220 research outputs found
Is there a need to review the syndromic case management of vaginal discharge due to candida in the Indian scenario?
Background: Vulvovaginal candidiasis (VVC) affects approximately 75% of women once in lifetime. National AIDS Control Organization has recommended Kit-2/Green (tablet secnidazole 2 gm OD stat and capsule fluconazole 150 mg OD stat) for syndromic case management (SCM) of patients with vaginal discharge since 2007. Patients are frequently revisiting the STI centre with recurrent VVC. The purpose of the study was to determine the effectiveness of fluconazole and other azoles in vulvovaginitis.
Methods: Vaginal swabs from 188 patients attending regional STI centre, at Government Medical College, Nagpur between October 2020 to June 2022 were processed. A total of 128 conventionally confirmed isolates of Candida species were tested on RPMI 1640 medium for susceptibility to azoles by E test. An MIC of ≥8 μg/ml for fluconazole and ≥1 μg/ml for itraconazole, ketoconazole and voriconazole was interpreted as resistance as per CLSI M-60.
Results: Candida species isolated were Candida albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. dubliniensis and C. krusei. Candida species resistant to fluconazole, itraconazole, ketoconazole and voriconazole were 22 (17.18%), 53 (41.40%), 19 (14.84%), and 3 (2.34%) respectively. C. glabrata was most resistant while C. parapsilosis was least resistant. Voriconazole was most effective.
Conclusions: Extensive use of fluconazole in syndromic case management of vaginal discharge could be the probable reason for 17.18% resistance to fluconazole. Withdrawal of fluconazole and replacement with another antifungal azole in SCM of vaginal discharge may prevent recurrent VVC and perhaps lead to emergence of fluconazole sensitive candida
Altered Backbone and Side-Chain Interactions Result in Route Heterogeneity during the Folding of Interleukin-1b (IL-1b)
Deletion of the b-bulge trigger-loop results in both a switch in the preferred folding route, from the functional loop
packing folding route to barrel closure, as well as conversion of the agonist activity of IL-1b into antagonist activity. Conversely,
circular permutations of IL-1b conserve the functional folding route as well as the agonist activity. These two extremes in the
folding-functional interplay beg the question of whether mutations in IL-1b would result in changes in the populations of heterogeneous
folding routes and the signaling activity. A series of topologically equivalent water-mediated b-strand bridging interactions
within the pseudosymmetric b-trefoil fold of IL-1b highlight the backbone water interactions that stabilize the secondary and
tertiary structure of the protein. Additionally, conserved aromatic residues lining the central cavity appear to be essential for both
stability and folding. Here, we probe these protein backbone-water molecule and side chain-side chain interactions and the role
they play in the folding mechanism of this geometrically stressed molecule. We used folding simulations with structure-based
models, as well as a series of folding kinetic experiments to examine the effects of the F42W core mutation on the folding landscape
of IL-1b. This mutation alters water-mediated backbone interactions essential for maintaining the trefoil fold. Our results
clearly indicate that this perturbation in the primary structure alters a structural water interaction and consequently modulates the
population of folding routes accessed during folding and signaling activity
Folding Circular Permutants of IL-1β: Route Selection Driven by Functional Frustration
Interleukin-1β (IL-1β) is the cytokine crucial to inflammatory and immune response. Two dominant routes are populated in the folding to native structure. These distinct routes are a result of the competition between early packing of the functional loops versus closure of the β-barrel to achieve efficient folding and have been observed both experimentally and computationally. Kinetic experiments on the WT protein established that the dominant route is characterized by early packing of geometrically frustrated functional loops. However, deletion of one of the functional loops, the β-bulge, switches the dominant route to an alternative, yet, as accessible, route, where the termini necessary for barrel closure form first. Here, we explore the effect of circular permutation of the WT sequence on the observed folding landscape with a combination of kinetic and thermodynamic experiments. Our experiments show that while the rate of formation of permutant protein is always slower than that observed for the WT sequence, the region of initial nucleation for all permutants is similar to that observed for the WT protein and occurs within a similar timescale. That is, even permutants with significant sequence rearrangement in which the functional-nucleus is placed at opposing ends of the polypeptide chain, fold by the dominant WT “functional loop-packing route”, despite the entropic cost of having to fold the N- and C- termini early. Taken together, our results indicate that the early packing of the functional loops dominates the folding landscape in active proteins, and, despite the entropic penalty of coalescing the termini early, these proteins will populate an entropically unfavorable route in order to conserve function. More generally, circular permutation can elucidate the influence of local energetic stabilization of functional regions within a protein, where topological complexity creates a mismatch between energetics and topology in active proteins
Plakophilin3 Loss Leads to an Increase in PRL3 Levels Promoting K8 Dephosphorylation, Which Is Required for Transformation and Metastasis
The desmosome anchors keratin filaments in epithelial cells leading to the formation of a tissue wide IF network. Loss of the desmosomal plaque protein plakophilin3 (PKP3) in HCT116 cells, leads to an increase in neoplastic progression and metastasis, which was accompanied by an increase in K8 levels. The increase in levels was due to an increase in the protein levels of the Phosphatase of Regenerating Liver 3 (PRL3), which results in a decrease in phosphorylation on K8. The increase in PRL3 and K8 protein levels could be reversed by introduction of an shRNA resistant PKP3 cDNA. Inhibition of K8 expression in the PKP3 knockdown clone S10, led to a decrease in cell migration and lamellipodia formation. Further, the K8 PKP3 double knockdown clones showed a decrease in colony formation in soft agar and decreased tumorigenesis and metastasis in nude mice. These results suggest that a stabilisation of K8 filaments leading to an increase in migration and transformation may be one mechanism by which PKP3 loss leads to tumor progression and metastasis
Bias-induced conductance switching in single molecule junctions containing a redox-active transition metal complex
An approach to locating delayed activities in software processes
Activity is now playing a vital role in software processes. To ensure the high-level efficiency of software processes, a key point is to locate those activities that own bigger resource occupation probabilities with respect to average execution time, called delayed activities, and then improve them. To this end, we firstly propose an approach to locating delayed activities in software processes. Furthermore, we present a case study, which exhibits the high-level efficiency of the approach, to concretely illustrate this new solution. Some beneficial analysis and reasonable modification are developed in the end
Approximate policy iteration: A survey and some new methods
We consider the classical policy iteration method of dynamic programming (DP), where approximations and simulation are used to deal with the curse of dimensionality. We survey a number of issues: convergence and rate of convergence of approximate policy evaluation methods, singularity and susceptibility to simulation noise of policy evaluation, exploration issues, constrained and enhanced policy iteration, policy oscillation and chattering, and optimistic and distributed policy iteration. Our discussion of policy evaluation is couched in general terms and aims to unify the available methods in the light of recent research developments and to compare the two main policy evaluation approaches: projected equations and temporal differences (TD), and aggregation. In the context of these approaches, we survey two different types of simulation-based algorithms: matrix inversion methods, such as least-squares temporal difference (LSTD), and iterative methods, such as least-squares policy evaluation (LSPE) and TD (λ), and their scaled variants. We discuss a recent method, based on regression and regularization, which rectifies the unreliability of LSTD for nearly singular projected Bellman equations. An iterative version of this method belongs to the LSPE class of methods and provides the connecting link between LSTD and LSPE. Our discussion of policy improvement focuses on the role of policy oscillation and its effect on performance guarantees. We illustrate that policy evaluation when done by the projected equation/TD approach may lead to policy oscillation, but when done by aggregation it does not. This implies better error bounds and more regular performance for aggregation, at the expense of some loss of generality in cost function representation capability. Hard aggregation provides the connecting link between projected equation/TD-based and aggregation-based policy evaluation, and is characterized by favorable error bounds.National Science Foundation (U.S.) (No.ECCS-0801549)Los Alamos National Laboratory. Information Science and Technology InstituteUnited States. Air Force (No.FA9550-10-1-0412
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