1000 resultados para ~(266)Bh
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A new species of phlebotomine sand fly, Lutzomyia adamsi n. sp., is described and illustrated from specimens collected during August 1994, in Sandia, Department of Puno-Peru. According to the Oficina Nacional de Evaluacion de Recursos Naturales(ONERN 1976), this locality is situated in the life zone known as humid, mountain, low tropical forest (bh-MBT). Many areas in the northern part of Puno, mainly in the Inambari and Tambopata basins, are endemic to leishmaniasis. These areas are the continuation of others, largely known as "leishmaniasic" in the departments of Cusco and Madre de Dios. The morphological characteristics indicated that this species belongs to the genus Lutzomyia, subgenus Helcocyrtomyia Barretto, 1962
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Tolerance is a poorly understood phenomenon that allows bacteria exposed to a bactericidal antibiotic to stop their growth and withstand drug-induced killing. This survival ability has been implicated in antibiotic treatment failures. Here, we describe a single nucleotide mutation (tol1) in a tolerant Streptococcus gordonii strain (Tol1) that is sufficient to provide tolerance in vitro and in vivo. It induces a proline-to-arginine substitution (P483R) in the homodimerization interface of enzyme I of the sugar phosphotransferase system, resulting in diminished sugar uptake. In vitro, the susceptible wild-type (WT) and Tol1 cultures lost 4.5 and 0.6 log(10) CFU/ml, respectively, after 24 h of penicillin exposure. The introduction of tol1 into the WT (WT P483R) conferred tolerance (a loss of 0.7 log(10) CFU/ml/24 h), whereas restitution of the parent sequence in Tol1 (Tol1 R483P) restored antibiotic susceptibility. Moreover, penicillin treatment of rats in an experimental model of endocarditis showed a complete inversion in the outcome, with a failure of therapy in rats infected with WT P483R and the complete disappearance of bacteria in animals infected with Tol1 R483P.
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BACKGROUND: Recombinant human insulin-like growth factor I (rhIGF-I) is a possible disease modifying therapy for amyotrophic lateral sclerosis (ALS, which is also known as motor neuron disease (MND)). OBJECTIVES: To examine the efficacy of rhIGF-I in affecting disease progression, impact on measures of functional health status, prolonging survival and delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival in ALS. Occurrence of adverse events was also reviewed. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (21 November 2011), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to November 2011) and EMBASE (January 1980 to November 2011) and sought information from the authors of randomised clinical trials and manufacturers of rhIGF-I. SELECTION CRITERIA: We considered all randomised controlled clinical trials involving rhIGF-I treatment of adults with definite or probable ALS according to the El Escorial Criteria. The primary outcome measure was change in Appel Amyotrophic Lateral Sclerosis Rating Scale (AALSRS) total score after nine months of treatment and secondary outcome measures were change in AALSRS at 1, 2, 3, 4, 5, 6, 7, 8, 9 months, change in quality of life (Sickness Impact Profile scale), survival and adverse events. DATA COLLECTION AND ANALYSIS: Each author independently graded the risk of bias in the included studies. The lead author extracted data and the other authors checked them. We generated some missing data by making ruler measurements of data in published graphs. We collected data about adverse events from the included trials. MAIN RESULTS: We identified three randomised controlled trials (RCTs) of rhIGF-I, involving 779 participants, for inclusion in the analysis. In a European trial (183 participants) the mean difference (MD) in change in AALSRS total score after nine months was -3.30 (95% confidence interval (CI) -8.68 to 2.08). In a North American trial (266 participants), the MD after nine months was -6.00 (95% CI -10.99 to -1.01). The combined analysis from both RCTs showed a MD after nine months of -4.75 (95% CI -8.41 to -1.09), a significant difference in favour of the treated group. The secondary outcome measures showed non-significant trends favouring rhIGF-I. There was an increased risk of injection site reactions with rhIGF-I (risk ratio 1.26, 95% CI 1.04 to 1.54). . A second North American trial (330 participants) used a novel primary end point involving manual muscle strength testing. No differences were demonstrated between the treated and placebo groups in this study. All three trials were at high risk of bias. AUTHORS' CONCLUSIONS: Meta-analysis revealed a significant difference in favour of rhIGF-I treatment; however, the quality of the evidence from the two included trials was low. A third study showed no difference between treatment and placebo. There is no evidence for increase in survival with IGF1. All three included trials were at high risk of bias.
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Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.
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Using cryo-electron microscopy we reconstructed the three-dimensional trajectories adopted in cryovitrified solutions by double-stranded DNA molecules in which the backbone of one strand lacked a phosphate at regular intervals of 20 nucleotides. The shape of such nicked DNA molecules was compared with that of DNA molecules with exactly the same sequence but without any single-stranded scissions. Upon changing the salt concentration we observed opposite effects of charge neutralization on nicked and non-nicked DNA. In low salt solutions (10 mM Tris-HCl, 10 mM NaCl) the applied dense nicking caused ca 3.5-fold reduction of the DNA persistence length as compared with non-nicked DNA. Upon increasing the salt concentration (to 150 mM NaCl and 10 mM MgCl2) the persistence length of non-nicked DNA appreciably decreased while that of nicked DNA molecules increased by a factor of 2.
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The water rat, Nectomys squamipes, closely involved in schistosomiasis transmission in Brazil, has been found naturally infected simultaneously by Schistosoma mansoni and Echinostoma paraensei. Laboratory experiments were conducted to verify parasitic interaction in concurrent infection. It was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with E. paraensei. Rodents were divided into three groups in each replication. A wild strain recently isolated from Sumidouro, RJ, and a laboratory strain of S. mansoni from Belo Horizonte (BH) was used. Rats infected with E. paraensei were challenged 4 weeks later with S. mansoni and mice 2 or 6 weeks after the infection with S. mansoni. Necropsy took place 8 weeks following S. mansoni infection. The N. squamipes treatment groups challenged with S. mansoni RJ strain showed a significant decrease (80 and 65%) in the S. mansoni parasite load when compared with their respective control groups. There was a significant change or no change in the hosts challenged with the BH strain. The persistence time of E. paraensei within host was extended in relation to control groups, with a consequent enhancement of the number of recovered worm. An E. paraensei strain-specific influence on S. mansoni parasitism is reported. This paper presents some experimental data about this interaction in N. squamipes and Mus musculus.
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La mecanización integral de la cosecha se reduce todavía a un número limitado de explotaciones, aunque cada día son más las plantaciones en las que se utilizan vibradores en la cosecha. La utilización de cosechadoras está reservada a explotaciones superiores a las 20 ha y se suele recurrir a vibradores de ramas mientras los árboles no alcanzan la envergadura de adultos. Una correcta cosecha se suelen realizar en dos pasadas y en pocas explotaciones se utilizan productos para la maduración artificial. Prácticamente la mayoría de las nuevas plantaciones de nogal disponen de sistemas de secado y acondicionado de las nueces, los productores son conscientes de la importancia del tratamiento de post-cosecha que, sin duda, marca la calidad final de la producción y con ella el precio de la nuez. En la misma explotación las nueces son peladas, lavadas, secadas y muy habitualmente calibradas y envasadas. Las nueces se secan entre 10-12% bh. en cáscara, y hasta 5-6% bh. en grano, utilizando secadores de aire insuflado por la base, los tradicionales de ‘falso fondo’ son los más habituales.
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The effects of a protein-restricted diet (8% protein, 81% carbohydrate and 11% lipids) on Schistosoma mansoni infectivity, fecal egg excretion and intestinal egg distribution in Swiss (SW) mice were studied. Pregnant mice received a deficient diet from the middle of gestation until delivery. Seven-days-old mice were exposed to 50 cercariae (BH strain, Brazil). Offspring mice had a free access to the deficient diet since lactation until adulthood. The controls were fed with a commercial mice diet. A parasitological examination was performed between six and eight weeks post-infection while both groups were necropsied one week later. Mice on the experimental diet showed a significant loss in body weight. There was no significant difference (p > 0.05) in pre-patent period, kinetics of egg excretion and worm recovery from mice on either diet. Significant differences (p < 0.05) were found concerning to the percentage of deposited eggs in the distal segment of the small intestine from hosts on the experimental diet.Our data suggest that experimental malnutrition induced for a long term has no detrimental effect on the acute schistosomiais infection in SW mice.
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BACKGROUND: : Most of the existing research relating to the life courses of people with psychiatric symptoms focuses on the occurrence and the impact of non-normative events on the onsets of crises; it usually disregards the more regular dimensions of life, such as work, family and intimate partnerships that may be related to the timing and seriousness of psychiatric problems. An additional reason for empirically addressing life trajectories of individuals with psychiatric problems relates to recent changes of family and occupational trajectories in relation to societal trends such as individualization and pluralization of life courses.¦AIM: : This paper explores the life trajectories of 86 individuals under clinical supervision and proposes a typology of their occupational, co-residence and intimacy trajectories. The results are discussed in light of the life-course paradigm.¦METHOD: : A multidimensional optimal matching analysis was performed on a sample of 86 individuals under clinical supervision to create a typology of trajectories. The influence of these trajectories on psychiatric disorders, evaluated using a SCL-90-R questionnaire, was then assessed using linear regression modelling.¦RESULTS: : The typologies of trajectories showed that the patients developed a diversity of life trajectories. Individuals who have developed a standard life course with few institutionalization periods reported more symptoms and distress than individuals with an institutionalized life trajectory.¦CONCLUSION: : The results of this study stress that psychiatric patients are social actors who are influenced by society at large and its ongoing process of change. Therefore, it is essential to take into account the diversity of occupational and family trajectories when dealing with individuals in therapeutic settings.
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A number of recent studies revealed that epigenetic modifications play a central role in the regulation of lipid and of other metabolic pathways such as cholesterol homeostasis, bile acid synthesis, glucose and energy metabolism. Epigenetics refers to aspects of genome functions regulated in a DNA sequence-independent fashion. Chromatin structure is controlled by epigenetic mechanisms through DNA methylation and histone modifications. The main modifications are histone acetylation and deacetylation on specific lysine residues operated by two different classes of enzymes: Histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. The interaction between these enzymes and histones can activate or repress gene transcription: Histone acetylation opens and activates chromatin, while deacetylation of histones and DNA methylation compact chromatin making it transcriptionally silent. The new evidences on the importance of HDACs in the regulation of lipid and other metabolic pathways will open new perspectives in the comprehension of the pathophysiology of metabolic disorders.
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Lectins/carbohydrate binding can be involved in the Schistosoma mansoni recognition and activation of the Biomphalaria hemocytes. Therefore, expression of lectin ligands on Biomphalaria hemocytes would be associated with snail resistance against S. mansoni infection. To test this hypothesis, circulating hemocytes were isolated from B. glabrata BH (snail strain highy susceptible to S. mansoni), B. tenagophila Cabo Frio (moderate susceptibility), and B. tenagophila Taim (completely resistant strains), labelled with FITC conjugated lectins (ConA, PNA, SBA, and WGA) and analyzed under fluorescence microscopy. The results demonstrated that although lectin-labelled hemocytes were detected in hemolymph of all snail species tested, circulating hemocytes from both strains of B. tenagophila showed a larger number of lectin-labelled cells than B. glabrata. Moreover, most of circulating hemocytes of B. tenagophila were intensively labelled by lectins PNA-FITC and WGA-FITC, while in B. glabrata small hemocytes were labeled mainly by ConA. Upon S. mansoni infection, lectin-labelled hemocytes almost disappeared from the hemolymph of Taim and accumulated in B. glabrata BH. The role of lectins/carbohydrate binding in resistance of B. tengophila infection to S. mansoni is still not fully understood, but the data suggest that there may be a correlation to its presence with susceptibility or resistance to the parasite.
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As well as malaria and yellow fever, schistosomiasis is one of the main endemic diseases associated to environments which suffered some impact related to the development of great economic projects, as for example the construction of hydroelectric power stations. Aiming to investigate the occurrence and distribution of freshwater snails of medical and veterinary importance in the area which suffered impact from the Manso hydroelectric power station a survey was performed during the period of 2002 to 2003 and revealed the occurrence of populations of Biomphalaria amazonica and Biomphalaria occidentalis. Studies on parasite-mollusc compatibility were undertaken using five B. amazonica colonies (Barão de Melgaço, Poconé, Santo Antônio do Leverger, and Chapada dos Guimarães, in the Manso and Casca rivers), and four B. occidentalis colonies (Cuiabá, Santo Antônio do Leverger, and Chapada dos Guimarães, in the Água Fria district and Casca river) were exposed to miracidia of Schistosoma mansoni. Of 257 snails of B. amazonica used, 17 became infected (infection index of 6.61%) and all specimens of B. occidentalis proved unsusceptible. According to the strains used, of the 158 snails exposed to BH miracidia, 6 became infected (3.79%); of the 44 exposed to SJ miracidia, 6 became infected (13.63%); and of the 55 snails of B. amazonica exposed to EC miracidia, 5 became infected (9.09%). These results point out the low possibility of introduction of schistosomiasis in those areas, but we believe it can not be discarded as due the presence of B. amazonica.
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High-fat diets induce weight gain and fatty liver in wild-type mice. Schistosomiasis mansoni infection also promotes hepatic injury. This study was designed to quantify hepatic alterations in schistosomiasis mansoni-infected mice fed a high fat-rich chow compared to mice fed a standard rodent chow, using stereology. Female SW mice fed each either high-fat diet (29% lipids) or standard chow (12% lipids) over 8 months, and then were infected with Schistosoma mansoni cercariae. Four experimental groups were studied: infected mice fed a high-fat diet (IHFC) or standard chow (ISC), uninfected mice fed a high-fat diet (HFC) or standard chow (SC). Mice were sacrificed during early infection (9 weeks from exposure). The following hepatic biometry and the stereology parameters were determined: volume density (hepatocytes [h], sinusoids [s], steatosis [st] and hepatic fibrosis [hf]); numerical density (hepatocyte nuclei - Nv[h]); absolute number of total hepatocyte N[h], normal hepatocyte N[nh], and binucleated hepatocyte N[bh], percentage of normal hepatocyte P[nh] and binucleated hepatocyte P[bh]. IHFC and HFC groups exhibited TC, HDL-C, LDL-C, and body mass significantly greater (p < 0.05) than control group. No significant differences were found regards liver volume (p = 0.07). Significant differences were observed regards P[nh] (p = 0.0045), P[bh] (p = 0.0045), Nv[h] (p = 0.0006), N[h] (p = 0.0125), N[bh] (p = 0.0164) and N[nh] (p = 0.0078). IHFC mice group presented 29% of binucleated hepatocytes compared to HFC group (19%), ISC group (17%) and SC (6%). Volume density was significantly different between groups: Vv[h] (p = 0.0052), Vv[s] (p = 0.0025), Vv[st] (p = 0.0004), and Vv[hf] (p = 0.0007). In conclusion, schistosomiasis mansoni infection with concurrent high-fat diet promotes intensive quantitative changes in hepatic structure, contributing to an increasing on hepatic regeneration.
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Cette recherche s'intéresse aux témoins glaciaires des Chablais dans quatre de leurs dimensions : géopatrimoine, connaissance objective, inventaire de géosites et valorisation. En 2009, débutait le projet 123 Chablais, pour une durée de quatre ans. Ce projet, élaboré dans le cadre du programme Interreg IV France-Suisse, avait pour but de dynamiser le développement économique local en s'appuyant sur les patrimoines régionaux. Le géopatrimoine, identifié comme une de ces ressources, faisait donc l'objet de plusieurs actions, dont cette recherche. Le premier objectif de ce travail était d'acquérir une vision synthétique des témoins glaciaires locaux et d'en améliorer la connaissance, notamment, leur chronologie. Une série de datations par isotopes cosmogéniques produits in situ a permis de compléter des données disponibles pour deux stades glaciaires bien identifiés: le dernier maximum glaciaire (LGM) et un stade de retrait du glacier du Rhône (le stade de Monthey). Le second objectif était centré sur les processus d'identification et d'inventaire des géosites glaciaires. L'analyse des résultats de l'inventaire a fait apparaître quelques caractéristiques du patrimoine glaciaire chablaisien, discret, diversifié, et comportant deux spécificités exploitables dans le cadre d'une médiation scientifique : son statut de « berceau de la théorie glaciaire » et ses liens étroits avec des activités de la vie quotidienne, en tant que matière première, support de loisir ou facteur de risque. Finalement, cette recherche a débouché sur l'élaboration d'une exposition itinérante sur le patrimoine glaciaire des Chablais.
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Résumé Etant une importante source d'énergie, les plantes sont constamment attaquées par des pathogènes. Ne pouvant se mouvoir, elles ont développé des systèmes de défense sophistiqués afin de lutter contre ces prédateurs. Parmi ces systèmes, les voies de signalisation mettant en jeu des éliciteurs endog8nes tels que les jasmonates permettent d'induire la production de protéines de défense telles que les protéines dites "liées à la pathogénèse". Les gènes codant pour ces protéines appartiennent à des familles multigéniques. Le premier but de cette thèse est d'évaluer le nombre de ces gènes dans le génome d'Arabidopsis thaliana et d'estimer la part de ce système de défense, dépendant de la voie de signalisation des jasmonates. Nous avons défini un cluster de seulement 1S gènes sur 266, "liés à la pathogénèse", exclusivement régulés par les jasmonates. De multiples membres des familles des lectines de type jacaline et des inhibiteurs de trypsines semblent dépendre du jasmonate. Présente dans tous les systèmes immunitaires des eucaryotes, la famille des défensines est une famille très intéressante. Chez Arabidopsis thaliana, 317 protéines similaires aux défensines ont été définies, cependant seulement 15 défensines (PDF) sont bien annotées. Ces 15 défensines sont séparées en deux groupes dont un semble avoir évolué plus récemment. Le second but de cette thèse est d'étudier ce groupe de défensines à l'aide de la bioinformatique et des techniques de biologie moléculaire (gêne rapporteur, PCR en temps réel). Nous avons montré que ce groupe contenait une défensine acide intéressante, PDF1.5, qui semblait avoir subi une sélection positive. Cette protéine n'avait encore jamais été étudiée. Contrairement à ce que nous pensions, nous avons établi que cette protéine pouvait avoir une activité biologique liée à la défense. Ce travail de thèse a permis de préciser le nombre de gènes "liées à la pathogénèse" induits par la voie des jasmonates et d'apporter des éléments de réponse sur la question de la redondance des gènes de défense. En conclusion, même si de nombreuses familles de gènes intervenant dans la défense sont bien définies chez Arabidopsis, il reste encore de nombreuses études à faire sur chacun de ces membres. Abstract Being an important source of energy, plants are constantly attacked by herbivores and pathogens. As sessile organisms, they have developed sophisticated defense responses to cope with attack. Among these responses, signalling pathways, using endogenous elicitors including jasmonates (JA), allow the plant to induce the production of defense proteins such as pathogenesis-related (PR) proteins. The genes encoding these proteins belong to multigenic families. The first goal of this thesis was to evaluate the number of PR genes in the genome of Arabidopsis thaliana and estimate how much of this plant defense system was dependent on the jasmonate signaling pathway in leaves. Surprisingly a cluster of only 1S genes out of 2ó6 PR genes was exclusively regulated by JA. Multiple members of the jacalin lectin and trypsin inhibitor gene families were shown to be regulated by JA. Present in all eukaryotic immune systems, defensins are an attractive PR family to study. In Arabidopsis thaliana, 317 defensin-related proteins have been found but just 1S defensins (i.e. PDF family) are well annotated. These defensins are split into 2 groups. One of these groups may have appeared and diversified recently. The second goal of this thesis was to study this defensin gene group combining bioinformatic, reporter gene and quantitative PCR techniques. We have shown that this group contains an interesting acidic defensin, PDF1.S, which seems to have undergone positive selection. No information was known on this protein. We have established that this protein may have a biological activity in plant defense. This thesis allowed us to define the number of PR genes induced by the jasmonate pathway and gave initial leads to explain the redundancy of the PR genes in the genome of Arabidopsis. In conclusion, even if many defense gene families are already defined in the Arabidopsis genome, much work remains to be done on individual members.