502 research outputs found

    Iatrogenic Cushing’s syndrome and Secondary Adrenal Insufficiency in an HIV Patientreceiving Fluticasone and Ritonavir

    Get PDF
    Objectives: To illustrate that the protease inhibitor (PI) ritonavir, widely used as part of the treatment for HIV, might cause drug–drug interactions with inhaled corticosteroids. Material and methods: A case report is presented. Results: An HIV-positive patient presented with gradually changing body composition that was ascribed to lipodystrophy. Finally, iatrogenic Cushing's syndrome with secondary adrenal insufficiency was diagnosed due to a drug–drug interaction of ritonavir and fluticasone. Conclusion: Lipodystrophy might mimic Cushing's syndrome. The combination of ritonavir and inhaled fluticasone may lead to systemic steroid excess causing Cushing's syndrome and secondary adrenal insufficiency

    A self-interaction corrected pseudopotential scheme for magnetic and strongly-correlated systems

    Full text link
    Local-spin-density functional calculations may be affected by severe errors when applied to the study of magnetic and strongly-correlated materials. Some of these faults can be traced back to the presence of the spurious self-interaction in the density functional. Since the application of a fully self-consistent self-interaction correction is highly demanding even for moderately large systems, we pursue a strategy of approximating the self-interaction corrected potential with a non-local, pseudopotential-like projector, first generated within the isolated atom and then updated during the self-consistent cycle in the crystal. This scheme, whose implementation is totally uncomplicated and particularly suited for the pseudopotental formalism, dramatically improves the LSDA results for a variety of compounds with a minimal increase of computing cost.Comment: 18 pages, 14 figure

    Strong-correlation effects in Born effective charges

    Full text link
    Large values of Born effective charges are generally considered as reliable indicators of the genuine tendency of an insulator towards ferroelectric instability. However, these quantities can be very much influenced by strong electron correlation and metallic behavior, which are not exclusive properties of ferroelectric materials. In this paper we compare the Born effective charges of some prototypical ferroelectrics with those of magnetic, non-ferroelectric compounds using a novel, self-interaction free methodology that improves on the local-density approximation description of the electronic properties. We show that the inclusion of strong-correlation effects systermatically reduces the size of the Born effective charges and the electron localization lengths. Furthermore we give an interpretation of the Born effective charges in terms of band energy structure and orbital occupations which can be used as a guideline to rationalize their values in the general case.Comment: 10 pages, 4 postscript figure

    Effects of methimazole on the elimination of irinotecan

    Get PDF
    Purpose: To study the possible pharmacokinetic and pharmacodynamic interactions between irinotecan and methimazole. Methods: A patient treated for colorectal cancer with single agent irinotecan received methimazole co-medication for Graves' disease. Irinotecan pharmacokinetics and side effects were followed during a total of four courses (two courses with and two courses without methimazole). Results: Plasma concentrations of the active irinotecan metabolite SN-38 and its inactive metabolite SN-38-Glucuronide were both higher (a mean increase of 14 and 67%, respectively) with methimazole co-medication, compared to irinotecan monotherapy. As a result, the mean SN-38 glucuronidation rate increased with 47% during concurrent treatment. Other possible confounding factors did not change over time. Specific adverse events due to methimazole co-treatment were not seen. Conclusions: Additional in vitro experiments suggest that these results can be explained by induction of UGT1A1 by methimazole, leading to higher SN-38G concentrations. The prescribed combination of these drugs may lead to highly toxic intestinal SN-38 levels. We therefore advise physicians to be very careful in combining methimazole with regular irinotecan doses, especially in patients who are prone to irinotecan toxicity

    Report on short-term side effects of treatments with 177Lu- octreotate in combination with capecitabine in seven patients with gastroenteropancreatic neuroendocrine tumours

    Get PDF
    Purpose: Treatment with the radiolabelled somatostatin analogue177Lu-octreotate results in tumour remission in 47% of patients with gastroenteropancreatic neuroendocrine tumours. Adding capecitabine to177Lu-octreotate, as a radio-sensitiser, may enhance these anti-tumour effects. We now present the short-term toxicity profile of this novel combination. Methods: Seven patients were treated with 7.4 GBq177Lu-octreotate and capecitabine (1650 mg/m2per day) for 2 weeks with an intended number of four cycles. Toxicity, and especially haematological and renal parameters, were monitored on a weekly basis for the first two cycles and 4 and 6 weeks after subsequent cycles. Results: None of the patients had hand-foot syndrome. One patient had grade 1 stomatitis occurring after one of four cycles. Grade 3 or 4 leukopenia or neutropenia did not occur. One patient had grade 3 anaemia, but none had grade 4 anaemia. One patient had grade 2 thrombocytopenia after the fourth cycle, and one had grade 3 thrombocytopenia. Grade 4 thrombocytopenia did not occur. No significant changes in serum creatinine levels were observed. None of the patients had symptoms of cardiac ischaemia. Conclusions: Treatment with the combination of177Lu-octreotate and capecitabine was feasible and safe considering acute and subacute side effects. We therefore started a randomised, controlled clinical trial to compare this combination with177Lu-octreotate as single agent with regard to anti-tumour effects and side effects

    A Mitochondrial calcium dynamics - checks and balances of energy physiology

    Get PDF
    Mitochondria conserve the energy released from metabolic redox reactions and supply the cell with ATP. When the rate of respiratory metabolism does not match ATP demand active regulation of mitochondrial function is essential. For plants particularly sophisticated regulation strategies can be expected, to ensure maintenance of homeostasis in the presence of frequent environmental changes. Yet, the mechanisms by which such control is achieved in vivo are poorly understood. Calcium acts as a key regulator of mitochondrial energy metabolism in mammals by modulating the activity TCA cycle dehydrogenases. Calcium flux into the matrix is controlled by the recently identified mitochondrial uniporter complex. Plants contain homologues of components of the uniporter, but their function has been unclear. To understand how mitochondrial calcium dynamics are regulated and what their impact is on energy metabolism, we have combined reverse genetics with in vivo sensing of calcium. Fluorescent protein sensors and quantitative confocal imaging allow monitoring of mitochondrial energy physiology in living Arabidopsis tissues. We have found that several homologues of components of the mitochondrial calcium uniporter complex localize to mitochondria in Arabidopsis. Mutant lines have shown severely altered mitochondrial calcium levels and abnormal organellar calcium transients, providing a novel genetic handle on the dissection of the role of calcium regulation in plant mitochondria. We will discuss the specific impact of de-regulated mitochondrial calcium on the physiological network and the function of plant mitochondria

    Silver nanowires with optimized silica coating as versatile plasmonic resonators

    Get PDF
    Metal nanoparticles are the most frequently used nanostructures in plasmonics. However, besides nanoparticles, metal nanowires feature several advantages for applications. Their elongation offers a larger interaction volume, their resonances can reach higher quality factors, and their mode structure provides better coupling into integrated hybrid dielectric plasmonic circuits. It is crucial though, to control the distance of the wire to a supporting substrate, to another metal layer or to active materials with sub nanometer precision. A dielectric coating can be utilized for distance control, but it must not degrade the plasmonic properties. In this paper, we introduce a controlled synthesis and coating approach for silver nanowires to fulfill these demands. We synthesize and characterize silver nanowires of around 70 amp; 8201;nm in diameter. These nanowires are coated with nm sized silica shells using a modified Stöber method to achieve a homogeneous and smooth surface quality. We use transmission electron microscopy, dark field microscopy and electron energy loss spectroscopy to study morphology and plasmonic resonances of individual nanowires and quantify the influence of the silica coating. Thorough numerical simulations support the experimental findings showing that the coating does not deteriorate the plasmonic properties and thus introduce silver nanowires as usable building blocks for integrated hybrid plasmonic system

    Emergent and robust ferromagnetic-insulating state in highly strained ferroelastic LaCoO3 thin films

    Get PDF
    Transition metal oxides are promising candidates for the next generation of spintronic devices due to their fascinating properties that can be effectively engineered by strain, defects, and microstructure. An excellent example can be found in ferroelastic LaCoO3 with paramagnetism in bulk. In contrast, unexpected ferromagnetism is observed in tensile-strained LaCoO3 films, however, its origin remains controversial. Here we simultaneously reveal the formation of ordered oxygen vacancies and previously unreported long-range suppression of CoO6 octahedral rotations throughout LaCoO3 films. Supported by density functional theory calculations, we find that the strong modification of Co 3d-O 2p hybridization associated with the increase of both Co-O-Co bond angle and Co-O bond length weakens the crystal-field splitting and facilitates an ordered high-spin state of Co ions, inducing an emergent ferromagnetic-insulating state. Our work provides unique insights into underlying mechanisms driving the ferromagnetic-insulating state in tensile-strained ferroelastic LaCoO3 films while suggesting potential applications toward low-power spintronic devices
    • …
    corecore