459 research outputs found

    Tungiasis: a poorly-known diagnosis in Europe. Two paradigmatic cases from Portugal

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    Tungiasis is a cutaneous parasitosis caused by infestation of the skin by gravid fleas of the genus Tunga, mainly Tunga penetrans. This flea is very common in tropical and subtropical regions of the globe, but not in Europe. The infestation is acquired by walking barefoot or lying in places where the flea is present, usually beaches or sandy soils. We report two unrelated cases of imported tungiasis in Portugal that presented to our clinic in the same week. We draw attention to one of the most common dermatological diseases in travelers returning from tropical countries, the diagnosis of which is primarily clinical but nonetheless is largely unfamiliar to clinicians attending those patients.info:eu-repo/semantics/publishedVersio

    Mycoplasma pneumoniae-induced rash and mucositis: a recently described entity

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    Mycoplasmapneumoniae is a common cause of respiratory infections. Although most cases are mild, some patients have extrapulmonary complications including mucocutaneous eruptions including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and erythemamultiforme (EM). Recently, a new entity, called M. pneumoniae-induced rash and mucositis (MIRM) was described. The authors present a clinical case difficult to classify attending to the classical classification of epidermolytic syndromes that meets the criteria proposed for the diagnosis of MIRM. The mucocutaneous disease associated with M. pneumoniae presents predominant mucositis, with scarce or absent cutaneous involvement. Because of the distinct morphology, pathophysiology and benign clinical course, MIRM should be considered as a new entity, distinct from SJS/TEN and EM.info:eu-repo/semantics/publishedVersio

    Cannabis arteritis: ever more important to consider

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    Cannabis arteritis (CA) is a major and underdiagnosed cause of peripheral arterial disease in young patients. A 34-year-old man, daily smoker of 20 cigarettes and two cannabis cigarettes for 14 years, presented with a necrotic plaque of left hallux for 3 weeks. The Doppler ultrasound and angiography were compatible with severe Buerger's disease. Submitted to a revascularisation procedure and hypocoagulation with rivaroxaban. He had ceased smoking but maintained consumption of cannabis. Owing to the persistence of distal necrosis, amputation of the hallux was performed with good evolution. CA is a subtype of Buerger's disease. It is poorly known but increasingly prevalent and manifests in cannabis users regardless of tobacco use. The drug is considered at least a cofactor of the arteriopathy. The most effective treatment is cessation of consumption. Being cannabis one of the most consumed drugs, its mandatory to ask about its use in all young patients with arteriopathy.info:eu-repo/semantics/publishedVersio

    Do mutual funds have consistency in their performance?

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    Using a comprehensive data set of 714 Chinese mutual funds from 2004 to 2015, the study investigates these funds’ performance persistence by using the Capital Asset Pricing model, the Fama-French three-factor model and the Carhart Four-factor model. For persistence analysis, we categorize mutual funds into eight octiles based on their one year lagged performance and then observe their performance for the subsequent 12 months. We also apply Cross-Product Ratio technique to assess the performance persistence in these Chinese funds. The study finds no significant evidence of persis- tence in the performance of the mutual funds. Winner (loser) funds do not continue to be winner (loser) funds in the subsequent time period. These findings suggest that future performance of funds cannot be predicted based on their past performance.info:eu-repo/semantics/publishedVersio

    Techniques for Arbuscular Mycorrhiza Inoculum Reduction

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    It is well established that arbuscular mycorrhizal (AM) fungi can play a significant role in sustainable crop production and environmental conservation. With the increasing awareness of the ecological significance of mycorrhizas and their diversity, research needs to be directed away from simple records of their occurrence or casual speculation of their function (Smith and Read 1997). Rather, the need is for empirical studies and investigations of the quantitative aspects of the distribution of different types and their contribution to the function of ecosystems. There is no such thing as a fungal effect or a plant effect, but there is an interaction between both symbionts. This results from the AM fungi and plant community size and structure, soil and climatic conditions, and the interplay between all these factors (Kahiluoto et al. 2000). Consequently, it is readily understood that it is the problems associated with methodology that limit our understanding of the functioning and effects of AM fungi within field communities. Given the ubiquous presence of AM fungi, a major constraint to the evaluation of the activity of AM colonisation has been the need to account for the indigenous soil native inoculum. This has to be controlled (i.e. reduced or eliminated) if we are to obtain a true control treatment for analysis of arbuscular mycorrhizas in natural substrates. There are various procedures possible for achieving such an objective, and the purpose of this chapter is to provide details of a number of techniques and present some evaluation of their advantages and disadvantages. Although there have been a large number of experiments to investigated the effectiveness of different sterilization procedures for reducing pathogenic soil fungi, little information is available on their impact on beneficial organisms such as AM fungi. Furthermore, some of the techniques have been shown to affect physical and chemical soil characteristics as well as eliminate soil microorganisms that can interfere with the development of mycorrhizas, and this creates difficulties in the interpretation of results simply in terms of possible mycorrhizal activity. An important subject is the differentiation of methods that involve sterilization from those focussed on indigenous inoculum reduction. Soil sterilization aims to destroy or eliminate microbial cells while maintaining the existing chemical and physical characteristics of the soil (Wolf and Skipper 1994). Consequently, it is often used for experiments focussed on specific AM fungi, or to establish a negative control in some other types of study. In contrast, the purpose of inoculum reduction techniques is to create a perturbation that will interfere with mycorrhizal formation, although not necessarily eliminating any component group within the inoculum. Such an approach allows the establishment of different degrees of mycorrhizal formation between treatments and the study of relative effects. Frequently the basic techniques used to achieve complete sterilization or just an inoculum reduction may be similar but the desired outcome is accomplished by adjustments of the dosage or intensity of the treatment. The ultimate choice of methodology for establishing an adequate non-mycorrhizal control depends on the design of the particular experiments, the facilities available and the amount of soil requiring treatment

    2, 3-Di-O-sulfo glucuronic acid: an unmodified and unusual residue in a highly sulfated chondroitin sulfate from Litopenaeus vannamei

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    The occurrence of a natural and unmodified highly sulfated chondroitin sulfate from Litopenaeus vannamei heads (sCS) is herein reported. Its partial digestion by Chondroitinases AC and ABC together with its electrophoretic migration profile revealed it as a highly sulfated chondroitin sulfate despite its average molecular weight being similar to CSA. Using orthogonal 1D/2D NMR experiments, the anomeric signals (δ 4.62/106.0) corresponding to unusual 2,3-di-O-Sulfo-GlcA (∼36%), U33S (δ 4.42/84.1, ∼63%) and U22S (4.12/80.1, ∼50%) substitutions were confirmed. In addition, non-sulfated GlcA (δ 4.5/106.3) linked to 4-O- (A14S, 36%) or 6-O-Sulfo (A16S, 28%) GalNAc (δ 4.64/103.5) was observed. Although the biological role of sCS in shrimp is unknown, its influence on hemostasis was also demonstrated. The sCS identification brings to light new questions about the hierarchical model of GAGs biosynthesis and contributes to the better understanding of the subtle relationship between GAGs structure and function

    Anti-inflammatory and analgesic potential of hydrolyzed extract of Agave sisalana Perrine ex Engelm., Asparagaceae

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    The hemolytic, anti-inflammatory and antinociceptive properties from hydrolyzed extract Agave sisalana Perrine ex Engelm., Asparagaceae (HEAS) was evaluated classic inflammation models. Male Swiss mice and male Wistars rats received HEAS (500 mg/kg) in two administration p.o. and i.p. in saline solution 0.9%. The acid hydrolysis inhibited the hemolytic action of saponins due to the retreat of side chain sugar. The treatment of the ear induced oedema by xylene with HEAS significantly reduced in two routes 13 +/- 1.5 and 10 +/- 0.63 mg, respectively, p.o. and i.p., in comparison with controls 27 1.5 saline and 13.5 +/- 1.2 AAS. The HEAS also diminished edema induced by carrageenin 43 +/- 1.58 mg (p.o.) and 17 +/- 1.26 mg (i.p.), when compared with control groups 52 +/- 1.58 mg (saline) and 10.05 +/- 1.58 (indomethacin). HEAS showed analgesic effects in abdominal constrictions 30.7% (p.o.), 88.7% (i.p.) comparable to that produced by (AAS) 70.6%. However in granuloma cotton pellet a chronic model of inflammation just the i.p. pathway decreased granulomatous tissue (20.4 +/- 1.32 mg) compared with controls 30.5 +/- 2.53 mg (saline) and 20.2 +/- 2.18 mg (dexamethasone). These data suggest that HEAS has anti-inflammatory and analgesic activity on acute and chronic processes.20337638

    Agronomic Management of Indigenous Mycorrhizas

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    Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production
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