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Environmental agencies around the world have adopted policies to manage e-waste and reduce the negative environmental impacts associated with its collection, sorting, dismantling, and recycling. In many OECD countries, where adequate policies and processing technologies exist, those who manage extended producer responsibility programs claim performance challenges due to competition from various actors collecting and managing e-waste "under the radar". While the material and economic losses attributed to such informal activities have been estimated by previous research, a detailed understanding of who is involved in these activities, why and how they operate, and with what social and environmental impacts, is often lacking. Our research offers an in-depth investigation into Montréal's informal e-waste flows. Whereas e-waste research and advocacy posit a dichotomy between "formal" and "informal" e-waste flows, our research reveals a more nuanced situation, with no water-tight separation between these flows. Formal and informal flows are often blurred, and change over time; and many actors are involved in both formal and informal activities. We reveal mechanisms whereby actors inadvertently contribute to informal activities because of inadequate incentives, limited program scope, reuse, parts harvesting, and documentation issues. This nuanced understanding helps identify policy loopholes, program shortcomings, and strategies for more sustainable e-waste flows, taking account of more ambitious circularity objectives and a just transition.
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Resíduo Eletrônico , Gerenciamento de Resíduos , ReciclagemRESUMO
Phelipanche ramosa is a major root-holoparasitic damaging weed characterized by a broad host range, including numerous Fabaceae species. In France, the agricultural threat posed by P. ramosa has increased over two decades due to the appearance of a genetically differentiated pathovar presenting a clear host specificity for oilseed rape. The new pathovar has led to a massive expansion of P. ramosa in oilseed rape fields. The germination rate of P. ramosa seeds is currently known to vary among P. ramosa pathovars and host species. However, only a few studies have investigated whether phylogenetic relatedness among potential host species is a predictor of the ability of these species to induce the seed germination of parasitic weeds by testing for phylogenetic signal. We focused on a set of 12 Fabaceae species and we assessed the rate of induction of seed germination by these species for two pathovars based on in vitro co-cultivation experiments. All Fabaceae species tested induced the germination of P. ramosa seeds. The germination rate of P. ramosa seeds varied between Fabaceae species and tribes studied, while pathovars appeared non-influential. Considering oilseed rape as a reference species, we also highlighted a significant phylogenetic signal. Phylogenetically related species therefore showed more similar rates of induction of seed germination than species drawn at random from a phylogenetic tree. In in vitro conditions, only Lotus corniculatus induced a significantly higher germination rate than oilseed rape, and could potentially be used as a catch crop after confirmation of these results under field conditions.
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Fabaceae/parasitologia , Germinação , Orobanchaceae/fisiologia , Sementes/crescimento & desenvolvimento , Fabaceae/classificação , Fabaceae/fisiologia , Orobanchaceae/crescimento & desenvolvimento , Filogenia , Plantas Daninhas , Especificidade da EspécieRESUMO
Phelipanche ramosa is a parasitic plant that infects numerous crops worldwide. In Western Europe it recently expanded to a new host crop, oilseed rape, in which it can cause severe yield losses. We developed 13 microsatellite markers for P. ramosa using next-generation 454 sequencing data. The polymorphism at each locus was assessed in a sample of 96 individuals collected in France within 6 fields cultivated with tobacco, hemp or oilseed rape. Two loci were monomorphic. At the other 11 loci, the number of alleles and the expected heterozygosity ranged from 3 to 6 and from 0.31 to 0.60, respectively. Genetic diversity within each cultivated field was very low. The host crop from which individuals were collected was the key factor structuring genetic variation. Individuals collected on oilseed rape were strongly differentiated from individuals collected on hemp or tobacco, which suggests that P. ramosa infecting oilseed rape forms a genetically diverged race. The microsatellites we developed will be useful for population genetics studies and for elucidating host-associated genetic divergence in P. ramosa.
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Especiação Genética , Repetições de Microssatélites , Orobanche/genética , Produtos Agrícolas , Marcadores Genéticos , Especificidade de Hospedeiro/genéticaRESUMO
Among the alternatives to synthetic plant protection products, biocontrol appears as a promising method. This review reports on the diversity of fungal secondary metabolites phytotoxic to weeds and on the approach generally used to extract, characterize, identify and exploit them for weed management. The 183 phytotoxic fungal secondary metabolites discussed in this review fall into five main classes of molecules: 61 polyketides, 53 terpenoids, 36 nitrogenous metabolites, 18 phenols and phenolic acids, and 15 miscellaneous. They are mainly produced by the genera Drechslera, Fusarium and Alternaria. The phytotoxic effects, more often described by the symptoms they produce on plants than by their mode of action, range from inhibition of germination to inhibition of root and vegetative growth, including tissue and organ alterations. The biochemical characterization of fungal secondary metabolites requires expertise and tools to carry out fungal cultivation and metabolite extraction, phytotoxicity tests, purification and fractionation of the extracts, and chemical identification procedures. Phytotoxicity tests are mainly carried out under controlled laboratory conditions (not always on whole plants), while effectiveness against targeted weeds and environmental impacts must be assessed in greenhouses and open fields. These steps are necessary for the formulation of effective, environment-friendly fungal secondary metabolites-derived bioherbicides using new technologies such as nanomaterials. © 2023 Society of Chemical Industry.
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Alcaloides , Herbicidas , Fungos Mitospóricos , Herbicidas/química , Plantas Daninhas , Alcaloides/farmacologia , Extratos Vegetais/farmacologiaRESUMO
BACKGROUND: The treatment landscape for relapsing multiple sclerosis (MS) has changed dramatically in recent decades, including an increasing number of high-efficacy disease-modifying therapies (DMTs) with varied administration and monitoring requirements. Coupled with greater focus on earlier treatment, these factors have resulted in stretching of the capacity of MS specialist services and allied healthcare professionals (HCPs). To assist with the effective planning of MS services in the UK NHS, this study quantified the administration and monitoring time burden associated with high-efficacy DMTs (alemtuzumab, cladribine tablets, fingolimod, natalizumab, and ocrelizumab) for relapsing MS. METHODS: A Time and Motion (T&M) study was conducted across four MS centres in the UK, over 3-4 months per centre (Aug 2019-Feb 2021). Time dedicated by HCPs (including but not limited to neurologists, MS specialist nurses, infusion nurses, and healthcare assistants) to pre-specified drug administration and monitoring activities, elicited during pre-study interviews at each centre, was assessed for each of the selected DMTs. Administration activities included: installing peripheral access; pre-medication administration (if needed); preparing drug for infusion; infusion initiation, monitoring, and disconnection; and patient monitoring post-infusion. Monitoring activities included: booking appointments for blood draws; blood draw; retrieval and review of blood results; maintaining blood records and follow-up with the patient; checking availability of MRI results and follow-up with the patient; booking appointments for neurologist or nurse consultations; and checking patient files prior to clinic visits. A T&M model was built using observational T&M study results, data obtained through pre-study interviews, as well as stipulated monitoring intervals from relevant Summaries of Product Characteristics for the selected DMTs, to estimate active HCP time with each DMT, extrapolated over a period of 4 years per-patient. RESULTS: For oral DMTs, projected total active HCP time (monitoring only) per-patient over 4 years was 14.7 h for cladribine tablets and 19.2 h for fingolimod. For infused DMTs, total time (administration and monitoring) for alemtuzumab was 37.7 h (6.0 and 31.6 h, respectively), 48.1 h for natalizumab (17.4 and 30.8 h, respectively), and 23.5 h for ocrelizumab (6.1 and 17.4 h, respectively). CONCLUSIONS: While active HCP time varied across centres, infused DMTs were projected to require the greatest amount of HCP time associated with administration and monitoring over 4 years versus oral DMTs. These findings may assist MS-specific HCPs in planning and delivering the equitable provision of DMT services for patients with relapsing MS.
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Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Humanos , Esclerose Múltipla/tratamento farmacológico , Cloridrato de Fingolimode/uso terapêutico , Imunossupressores/uso terapêutico , Cladribina/uso terapêutico , Natalizumab/uso terapêutico , Alemtuzumab/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Estudos de Tempo e Movimento , Reino Unido , ComprimidosRESUMO
Branched broomrape, Phelipanche ramosa (L.) Pomel, is a globally distributed parasitic weed of economic importance. In Europe, where it is native, it can infest several crops, notably tomato, tobacco, and hemp. In western France, it has recently adapted to a new host crop, oilseed rape, causing substantial damage. The aim of this study was to investigate the evolutionary relationships and genetic differentiation among P. ramosa populations infesting different hosts. We collected 1611 P. ramosa samples from 109 fields cultivated with six different crops (oilseed rape, tobacco, hemp, tomato, lentil, and celery) and distributed among six European countries. All samples were genotyped for ten microsatellite loci and a subset of samples was sequenced for two nuclear genes and two chloroplast genes. Genetic differentiation among populations was high (F ST = 0.807) and mainly driven by differentiation among different host crops, with no significant geographic structure. Genetic structure analysis identified up to seven biologically meaningful clusters that matched with host crops of origin. Reconstructed networks of sequence haplotypes and multilocus SSR genotypes showed a large genetic divergence between samples collected on oilseed rape and samples collected on other crops. The phylogeny inferred from DNA sequences placed samples collected from oilseed rape as a basal lineage. Approximate Bayesian Computations were used to compare different evolutionary scenarios of divergence among the three main genetic clusters, associated, respectively, with oilseed rape, tobacco, and hemp as host crops. The best-supported scenario indicated that P. ramosa infesting oilseed rape derived recently from an ancient, unknown lineage. Our results suggest that a more complete description of the genetic diversity of P. ramosa is still needed to uncover the likely source of the recent adaptation to oilseed rape and to anticipate future new host shifts.
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Interactions among plants have been long recognized as a major force driving plant community dynamics and crop yield. Surprisingly, our knowledge of the ecological genetics associated with variation of plant-plant interactions remains limited. In this opinion article by scientists from complementary disciplines, the international PLANTCOM network identified four timely questions to foster a better understanding of the mechanisms mediating plant assemblages. We propose that by identifying the key relationships among phenotypic traits involved in plant-plant interactions and the underlying adaptive genetic and molecular pathways, while considering environmental fluctuations at diverse spatial and time scales, we can improve predictions of genotype-by-genotype-by-environment interactions and modeling of productive and stable plant assemblages in wild habitats and crop fields.
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Ecossistema , Plantas , Genótipo , Fenótipo , Plantas/genéticaRESUMO
The properties of oxide dispersion-strengthened steels are highly dependent on the nature and size distribution of their constituting nano-oxide precipitates. A fine control of the processes of synthesis would enable the optimization of pertinent properties for use in various energy systems. This control, however, requires knowledge of the precise mechanisms of nucleation and growth of the nanoprecipitates, which are still a matter of debate. In the present study, nano-oxide precipitates were produced via the implantation of Y, Ti, and O ions in two different sequential orders in an Fe-10%Cr matrix that was subsequently thermally annealed. The results show that the oxides that precipitate are not necessarily favoured thermodynamically, but rather result from complex kinetics aspects related to the interaction between the implanted elements and induced defects. When Y is implanted first, the formation of nanoprecipitates with characteristics similar to those in conventionally produced ODS steels, especially with a core/shell structure, is evidenced. In contrast, when implantation starts with Ti, the precipitation of yttria during subsequent high-temperature annealing is totally suppressed, and corundum Cr2O3 precipitates instead. Moreover, the systematic involvement of {110} matrix planes in orientation relationships with the precipitates, independently of the precipitate nature, suggests matrix restriction effects on the early stages of precipitation.
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Branched broomrape (Phelipanche ramosa (L.) Pomel) is an achlorophyllous root parasitic plant with a wide host range. Its complex management is leading to the abandonment of tobacco or oilseed rape cultivation in the most affected regions in France. Among broomrape regulation factors, soil microorganisms such as fungi seem to be a relevant biocontrol lever. The aim of this work was to detect potential mycoherbicides among fungal endophytic colonizers of P. ramosa parasitizing tobacco. Our hypothesis was that both the inhibitory of broomrape seed germination and the necrotic activities are characteristic of the fungal isolates whatever their taxonomic position. To test this hypothesis, we analysed the taxonomic and functional diversity of fungal isolates of symptomatic P. ramosa collected from infested tobacco-growing regions in France in order to identify one or more fungal strains for future biocontrol. The fungal isolates were characterized using morphological and molecular identification tools and tested for their ability to inhibit the germination of P. ramosa seeds, their necrotic activity on the stems of the pest and their non-pathogenicity to the host plant. We highlighted the specific richness of fungal colonizers associated with symptomatic P. ramosa. Among the 374 collected isolates, nearly 80% belonged to 19 Fusarium species. Eighty-seven isolates representative of this diversity also showed functional diversity by inhibiting seed germination of the parasite. The 20 best-performing isolates showed differences in germination inhibition of P. ramosa at the intraspecific level. Among these 20 fungal isolates, a set of 15 randomly selected isolates was tested for their necrotic activity on the parasite stems. Fusarium venenatum isolates showed dual competence, i.e. germination inhibition and necrotic activity, and were non-pathogenic to tobacco. This led us to discuss the potential mycoherbicidal effect of this fungal species on P. ramosa.
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Nicotiana , Orobanche , Endófitos/genética , Germinação/fisiologia , Orobanche/fisiologia , SementesRESUMO
Certain amino acids induce inhibitory effects in plant growth due to feedback inhibition of metabolic pathways. The inhibition patterns depend on plant species and the plant developmental stage. Those amino acids with inhibitory action on specific weeds could be utilized as herbicides, however, their use for weed control has not been put into practice. Orobanche minor is a weed that parasitizes red clover. O. minor germination is stimulated by clover root exudates. The subsequent seedling is an obligated parasite that must attach quickly to the clover root to withdraw its nutrients. Early development of O. minor is vulnerable to amino acid inhibition and therefore, a series of in vitro, rhizotron, and field experiments were conducted to investigate the potential of amino acids to inhibit O. minor parasitism. In in vitro experiments it was found that among a collection of 20 protein amino acids, lysine, methionine and tryptophan strongly interfere with O. minor early development. Field research confirmed their inhibitory effect but revealed that methionine was more effective than lysine and tryptophan, and that two successive methionine applications at 308 and 543 growing degree days inhibited O. minor emergence in red clover up to 67%. We investigated additional effects with potential to influence the practical use of amino acids against broomrape weeds, whether the herbicidal effect may be reversible by other amino acids exuded by host plants or may be amplified by inducing host resistance barriers against O. minor penetration. This paper suggests that amino acids may have the potential to be integrated into biorational programs of broomrape management.
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Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrapes are in current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of herbicide use and global warming to a lesser degree. We reviewed relevant facts about the biology and physiology of broomrape weeds and the major feasible control strategies. The points of vulnerability of some underground events, key for their parasitism such as crop-induced germination or haustorial development are reviewed as inhibition targets of the broomrape-crop association. Among the reviewed strategies are those aimed (1) to reduce broomrape seed bank viability, such as fumigation, herbigation, solarization and use of broomrape-specific pathogens; (2) diversion strategies to reduce the broomrape ability to timely detect the host such as those based on promotion of suicidal germination, on introduction of allelochemical interference, or on down-regulating host exudation of germination-inducing factors; (3) strategies to inhibit the capacity of the broomrape seedling to penetrate the crop and connect with the vascular system, such as biotic or abiotic inhibition of broomrape radicle growth and crop resistance to broomrape penetration either natural, genetically engineered or elicited by biotic- or abiotic-resistance-inducing agents; and (4) strategies acting once broomrape seedling has bridged its vascular system with that of the host, aimed to impede or to endure the parasitic sink such as those based on the delivery of herbicides via haustoria, use of resistant or tolerant varieties and implementation of cultural practices improving crop competitiveness.
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Phelipanche ramosa (L.) Pomel (branched broomrape) is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L.) (oilseed rape) and two weed species, Capsella bursa-pastoris (L.) Medik. and Geranium dissectum (L.). Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34 to 84%). B. napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per host plant, regardless of host growth rate. Results will be incorporated into a mechanistic model in order to analyze the effect of parasitic plant species on weed community assembly and to design new cropping systems for controlling P. ramosa.
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INTRODUCTION: Tuberculosis can be responsible for myocardial damage, the frequency of which is probably underestimated because of the difficulty in its diagnosis. We studied the contribution of cardiac magnetic resonance imaging (MRI) in three patients. OBSERVATIONS: Three patients were treated for disseminated tuberculosis. They had moderate cardiac abnormalities (tachycardia, dyspnoea on effort). The electrocardiogram was normal in 2 patients and the echocardiography showed localized hyperkinesias. Cardiac MRI revealed intra-myocardial nodular gadolinium enhancement and hyperkinesias. The clinical outcome in the 3 patients was favourable following anti-tuberculosis therapy; one patient was also administered corticosteroids. DISCUSSION: Cardiac MRI is a non-invasive examination that brought important arguments for the diagnosis of tubercular myocarditis in the 3 patients.
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Cardiomiopatias/diagnóstico , Imageamento por Ressonância Magnética , Tuberculose Cardiovascular/diagnóstico , Corticosteroides/uso terapêutico , Adulto , Antituberculosos/uso terapêutico , Sangue/microbiologia , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/tratamento farmacológico , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Resultado do Tratamento , Tuberculose Cardiovascular/diagnóstico por imagem , Tuberculose Cardiovascular/tratamento farmacológico , Urina/microbiologiaRESUMO
OBJECTIVE: Schizophrenia might appear to be an obstacle to the initiation of and especially compliance with antiretroviral therapy for HIV-infected patients. The aims of this study were to describe the clinical, immunologic and virologic course after initiation of antiretroviral therapy in 7 HIV patients with schizophrenia (according to DSM-IV-R criteria), and to analyse the possibilities of an adequate antiretroviral therapy for those patients. OBSERVATIONS: Multidisciplinary management by specialists in infectious diseases, addiction-related disorders, treatment adherence and compliance, and psychiatrists, as well as social workers, home care agencies, and patient advocacy and assistance groups, was organized with coordinated medical-psychiatric follow-up at least once a month. The patients, 6 men and 1 woman, were aged from 26 to 48 years; schizophrenia had been diagnosed in 5 patients 6 months to 20 years before the HIV infection was discovered; diagnoses of both diseases were essentially simultaneous for the other 2. All patients took long-term neuroleptics for their schizophrenia. Two were active drug addicts who received drug substitution treatment. Before antiretroviral treatment began, 6 patients had advanced infection: stage C with peak CD4 cell counts ranging from 6 to 70/mm3; they began treatment with protease inhibitors between May 1996 and August 1997. The seventh patient was first seen during primary HIV infection in July 1998, and treatment began then. Response to antiretroviral treatment with protease inhibitors was slow for all patients, but viral load became undetectable for 6 of the 7, after 5 months to 4 years; 3 had opportunistic infections. Follow-up ended in January 2002: 5 patients still had undetectable viral loads,, with CD4 cell counts ranging from 45 to 1 000/mm3. One patient died from mixed terminal cirrhosis (alcohol abuse and hepatitis C); the viral load in another was only partially controlled (10 000 copies/ml), because of poor treatment adherence. CONCLUSION: Individuals with schizophrenia can respond well to antiretroviral treatment, although response may appear slow; they can adhere to complex treatment regimens as long as they receive well coordinated and sustained multidisciplinary support.
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Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Cooperação do Paciente , Esquizofrenia/complicações , Esquizofrenia/virologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Transtornos Relacionados ao Uso de Substâncias , Resultado do Tratamento , Carga ViralRESUMO
In the Poitou-Charentes district, among the 82 species of winter rape weeds identified, 22 displayed a strong affinity for this crop (Brassica napus L.). In fields, 50% of these weeds were parasitized by Orobanche ramosa, playing the role of host plants. Greenhouse co-cultures (weed/Orobanche ramosa) showed that weeds non-parasitized in fields could be attacked by broomrape, developing a more or less complete cycle. In vitro co-cultures (weed/Orobanche ramosa) revealed that root exudates of non-parasitized weeds, in fields or in greenhouse co-cultures, could induce Orobanche ramosa seed germination, but not attachment. These weeds could play the role of false hosts.
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Brassica napus/fisiologia , Orobanche/fisiologia , França , Estações do AnoRESUMO
A psychotherapeutic approach for schizophrenia is now recommended as an adjuvant for psychopharmacology, since antipsychotic medications only have a partial impact especially as regards positive symptoms and insight. In addition, cognitive distortions and the lack of metacognitive skills might increase positive symptoms leading to poor social functioning. This underlines the need for specific approaches which target cognitive processes relevant for insight, and abilities in metacognition. Metacognitive training (MCT) is a structured group intervention, which enhances a patient's reflection on cognitive biases and improves problem-solving. The aim of our study was to assess MCTs' short term impact on insight, symptoms and quality of life. Fifty patients with schizophrenia or schizoaffective disorders and persistent positive symptoms (delusions or hallucinations) were enrolled in the study. After baseline assessment participants were randomised either to supportive therapy or MCT. Both groups used the same design (1h-session twice a week during 8weeks) although the basic knowledge given to participants was different between interventions. Participants were assessed at eight weeks based on the Scale to Assess Unawareness of Mental Disorder, Positive and Negative Syndrome Scale (PANSS), Psychotic Symptom Rating Scales, the Calgary Depression Scale for Schizophrenia and the Quality of Life Scale. Between-group differences were significant in favour of MCT on the PANSS positive scale. Between-group differences in post- and pre-test values showed a trend in favour of MCT for insight on hallucinations. Results of our study indicate that the MCT has an effect on reducing positive symptomatology, and a trend impact on insight and social functioning.
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Terapia Cognitivo-Comportamental/métodos , Transtornos Psicóticos/terapia , Esquizofrenia/terapia , Adulto , Delusões/fisiopatologia , Delusões/terapia , Feminino , França , Alucinações/fisiopatologia , Alucinações/terapia , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/fisiopatologia , Qualidade de Vida , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Ajustamento Social , Pensamento , Fatores de Tempo , Resultado do TratamentoRESUMO
We report on the underlying molecular mechanisms likely responsible for the high-level fluconazole resistance in a Candida lusitaniae clinical isolate. Fluconazole resistance correlated with overexpression of ERG11 and of several efflux pump genes, in particular, the orthologs of the Candida albicans MDR1, PDR16, CDR1, CDR2, and YOR1.
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Candida/efeitos dos fármacos , Candida/genética , Farmacorresistência Fúngica/genética , Fluconazol/farmacologia , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/genética , Sistema Enzimático do Citocromo P-450/genética , Primers do DNA , Proteínas Fúngicas/genética , Humanos , Proteínas de Membrana Transportadoras/genética , Metiltransferases/genética , Oxirredutases/genética , Reação em Cadeia da Polimerase/métodosRESUMO
Freshly harvested barley seeds are considered as dormant since they do not germinate at temperatures above 20 degrees C. This dormancy is broken during dry storage. Molecular regulation of dormancy was investigated using cDNA-AFLP to identify transcripts differentially expressed in dormant and non-dormant embryos. Transcript patterns in embryos from dry dormant and non-dormant seeds and from both seeds imbibed for 5 h at 30 degrees C, a temperature at which dormancy is expressed, were compared. Thirty-nine Transcript-Derived Fragments (TDF) that were reproducibly differentially expressed among treatments were identified, and 25 of these were cloned and sequenced. Among these, eight transcripts were observed to be differentially expressed during after-ripening, seven of which decline, probably due to post-maturation degradation. HV13B, TDF identified as having homology to fructose-6-phosphate-2-kinase/fructose-2,6-biphosphatase, may have a role in the maintenance of dormancy in barley and probably in other cereals. During the first 5 h of imbibition, there was expression of 24 TDF which was apparently independent of dormancy, revealing putative epigenetic regulation. This was typified by HV44A, a SET domain protein. Seven TDF differentially expressed, and especially HV12D, HV42B, and HV32B, in dormant and non-dormant seeds were potential signalling elements. HV12D had homology with an ARIADNE gene which could be implicated in ABA signalling.
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Germinação , Hordeum/embriologia , Proteínas de Plantas/fisiologia , Polimorfismo Genético , RNA Mensageiro/metabolismo , Sementes/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Hordeum/genética , Hordeum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismoRESUMO
Inactivation of the FCY2 (cytosine permease), FCY1 (cytosine deaminase), and FUR1 (uracil phosphoribosyltransferase) genes in Candida lusitaniae produced two patterns of resistance to flucytosine. Mutant fur1 demonstrated resistance to 5-fluorouracil, whereas mutants fcy1 and fcy2 demonstrated fluconazole resistance in the presence of subinhibitory flucytosine concentrations.
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Candida/efeitos dos fármacos , Farmacorresistência Fúngica/genética , Fluconazol/farmacologia , Flucitosina/farmacologia , Fluoruracila/farmacologia , Alelos , Antifúngicos/farmacologia , Candida/enzimologia , Candida/genética , Clonagem Molecular , Citosina Desaminase/genética , DNA Fúngico/química , DNA Fúngico/genética , Proteínas Fúngicas/genética , Teste de Complementação Genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Mutação , Pentosiltransferases/genética , Plasmídeos/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Plexiform fibrohistiocytic tumor is a soft-tissue tumor of intermediate malignancy occurring in children and young adults but is only rarely found in infants. The tumor usually involves the upper limbs and is slow growing and painless. Recurrence rate is high. Lymph node and systemic metastases can occur, but have never been reported in infants. Clinical behavior in infancy is not known. Histologically, the tumor is characterized by nodules of histiocyte-like and multinucleated cells and fascicles of spindle cells arranged in a plexiform pattern. Mitosis, atypia, and nuclear pleomorphism are common but not pronounced. METHODS AND RESULTS: We report three cases in infants, one of which is congenital, having an unusual topography and a broad histological spectrum. CONCLUSION: In infants, wide excision with large safety margins should be performed as the behaviour of this tumor remains uncertain. Leclerc S, Hamel-Teillac D, Oger P, Brousse N, Fraitag S. Plexiform fibrohistiocytic tumor: three unusual cases occurring in infancy.