would pay a mean of US$ 758 for the vaccine. Twenty five percent of parents were not willing to pay for it. If the cost of the vaccine would be reduced by 50%, only 4% of parents would not pay for it. The willingness to pay is associated with the price of the vaccine, the income level of respondents and the size of the family. Conclusions: Most respondents would pay for HPV vaccine for their daughters, despite the relatively high cost. (Rev Med Chile 2013; 141: 167-172)

    Relación entre el amor concreto y la violencia percibida y practicada en la pareja en jóvenes de San Juan de Lurigancho, Lima, 2019

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    La presente investigación titulada: Relación entre el amor concreto y la violencia percibida y practicada en la pareja en jóvenes de San Juan de Lurigancho, Lima. La metodología es de tipo descriptiva – correlacional simple. La muestra es probabilístico intencional fue de 418 personas de ambos sexos que oscilan entre los 20 a 40 años de edad. En esta investigación se estudia la variable amor concreto y para ello se utilizó el cuestionario de actividades del amor concreto, con la finalidad de medir el nivel del amor. Así mismo para la variable violencia se utilizó el “EVP percibida en jóvenes y adultos” tanto percibida como practicada, con la finalidad de medir el nivel de violencia en la pareja. Los resultados muestran una correlación significativa e inversa entre el amor y la violencia de pareja, (p: 0.000; r< -0,27)

    Aptitud química y toxicológica del agua para consumo animal en el sudoeste bonaerense semiárido

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    Se presenta una actualización de la base de datos georreferenciada, con la generación de mapas que permiten conocer la distribución geográfica y caracterizar un importante número de fuentes de agua para consumo animal en el Sudoeste Bonaerense Semiárido.EEA BordenaveFil: Cerdá, Carmen Corina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Pizarro, María José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Tornquist; ArgentinaFernández, Eduardo Luján. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin

    Brucella Evades Macrophage Killing via VirB-dependent Sustained Interactions with the Endoplasmic Reticulum

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    The intracellular pathogen Brucella is the causative agent of brucellosis, a worldwide zoonosis that affects mammals, including humans. Essential to Brucella virulence is its ability to survive and replicate inside host macrophages, yet the underlying mechanisms and the nature of the replicative compartment remain unclear. Here we show in a model of Brucella abortus infection of murine bone marrow–derived macrophages that a fraction of the bacteria that survive an initial macrophage killing proceed to replicate in a compartment segregated from the endocytic pathway. The maturation of the Brucella-containing vacuole involves sustained interactions and fusion with the endoplasmic reticulum (ER), which creates a replicative compartment with ER-like properties. The acquisition of ER membranes by replicating Brucella is independent of ER-Golgi COPI-dependent vesicular transport. A mutant of the VirB type IV secretion system, which is necessary for intracellular survival, was unable to sustain interactions and fuse with the ER, and was killed via eventual fusion with lysosomes. Thus, we demonstrate that live intracellular Brucella evade macrophage killing through VirB-dependent sustained interactions with the ER. Moreover, we assign an intracellular function to the VirB system, as being required for late maturation events necessary for the biogenesis of an ER-derived replicative organelle

    Regulation of surface architecture by symbiotic bacteria mediates host colonization

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    Microbes occupy countless ecological niches in nature. Sometimes these environments may be on or within another organism, as is the case in both microbial infections and symbiosis of mammals. Unlike pathogens that establish opportunistic infections, hundreds of human commensal bacterial species establish a lifelong cohabitation with their hosts. Although many virulence factors of infectious bacteria have been described, the molecular mechanisms used during beneficial host–symbiont colonization remain almost entirely unknown. The novel identification of multiple surface polysaccharides in the important human symbiont Bacteroides fragilis raised the critical question of how these molecules contribute to commensalism. To understand the function of the bacterial capsule during symbiotic colonization of mammals, we generated B. fragilis strains deleted in the global regulator of polysaccharide expression and isolated mutants with defects in capsule expression. Surprisingly, attempts to completely eliminate capsule production are not tolerated by the microorganism, which displays growth deficits and subsequent reversion to express capsular polysaccharides. We identify an alternative pathway by which B. fragilis is able to reestablish capsule production and modulate expression of surface structures. Most importantly, mutants expressing single, defined surface polysaccharides are defective for intestinal colonization compared with bacteria expressing a complete polysaccharide repertoire. Restoring the expression of multiple capsular polysaccharides rescues the inability of mutants to compete for commensalism. These findings suggest a model whereby display of multiple capsular polysaccharides provides essential functions for bacterial colonization during host–symbiont mutualism

    The outer membranes of Brucella spp. are resistant to bactericidal cationic peptides

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    The actions of polymyxin B, rabbit polymorphonuclear lysosome extracts, 14 polycationic peptides (including defensin NP-2, cecropin P1, lactoferricin B, and active peptides from cationic protein 18 and bactenecin), EDTA, and Tris on Brucella spp. were studied, with other gram-negative bacteria as controls. Brucella spp. were comparatively resistant to all of the agents listed above and bound less polymyxin B, and their outer membranes (OMs) were neither morphologically altered nor permeabilized to lysozyme by polymyxin B concentrations, although both effects were observed for controls. EDTA and peptides increased or accelerated the partition of the hydrophobic probe N-phenyl-naphthylamine into Escherichia coli and Haemophilus influenzae OMs but had no effect on Brucella OMs. Since Brucella and H. influenzae OMs are permeable to hydrophobic compounds (G. Martínez de Tejada and I. Moriyón, J. Bacteriol. 175:5273-5275, 1993), the results show that such unusual permeability is not necessarily related to resistance to polycations. Although rough (R) B. abortus and B. ovis were more resistant than the controls were, there were qualitative and quantitative differences with smooth (S) brucellae; this may explain known host range and virulence differences. Brucella S-lipopolysaccharides (LPSs) had reduced affinities for polycations, and insertion of Brucella and Salmonella montevideo S-LPSs into the OM of a Brucella R-LPS mutant increased and decreased, respectively, its resistance to cationic peptides. The results show that the core lipid A of Brucella LPS plays a major role in polycation resistance and that O-chain density also contributes significantly. It is proposed that the features described above contribute to Brucella resistance to the oxygen-independent systems of phagocytes

    Septins Regulate Bacterial Entry into Host Cells

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    Background: Septins are conserved GTPases that form filaments and are required in many organisms for several processes including cytokinesis. We previously identified SEPT9 associated with phagosomes containing latex beads coated with the Listeria surface protein InlB. Methodology/Principal Findings: Here, we investigated septin function during entry of invasive bacteria in non-phagocytic mammalian cells. We found that SEPT9, and its interacting partners SEPT2 and SEPT11, are recruited as collars next to actin at the site of entry of Listeria and Shigella. SEPT2-depletion by siRNA decreased bacterial invasion, suggesting that septins have roles during particle entry. Incubating cells with InlB-coated beads confirmed an essential role for SEPT2. Moreover, SEPT2-depletion impaired InlB-mediated stimulation of Met-dependent signaling as shown by FRET. Conclusions/Significance: Together these findings highlight novel roles for SEPT2, and distinguish the roles of septin an

    Mechanistic insights into simultaneous removal of copper, cadmium and arsenic from water by iron oxide-functionalized magnetic imogolite nanocomposites

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    Imogolite and magnetic imogolite-Fe oxide nanocomposites (Imo-Fe50 and Imo-Fe25, at 50 and 25 % Fe loading (w/w), respectively) were synthesized and tested for the removal of aqueous copper (Cu), cadmium (Cd), and arsenic (As) pollutants. The materials were characterized by transmission electron microscopy, and specific surface area and isoelectric point measurements. The Fe-containing samples were additionally characterized by Mössbauer spectroscopy and vibrating-sample magnetometry. Significant differences were found in the morphological, electrophoretic, and magnetic characteristics between imogolite and the nanocomposites. The in-situ Fe-oxide precipitation process modified the active surface sites of the imogolite. The Fe–oxide, mainly magnetite, favored the contaminants’ adsorption over the pristine imogolite. The adsorption kinetics of these pollutants were adequately described by the pseudo-second order and intraparticle diffusion models. The kinetic models showed that surface adsorption was more important than intraparticle diffusion in the removal of the pollutants by all the adsorbents. The Langmuir-Freundlich model described the experimental adsorption data, and both nanocomposites showed greater adsorption capacity than the imogolite. The adsorption of Cu and Cd was sensitive to cationic competition, showing a decrease of the adsorption capacity when the two cations coexisted, while their adsorption increased in the presence of arsenate

    Brucella-Salmonella lipopolysaccharide chimeras are less permeable to hydrophobic probes and more sensitive to cationic peptides and EDTA than are their native Brucella sp. counterparts

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    A rough (R) Brucella abortus 45/20 mutant was more sensitive to the bactericidal activity of polymyxin B and lactoferricin B than was its smooth (S) counterpart but considerably more resistant than Salmonella montevideo. The outer membrane (OM) and isolated lipopolysaccharide (LPS) of S. montevideo showed a higher affinity for these cationic peptides than did the corresponding B. abortus OM and LPS. We took advantage of the moderate sensitivity of R B. abortus to cationic peptides to construct live R B. abortus-S-LPS chimeras to test the activities of polymyxin B, lactoferricin B, and EDTA. Homogeneous and abundant peripheral distribution of the heterologous S-LPS was observed on the surface of the chimeras, and this coating had no effect on the viability or morphology of the cells. When the heterologous LPS corresponded to the less sensitive bacterium S B. abortus S19, the chimeras were more resistant to cationic peptides; in contrast, when the S-LPS was from the more sensitive bacterium S. montevideo, the chimeras were more susceptible to the action of peptides and EDTA. A direct correlation between the amount of heterologous S-LPS on the surface of chimeric Brucella cells and peptide sensitivity was observed. Whereas the damage produced by polymyxin B in S. montevideo and B. abortus-S. montevideo S-LPS chimeras was manifested mainly as OM blebbing and inner membrane rolling, lactoferricin B caused inner membrane detachment, vacuolization, and the formation of internal electron-dense granules in these cells. Native S and R B. abortus strains were permeable to the hydrophobic probe N-phenyl-1-naphthylamine (NPN). In contrast, only reduced amounts of NPN partitioned into the OMs of the S. montevideo and B. abortus-S. montevideo S-LPS chimeras. Following peptide exposure, accelerated NPN uptake similar to that observed for S. montevideo was detected for the B. abortus-S. montevideo LPS chimeras. The partition of NPN into native or EDTA-, polymyxin B-, or lactoferricin B-treated LPS micelles of S. montevideo or B. abortus mimicked the effects observed with intact cells, and this was confirmed by using micelle hybrids of B. abortus and S. montevideo LPSs. The results showed that LPS is the main cause of B. abortus' resistance to bactericidal cationic peptides, the OM-disturbing action of divalent cationic chelants, and OM permeability to hydrophobic substances. It is proposed that these three features are related to the ability of Brucella bacteria to multiply within phagocytes

    The Human Fungal Pathogen Cryptococcus neoformans Escapes Macrophages by a Phagosome Emptying Mechanism That Is Inhibited by Arp2/3 Complex-Mediated Actin Polymerisation

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    The lysis of infected cells by disease-causing microorganisms is an efficient but risky strategy for disseminated infection, as it exposes the pathogen to the full repertoire of the host's immune system. Cryptococcus neoformans is a widespread fungal pathogen that causes a fatal meningitis in HIV and other immunocompromised patients. Following intracellular growth, cryptococci are able to escape their host cells by a non-lytic expulsive mechanism that may contribute to the invasion of the central nervous system. Non-lytic escape is also exhibited by some bacterial pathogens and is likely to facilitate long-term avoidance of the host immune system during latency. Here we show that phagosomes containing intracellular cryptococci undergo repeated cycles of actin polymerisation. These actin ‘flashes’ occur in both murine and human macrophages and are dependent on classical WASP-Arp2/3 complex mediated actin filament nucleation. Three dimensional confocal imaging time lapse revealed that such flashes are highly dynamic actin cages that form around the phagosome. Using fluorescent dextran as a phagosome membrane integrity probe, we find that the non-lytic expulsion of Cryptococcus occurs through fusion of the phagosome and plasma membranes and that, prior to expulsion, 95% of phagosomes become permeabilised, an event that is immediately followed by an actin flash. By using pharmacological agents to modulate both actin dynamics and upstream signalling events, we show that flash occurrence is inversely related to cryptococcal expulsion, suggesting that flashes may act to temporarily inhibit expulsion from infected phagocytes. In conclusion, our data reveal the existence of a novel actin-dependent process on phagosomes containing cryptococci that acts as a potential block to expulsion of Cryptococcus and may have significant implications for the dissemination of, and CNS invasion by, this organism.\ud \u
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