2,248 research outputs found

    Supramolecular structure in the membrane of Staphylococcus aureus

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    The fundamental processes of life are organized and based on common basic principles. Molecular organizers, often interacting with the membrane, capitalize on cellular polarity to precisely orientate essential processes. The study of organisms lacking apparent polarity or known cellular organizers (e.g., the bacterium Staphylococcus aureus) may enable the elucidation of the primal organizational drive in biology. How does a cell choose from infinite locations in its membrane? We have discovered a structure in the S. aureus membrane that organizes processes indispensable for life and can arise spontaneously from the geometric constraints of protein complexes on membranes. Building on this finding, the most basic cellular positioning system to optimize biological processes, known molecular coordinators could introduce further levels of complexity. All life demands the temporal and spatial control of essential biological functions. In bacteria, the recent discovery of coordinating elements provides a framework to begin to explain cell growth and division. Here we present the discovery of a supramolecular structure in the membrane of the coccal bacterium Staphylococcus aureus, which leads to the formation of a large-scale pattern across the entire cell body; this has been unveiled by studying the distribution of essential proteins involved in lipid metabolism (PlsY and CdsA). The organization is found to require MreD, which determines morphology in rod-shaped cells. The distribution of protein complexes can be explained as a spontaneous pattern formation arising from the competition between the energy cost of bending that they impose on the membrane, their entropy of mixing, and the geometric constraints in the system. Our results provide evidence for the existence of a self-organized and nonpercolating molecular scaffold involving MreD as an organizer for optimal cell function and growth based on the intrinsic self-assembling properties of biological molecules

    Surfactant-free purification of membrane protein complexes from bacteria: application to the staphylococcal penicillin-binding protein complex PBP2/PBP2a

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    Surfactant-mediated removal of proteins from biomembranes invariably results in partial or complete loss of function and disassembly of multi-protein complexes. We determined the capacity of styrene-co-maleic acid (SMA) co-polymer to remove components of the cell division machinery from the membrane of drug-resistant staphylococcal cells. SMA-lipid nanoparticles solubilized FtsZ-PBP2-PBP2a complexes from intact cells, demonstrating the close physical proximity of these proteins within the lipid bilayer. Exposure of bacteria to (-)-epicatechin gallate, a polyphenolic agent that abolishes β-lactam resistance in staphylococci, disrupted the association between PBP2 and PBP2a. Thus, SMA purification provides a means to remove native integral membrane protein assemblages with minimal physical disruption and shows promise as a tool for the interrogation of molecular aspects of bacterial membrane protein structure and function

    The impact of breeding Yellow-Legged Gulls on vegetation cover and plant composition of Grey Dune habitats

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    The establishment of large populations of yellow-legged gull Larus michahellis in coastal and urban areas can lead to strong changes in vegetation cover and composition through creating physical disturbance in the vegetation and impacting the soil quality through defecation. In this study, we evaluated the effects of breeding yellow-legged gull populations on tall and short vegetation cover and plant species composition in old (occupied for 13 years) and new (occupied for 3 years) colony sites in grey dunes of the Algarve, southern Portugal. In each site, sampling plots were used to measure the percentage of vegetation cover in areas with and without breeding gulls. In the old colony site, the cover by tall vegetation was substantially reduced and the cover by short vegetation substantially increased in the areas where gulls are breeding in comparison with the adjacent areas. In the new colony sites, there were only minor differences. The increase in cover of short vegetation in the breeding area of the old colony site was mostly by nitrophilous species (Paronychia argentea and Malcolmia littorea) and should be explained by the decrease in vegetation cover of tall plant species and by feces deposition. Tall and slow-growing species Suaeda maritima and Helichrysum italicum covers were negatively affected. Our results showed that yellow-legged gulls affected vegetation cover and composition of grey dunes after 3 years of consecutive breeding, and this should be considered in the management of these habitats where breeding yellow-legged gulls are increasing.info:eu-repo/semantics/publishedVersio

    El empoderamiento productivo de la mujer como consecuencia de la Inclusión Financiera

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    The document analyzes the importance of financial inclusion and the relationship it generates with the economic development of women through productive entrepreneurship. The objective is to show the importance of access to financial services and the creation of ventures to seek gender equality, for this the profitability caused by women, the evolution of the creation of companies and their sources of financing, the barriers that are faced when initiating the ventures and the benefits that financial inclusion entails. Finally, the authors highlight good practices and public policies that promote the goals of equality and economic growth for women.El documento analiza la importancia de la inclusión financiera y la relación que genera con el desarrollo económico de la mujer a través del emprendimiento productivo. El objetivo es mostrar la importancia que produce el trabajo mancomunado entre los sectores que promuevan el acceso a servicios financieros y la creación de emprendimientos para buscar la igualdad de género, para esto se señala la rentabilidad que provocan las mujeres, la evolución de la creación de empresas y sus fuentes de financiamiento, las barreras que se enfrentan al momento de iniciar los emprendimientos y los beneficios que conlleva la inclusión financiera. Por último, los autores resaltan las buenas prácticas y políticas públicas que fomentan los objetivos de igualdad y crecimiento económico de las mujeres

    Postnatal administration of allopregnanolone modifies glutamate release but Not BDNF content in striatum samples of rats prenatally exposed to ethanol

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    Ethanol consumption during pregnancy may induce profound changes in fetal CNS development. We postulate that some of the effects of ethanol on striatal glutamatergic transmission and neurotrophin expression could be modulated by allopregnanolone, a neurosteroid modulator of GABA A receptor activity. We describe the acute pharmacological effect of allopregnanolone (65 μg/kg, s.c.) administered to juvenile male rats (day 21 of age) on the corticostriatal glutamatergic pathway, in both control and prenatally ethanol-exposed rats (two ip injections of 2.9 g/kg in 24% v/v saline solution on gestational day 8). Prenatal ethanol administration decreased the K+-induced release of glutamate regarding the control group. Interestingly, this effect was reverted by allopregnanolone. Regarding BDNF, allopregnanolone decreases the content of this neurotrophic factor in the striatum of control groups. However, both ethanol alone and ethanol plus allopregnanolone treated animals did not show any change regarding control values. We suggest that prenatal ethanol exposure may produce an alteration of GABA A receptors which blocks the GABA agonist-like effect of allopregnanolone on rapid glutamate release, thus disturbing normal neural transmission. Furthermore, the reciprocal interactions found between GABAergic neurosteroids and BDNF could underlie mechanisms operating during the neuronal plasticity of fetal development.Fil: Yunes, Roberto Miguel Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Medicas; ArgentinaFil: Estrella, Cecilia R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: García Menéndez, Sebastián Marcelo Manuel. Universidad Nacional de Cuyo. Facultad de Ciencias Medicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Lara, Hernán E.. Universidad de Chile; ChileFil: Cabrera Kreiker, Ricardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentin

    Müller cyst: report of a case in pregnancy

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    Müller cysts are alterations in the development of sexual cords and remain as malformations associated with them. They can occur in many morphological varieties. In the case of pregnancy, vaginal tumors can complicate labor because they cause obstruc-tion of the canal. During labor, these alterations can complicate the diagnosis and proper management of pregnancy. A 22-year-old female, who came to the hospital at 30.1 weeks of gestation for the first time, due to obstetric pain, vaginal tumor was detected, the patient triggered preterm labor, which did not address medical management based on oral and intravenous uteroinhibitors, so a cesarean is decided, later in the puerperium magnetic resonance was performed finding a defect in the vaginal wall, compatible with probable Müller's cyst. Due to its low frequency but high impact on pregnancy, vaginal tumors are a diagnostic and therapeutic challenge, due to their embryological origin should be detected and advise on the consequences of them. As a result, some other alterations may coexist, which is why complementary studies are essential. In the pregnancy protocol, the proper location of the cysts guides us to a specific embryological origin, as well as a preventive intervention can be planned in cases like this. If these patients are asymptomatic, surgical intervention is not required, much less during pregnancy unless an obstetric indication for interruption is determined

    Stellar Population gradients in galaxy discs from the CALIFA survey

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    While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at \sim2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&

    Non-expanded adipose stromal vascular fraction cell therapy for multiple sclerosis

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    The stromal vascular fraction (SVF) of adipose tissue is known to contain mesenchymal stem cells (MSC), T regulatory cells, endothelial precursor cells, preadipocytes, as well as anti-inflammatory M2 macrophages. Safety of autologous adipose tissue implantation is supported by extensive use of this procedure in cosmetic surgery, as well as by ongoing studies using in vitro expanded adipose derived MSC. Equine and canine studies demonstrating anti-inflammatory and regenerative effects of non-expanded SVF cells have yielded promising results. Although non-expanded SVF cells have been used successfully in accelerating healing of Crohn's fistulas, to our knowledge clinical use of these cells for systemic immune modulation has not been reported. In this communication we discuss the rationale for use of autologous SVF in treatment of multiple sclerosis and describe our experiences with three patients. Based on this rationale and initial experiences, we propose controlled trials of autologous SVF in various inflammatory conditions

    Effects of PACK guide training on the management of asthma and chronic obstructive pulmonary disease by primary care clinicians: a pragmatic cluster randomised controlled trial in Florianópolis, Brazil

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    Introduction The Practical Approach to Care Kit (PACK) guide was localised for Brazil, where primary care doctors and nurses were trained to use it. Methods Twenty-four municipal clinics in Florianópolis were randomly allocated to receive outreach training and the guide, and 24 were allocated to receive only the guide. 6666 adult patients with asthma or chronic obstructive pulmonary disease (COPD) were enrolled, and trial outcomes were measured over 12 months, using electronic medical records. The primary outcomes were composite scores of treatment changes and spirometry, and new asthma and COPD diagnosis rates. Results Asthma scores in 2437 intervention group participants were higher (74.8%, 20.4% and 4.8% with scores of 0, 1 and 2, respectively) than in 2633 control group participants (80.0%, 16.8% and 3.2%) (OR for higher score 1.32, 95% CI 1.08 to 1.61, p=0.006). Adjusted for asthma scores recorded in each clinic before training started, the OR was 1.24 (95% CI 1.03 to 1.50, p=0.022). COPD scores in 1371 intervention group participants (77.7%, 17.9% and 4.3% with scores of 0, 1 and 2) did not differ from those in 1181 control group participants (80.5%, 15.8% and 3.7%) (OR 1.21, 95% CI 0.94 to 1.55, p=0.142). Rates of new asthma and COPD diagnoses, and hospital admission, and indicators of investigation, diagnosis and treatment of comorbid cardiovascular disease, diabetes and depression, and tobacco cessation did not differ between trial arms. Conclusion PACK training increased guideline-based treatment and spirometry for asthma but did not affect COPD or comorbid conditions, or diagnosis rates
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