871 resultados para Antifungal agent


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Case Number 91-151 Craig Gardner, an inmate in the Iowa prison system, was the subject of a force move by correctional officers while incarcerated at the Iowa State Penitentiary (ISP). This action involved the use of a chemical agent. This investigation began as a review of the use of a chemical agent in a forced cell move on June 30, 1991.

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A variety of stress situations may affect the activity and survival of plant-beneficial pseudomonads added to soil to control root diseases. This study focused on the roles of the sigma factor AlgU (synonyms, AlgT, RpoE, and sigma(22)) and the anti-sigma factor MucA in stress adaptation of the biocontrol agent Pseudomonas fluorescens CHA0. The algU-mucA-mucB gene cluster of strain CHA0 was similar to that of the pathogens Pseudomonas aeruginosa and Pseudomonas syringae. Strain CHA0 is naturally nonmucoid, whereas a mucA deletion mutant or algU-overexpressing strains were highly mucoid due to exopolysaccharide overproduction. Mucoidy strictly depended on the global regulator GacA. An algU deletion mutant was significantly more sensitive to osmotic stress than the wild-type CHA0 strain and the mucA mutant were. Expression of an algU'-'lacZ reporter fusion was induced severalfold in the wild type and in the mucA mutant upon exposure to osmotic stress, whereas a lower, noninducible level of expression was observed in the algU mutant. Overexpression of algU did not enhance tolerance towards osmotic stress. AlgU was found to be essential for tolerance of P. fluorescens towards desiccation stress in a sterile vermiculite-sand mixture and in a natural sandy loam soil. The size of the population of the algU mutant declined much more rapidly than the size of the wild-type population at soil water contents below 5%. In contrast to its role in pathogenic pseudomonads, AlgU did not contribute to tolerance of P. fluorescens towards oxidative and heat stress. In conclusion, AlgU is a crucial determinant in the adaptation of P. fluorescens to dry conditions and hyperosmolarity, two major stress factors that limit bacterial survival in the environment.

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Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies.

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Parachlamydia acanthamoebae is a Chlamydia-like organism that easily grows within Acanthamoeba spp. Thus, it probably uses these widespread free-living amoebae as a replicative niche, a cosmopolite aquatic reservoir and a vector. A potential role of P. acanthamoebae as an agent of lower respiratory tract infection was initially suggested by its isolation within an Acanthamoeba sp. recovered from the water of a humidifier during the investigation of an outbreak of fever. Additional serological and molecular-based investigations further supported its pathogenic role, mainly in bronchiolitis, bronchitis, aspiration pneumonia and community-acquired pneumonia. P. acanthamoebae was shown to survive and replicate within human macrophages, lung fibroblasts and pneumocytes. Moreover, this strict intracellular bacterium also causes severe pneumonia in experimentally infected mice, thus fulfilling the third and fourth Koch criteria for a pathogenic role. Consequently, new tools have been developed for the diagnosis of parachlamydial infections. It will be important to routinely search for this emerging agent of pneumonia, as P. acanthamoebae is apparently resistant to quinolones, which are antibiotics often used for the empirical treatment of atypical pneumonia. Other Chlamydia-related bacteria, including Protochlamydia naegleriophila, Simkania negevensis and Waddlia chondrophila, might also cause lung infections. Moreover, several additional novel chlamydiae, e.g. Criblamydia sequanensis and Rhabdochlamydia crassificans, have been discovered and are now being investigated for their human pathogenicity.

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Introduction: Mantle cell lymphoma (MCL) accounts for 6% of all B-cell lymphomas and remains incurable for most patients. Those who relapse after first line therapy or hematopoietic stem cell transplantation have a dismal prognosis with short response duration after salvage therapy. On a molecular level, MCL is characterised by the translocation t[11;14] leading to Cyclin D1 overexpression. Cyclin D1 is downstream of the mammalian target of rapamycin (mTOR) kinase and can be effectively blocked by mTOR inhibitors such as temsirolimus. We set out to define the single agent activity of the orally available mTOR inhibitor everolimus (RAD001) in a prospective, multi-centre trial in patients with relapsed or refractory MCL (NCT00516412). The study was performed in collaboration with the EU-MCL network. Methods: Eligible patients with histologically/cytologically confirmed relapsed (not more than 3 prior lines of systemic treatment) or refractory MCL received everolimus 10 mg orally daily on day 1 - 28 of each cycle (4 weeks) for 6 cycles or until disease progression. The primary endpoint was the best objective response with adverse reactions, time to progression (TTP), time to treatment failure, response duration and molecular response as secondary endpoints. A response rate of ≤ 10% was considered uninteresting and, conversely, promising if ≥ 30%. The required sample size was 35 pts using the Simon's optimal two-stage design with 90% power and 5% significance. Results: A total of 36 patients with 35 evaluable patients from 19 centers were enrolled between August 2007 and January 2010. The median age was 69.4 years (range 40.1 to 84.9 years), with 22 males and 13 females. Thirty patients presented with relapsed and 5 with refractory MCL with a median of two prior therapies. Treatment was generally well tolerated with anemia (11%), thrombocytopenia (11%), neutropenia (8%), diarrhea (3%) and fatigue (3%) being the most frequent complications of CTC grade III or higher. Eighteen patients received 6 or more cycles of everolimus treatment. The objective response rate was 20% (95% CI: 8-37%) with 2 CR, 5 PR, 17 SD, and 11 PD. At a median follow-up of 6 months, TTP was 5.45 months (95% CI: 2.8-8.2 months) for the entire population and 10.6 months for the 18 patients receiving 6 or more cycles of treatment. Conclusion: This study demonstrates that single agent everolimus 10 mg once daily orally is well tolerated. The null hypothesis of inactivity could be rejected indicating a moderate anti-lymphoma activity in relapsed/refractory MCL. Further studies of either everolimus in combination with chemotherapy or as single agent for maintenance treatment are warranted in MCL.

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The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241 Candida albicans transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (RCA1), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from RCA1 deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a C. albicans transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.

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I study the optimal project choice when the principal relies on the agent in charge of production for project evaluation. The principal has to choose between a safe project generating a fixed revenue and a risky project generating an uncertain revenue. The agent has private information about the production cost under each project but also about the signal regarding the profitability of the risky project. If the signal favoring the adoption of the risky project is goods news to the agent, integrating production and project evaluation tasks does not generate any loss compared to the benchmark in which the principal herself receives the signal. By contrast, if it is bad news, task integration creates an endogenous reservation utility which is type-dependent and thereby generates countervailing incentives, which can make a bias toward either project optimal. Our results can offer an explanation for why good firms can go bad and a rationale for the separation of day-to-day operating decisions from long-term strategic decisions stressed by Williamson.

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Invasive fungal infections are an increasingly frequent etiology of sepsis in critically ill patients causing substantial morbidity and mortality. Candida species are by far the predominant agent of fungal sepsis accounting for 10% to 15% of health-care associated infections, about 5% of all cases of severe sepsis and septic shock and are the fourth most common bloodstream isolates in the United States. One-third of all episodes of candidemia occur in the intensive care setting. Early diagnosis of invasive candidiasis is critical in order to initiate antifungal agents promptly. Delay in the administration of appropriate therapy increases mortality. Unfortunately, risk factors, clinical and radiological manifestations are quite unspecific and conventional culture methods are suboptimal. Non-culture based methods (such as mannan, anti-mannan, β-d-glucan, and polymerase chain reaction) have emerged but remain investigational or require additional testing in the ICU setting. Few prophylactic or pre-emptive studies have been performed in critically ill patients. They tended to be underpowered and their clinical usefulness remains to be established under most circumstances. The antifungal armamentarium has expanded considerably with the advent of lipid formulations of amphotericin B, the newest triazoles and the echinocandins. Clinical trials have shown that the triazoles and echinocandins are efficacious and well tolerated antifungal therapies. Clinical practice guidelines for the management of invasive candidiasis have been published by the European Society for Clinical Microbiology and Infectious Diseases and the Infectious Diseases Society of North America.

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Agent-based computational economics is becoming widely used in practice. This paperexplores the consistency of some of its standard techniques. We focus in particular on prevailingwholesale electricity trading simulation methods. We include different supply and demandrepresentations and propose the Experience-Weighted Attractions method to include severalbehavioural algorithms. We compare the results across assumptions and to economic theorypredictions. The match is good under best-response and reinforcement learning but not underfictitious play. The simulations perform well under flat and upward-slopping supply bidding,and also for plausible demand elasticity assumptions. Learning is influenced by the number ofbids per plant and the initial conditions. The overall conclusion is that agent-based simulationassumptions are far from innocuous. We link their performance to underlying features, andidentify those that are better suited to model wholesale electricity markets.

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The paper proposes a numerical solution method for general equilibrium models with a continuum of heterogeneous agents, which combines elements of projection and of perturbation methods. The basic idea is to solve first for the stationary solutionof the model, without aggregate shocks but with fully specified idiosyncratic shocks. Afterwards one computes a first-order perturbation of the solution in the aggregate shocks. This approach allows to include a high-dimensional representation of the cross-sectional distribution in the state vector. The method is applied to a model of household saving with uninsurable income risk and liquidity constraints. The model includes not only productivity shocks, but also shocks to redistributive taxation, which cause substantial short-run variation in the cross-sectional distribution of wealth. If those shocks are operative, it is shown that a solution method based on very few statistics of the distribution is not suitable, while the proposed method can solve the model with high accuracy, at least for the case of small aggregate shocks. Techniques are discussed to reduce the dimension of the state space such that higher order perturbations are feasible.Matlab programs to solve the model can be downloaded.

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Background a nd A ims: I nfliximab (IFX), adalimumab (ADA)and certolizumab pegol (CZP) have similar efficacy for inductionand maintenance of clinical response and remission in Crohn'sdisease (CD). Given the comparable nature of t hese drugs,patients' p references m ay i nfluence the choice o f the product.Goal: to identify factors contributing to CD patients' decision inselecting one anti-TNF agent over the others.Methods: A p rospectdive s urvey was performed a mong a nti-TNF-naïve CD patients. Prior to completion of a questionnaire,patients were provided with a description of the three anti-TNFagents f ocusing on indications, route of administration, s ideeffects, and scientific evidence of efficacy and safety.Results: One hundred patients (47f/53m, mean age 45±16yrs)completed the questionnaire. Disease location was ileal, colonicand ileocolonic in 33%, 40% and 27% of patients, respectively.Thirty-six percent preferred ADA as medication of choice, while28% and 2 5% p referred CZP and IFX; 11% were u ndecided.Patients' decision in selecting an anti-TNF drug was influencedby t he following f actors: side effects ( 76%), p hysician'srecommendation (66%), route of administration (54%), efficacydata (52%), time required for therapy administration (27%),recommendations by other CD patients (21%) and interactionswith other medications (12%).Conclusions: T he majority of p atients p referred anti-TNFmedications t hat were a dministered by s ubcutaneous i njectionrather t han b y intravenous i nfusion. Side effect profile andphysicians' r ecommendation are t wo m ajor factors influencingthe patients' s election of a specific anti-TNF d rug. Patients'concerns about safety and lifestyle habits should be taken intoaccount when prescribing anti-TNF drugs.

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Introduction: Mantle cell lymphoma (MCL) accounts for 6% of all B-cell lymphomas and is in most cases an incurable disease. It is characterized by the translocation t(11;14) leading to Cyclin D1 over-expression. Cyclin D1 is downstream of the mammalian target of rapamycin (mTOR) threonine kinase and can be effectively blocked by mTOR inhibitors. We set out to define the single agent activity of the orally available mTOR inhibitor everolimus in a prospective, multicentre trial in patients with relapsed or refractory MCL (NCT00516412).Methods: Eligible patients with confirmed relapsed or refractory MCL received everolimus 10 mg for 28 days (one cycle) for a total of 6 cycles or until disease progression. The primary endpoint was the best objective response (OR) with adverse reactions, time to progression (TTP), time to treatment failure, response duration and molecular response as secondary endpoints.Results: A total of 36 patients with 35 evaluable patients at a median age of 69 years (range 40 to 85 years) from 19 centers were enrolled between August 2007 and January 2010. Treatment was generally well tolerated with anemia (11%), thrombocytopenia (11%), neutropenia (8%), diarrhea (3%) and fatigue (3%) being the most frequent complications of CTC grade 3 or higher. The OR rate was 20% (95% CI: 8-37%) with 2 complete remissions (CR) and 5 partial response (PR), stable disease (SD) 48% and progression disease (PD) 28%. At a median follow-up of 6 months, TTP was 5.45 months (95% CI: 2.8-8.2 months) for the entire population and 10.6 months for the 18 patients receiving 6 or more cycles of treatment. Three patients achieved a lasting complete molecular response when assessed in the peripheral blood.Conclusion: This study demonstrates that single agent everolimus is well tolerated and has anti-lymphoma activity including lasting molecular responses. Further studies of everolimus either in combination with chemotherapy or as single agent for maintenance treatment are warranted in MCL.