993 resultados para Scalar-vector-pseudoscalar potential
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Dos flebótomos atraídos pelo Proechimys iheringi numa área onde esse roedor foi achado naturalmente infectado por Leishmania mexicana ssp., 98,1% foram Lutzomyia gasparviannai, o que sugere que essa espécie não antropofílica seja o transmissor entre os roedores mas não habitualmente ao homem.
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Biological materials are increasingly used in abdominal surgery for ventral, pelvic and perineal reconstructions, especially in contaminated fields. Future applications are multi-fold and include prevention and one-step closure of infected areas. This includes prevention of abdominal, parastomal and pelvic hernia, but could also include prevention of separation of multiple anastomoses, suture- or staple-lines. Further indications could be a containment of infected and/or inflammatory areas and protection of vital implants such as vascular grafts. Reinforcement patches of high-risk anastomoses or unresectable perforation sites are possibilities at least. Current applications are based mostly on case series and better data is urgently needed. Clinical benefits need to be assessed in prospective studies to provide reliable proof of efficacy with a sufficient follow-up. Only superior results compared with standard treatment will justify the higher costs of these materials. To date, the use of biological materials is not standard and applications should be limited to case-by-case decision.
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Introduction: Calcific tendonitis of rotator cuff is observed on plainradiographs in 10% of adults, but remains asymptomatic in half thesecases. Sometimes, these calcifications induce acute flares withmassive inflammation similar to gout or CPPD crisis. Analgesics/anti-inflammatory medications are usually not sufficient to controlssymptoms in these situations. Local steroid infiltration with or withoutremoval of the calcific deposition with a needle aspiration may beuseful. A new approach could be IL-1 inhibitors. Indeed, basic calciumphosphate crystals are capable of stimulating the release of activeIL-1β in vitro. These crystals trigger IL-1β release, in an analogousmanner to MSU crystals in acute gout, suggesting that IL-1β blockademay be clinically useful.Case presentation: This report describes a 70-year old woman withacute rest pain of the right shoulder since 48 hours. On examination,we found massive limitations of active and passive movements. Thepatient evaluated, on the visual scale, her symptoms at 10/10 the nightand 5/10 the day. The radiography and showed a rounded, 8 mmcalcification in the subscapularis tendon. The ultrasound aspectrevealed a heterogeneous calcification partially non solid, surroundedby massive inflammation on Doppler. C-reactive protein anderythrocyte sedimentation rate were high (74 mg/ml, 54 mm/hour).The patient received subcutaneous injections of anakinra: 100 mgdaily for 3 days (D1-D3). We evaluated the patient in our consult at dayD1, D2, D3, D7, D16 and by phone at D70.This treatment rapidly relieved the inflammatory symptoms (within afew hours with no relapse). The mobility of the shoulder, the biologicsparameters improved and the size of the calcification as well thedegree of inflammation regressed on ultrasound after 3 days.Conclusion: This is the first report of a woman with an acute flareinduced by calcific tendonitis who received anakinra. IL-1 inhibitionmay be a therapeutic target in calcific tendonitis. To analyse thisresponse more precisely and elaborate definitive conclusions, aprospective pilot study is on-going in our ambulatory institute.
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Infective stages of Leishmania (Leishmania) amazonensis, capable of producing amastigote infections in hamster skin, were shown to be present in the experimentally infected sandfly vector Lutzomyia flaviscutellata 15, 25, 40, 49, 70, 96 and 120 hours after the flies had received their infective blood-meal. Similarly, infective stages of Leishmania (L.) chagasi were demonstrated in the experimentally infected vector Lu. longipalpis examined 38, 50, 63, 87, 110, 135, 171 and 221 hours following the infective blood-meal, by the intraperitoneal inoculation of the flagellates into hamsters. The question of whether or not transmission by the bite of the sandfly is dependent on the presence of [quot ]metacyclic[quot ] promastigotes in the mouthparts of the vector is discussed.
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The taxonomic status of three Amazonian simuliid species, Simulium guianese Wise, S. oyapockense Floch & Abonnenc and S. yarzabali Ramirez Perez is reviewed. Simulium cuasisanguineum Ramirez Perez, Yarzabal & Peterson is synonymized with S. oyapockense, and S. yarzabali is revalidated from its synonymy with S. incrustatum Lutz. The role of these three species in the transmission of human onchocerciasis and mansonelliasis in Amazonia is reviewed.
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Saliva of blood-sucking arthropods contains substances that counteract the host's hemostatic and inflammatory reactions, allowing the arthropod to locate blood and keep it flowing during the blood meal. Parasites may manipulate this system in order to achieve increased transmission, both to vertebrate and to invertebrate hosts. Additionally, salivary pharmacological substances may locally immunosupress the delivery site, allowing initial colonization of the vertebrate host by the parasite.
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Staphylococcus aureus harbors redundant adhesins mediating tissue colonization and infection. To evaluate their intrinsic role outside of the staphylococcal background, a system was designed to express them in Lactococcus lactis subsp. cremoris 1363. This bacterium is devoid of virulence factors and has a known genetic background. A new Escherichia coli-L. lactis shuttle and expression vector was constructed for this purpose. First, the high-copy-number lactococcal plasmid pIL253 was equipped with the oriColE1 origin, generating pOri253 that could replicate in E. coli. Second, the lactococcal promoters P23 or P59 were inserted at one end of the pOri253 multicloning site. Gene expression was assessed by a luciferase reporter system. The plasmid carrying P23 (named pOri23) expressed luciferase constitutively at a level 10,000 times greater than did the P59-containing plasmid. Transcription was absent in E. coli. The staphylococcal clumping factor A (clfA) gene was cloned into pOri23 and used as a model system. Lactococci carrying pOri23-clfA produced an unaltered and functional 130-kDa ClfA protein attached to their cell walls. This was indicated both by the presence of the protein in Western blots of solubilized cell walls and by the ability of ClfA-positive lactococci to clump in the presence of plasma. ClfA-positive lactococci had clumping titers (titer of 4,112) similar to those of S. aureus Newman in soluble fibrinogen and bound equally well to solid-phase fibrinogen. These experiments provide a new way to study individual staphylococcal pathogenic factors and might complement both classical knockout mutagenesis and modern in vivo expression technology and signature tag mutagenesis.
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The algorithmic approach to data modelling has developed rapidly these last years, in particular methods based on data mining and machine learning have been used in a growing number of applications. These methods follow a data-driven methodology, aiming at providing the best possible generalization and predictive abilities instead of concentrating on the properties of the data model. One of the most successful groups of such methods is known as Support Vector algorithms. Following the fruitful developments in applying Support Vector algorithms to spatial data, this paper introduces a new extension of the traditional support vector regression (SVR) algorithm. This extension allows for the simultaneous modelling of environmental data at several spatial scales. The joint influence of environmental processes presenting different patterns at different scales is here learned automatically from data, providing the optimum mixture of short and large-scale models. The method is adaptive to the spatial scale of the data. With this advantage, it can provide efficient means to model local anomalies that may typically arise in situations at an early phase of an environmental emergency. However, the proposed approach still requires some prior knowledge on the possible existence of such short-scale patterns. This is a possible limitation of the method for its implementation in early warning systems. The purpose of this paper is to present the multi-scale SVR model and to illustrate its use with an application to the mapping of Cs137 activity given the measurements taken in the region of Briansk following the Chernobyl accident.
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The author studied some protective behaviors of Biomphalaria glabrata (vertical movements, response to molluscicides and response to water currents) and demonstrated how these activities hamper the control of this snail, which is the main vector of schistosomiasis in Brazil.
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Increasingly the development of novel therapeutic strategies is taking into consideration the contribution of the intestinal microbiota to health and disease. Dysbiosis of the microbial communities colonizing the human intestinal tract has been described for a variety of chronic diseases, such as inflammatory bowel disease, obesity and asthma. In particular, reduction of several so-called probiotic species including Lactobacilli and Bifidobacteria that are generally considered to be beneficial, as well as an outgrowth of potentially pathogenic bacteria is often reported. Thus a tempting therapeutic approach is to shape the constituents of the microbiota in an attempt to restore the microbial balance towards the growth of 'health-promoting' bacterial species. A twist to this scenario is the recent discovery that the respiratory tract also harbors a microbiota under steady-state conditions. Investigators have shown that the microbial composition of the airway flora is different between healthy lungs and those with chronic lung diseases, such as asthma, chronic obstructive pulmonary disease as well as cystic fibrosis. This is an emerging field, and thus far there is very limited data showing a direct contribution of the airway microbiota to the onset and progression of disease. However, should future studies provide such evidence, the airway microbiota might soon join the intestinal microbiota as a target for therapeutic intervention. In this review, we highlight the major advances that have been made describing the microbiota in chronic lung disease and discuss current and future approaches concerning manipulation of the microbiota for the treatment and prevention of disease.
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Comparision by scanning electron microscopy (SEM) of Trypanosoma cruzi flagellates attached to the cuticle of the rectal gland of infected Dipetalogaster maxima nymphs, showed marked differences before amd after feeding. Before feeding numerous metacyclic trypomastigotes were observed among the abundant epimastigotes that formed the carpet of flagellates. On the other hand, in insects that were allowed to urinate for 24 hours after a meal, the metacyclics were scarce,indicating that they had been detached by the urine flow. An asymetric type of cell division, probably originating both an epi-and a trypomastigote, was occasionally observed. The occurrence of swellings at different levels of the flagella of epimastigotes suggests that secondary sites of attachment may be common.
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Primary sensory cortex discriminates incoming sensory information and generates multiple processing streams toward other cortical areas. However, the underlying cellular mechanisms remain unknown. Here, by making whole-cell recordings in primary somatosensory barrel cortex (S1) of behaving mice, we show that S1 neurons projecting to primary motor cortex (M1) and those projecting to secondary somatosensory cortex (S2) have distinct intrinsic membrane properties and exhibit markedly different membrane potential dynamics during behavior. Passive tactile stimulation evoked faster and larger postsynaptic potentials (PSPs) in M1-projecting neurons, rapidly driving phasic action potential firing, well-suited for stimulus detection. Repetitive active touch evoked strongly depressing PSPs and only transient firing in M1-projecting neurons. In contrast, PSP summation allowed S2-projecting neurons to robustly signal sensory information accumulated during repetitive touch, useful for encoding object features. Thus, target-specific transformation of sensory-evoked synaptic potentials by S1 projection neurons generates functionally distinct output signals for sensorimotor coordination and sensory perception.