490 research outputs found
On the hydrolysis of the Dysprosium(III) ion
The hydrolysis of the Dysprosium (III) (Dy 3+ ) ion has been investigated at 25°C in 1, 2 and 3 molal (Na)ClO4 medium through a combined potentiometricâcoulometric methodology. At each perchlorate concentration the formation constants of the complexes DyOH 2+ , Dy2(OH)2 4+ and Dy5(OH)9 6+ have been determined. The values have then been extrapolated to zero ionic strength by using the Specific Interaction Theory. Analogies with the hydrolysis mechanism of other lanthanides are pointed out. This paper is just the first to be reported of a series of studies undertaken with the aim to prove that a single mechanism of hydrolysis applies to all the trivalent lanthanides and probably to the corresponding actinides, too radioactive to be investigated directly
Preparation of pyrimidin-2-one derivatives via base-mediated decomposition of uracil-analogues Fischer carbene complex
A practical and efficient synthesis of pyrimidin-2-one derivatives from Fischer carbene complex uracil-analogues through base-mediated elimination reactions is described. The scope of the protocol has been explored with the preparation of a variety of pyrimidin-2-one derivatives by base mediated demetallation of N-1 and N-3 substituted uracil Fischer carbene
Bench-to-bedside review: preventive measures for contrast-induced nephropathy in critically ill patients
An increasing number of diagnostic imaging procedures requires the use of intravenous radiographic contrast agents, which has led to a parallel increase in the incidence of contrast-induced nephropathy. Risk factors for development of contrast-induced nephropathy include pre-existing renal dysfunction (especially diabetic nephropathy and multiple myeloma-associated nephropathy), dehydration, congestive heart failure and use of concurrent nephrotoxic medication (including aminoglycosides and amphotericin B). Because contrast-induced nephropathy accounts for a significant increase in hospital-acquired renal failure, several strategies to prevent contrast-induced nephropathy are currently advocated, including use of alternative imaging techniques (for which contrast media are not needed), use of (the lowest possible amount of) iso-osmolar or low-osmolar contrast agents (instead of high-osmolar contrast agents), hyperhydration and forced diuresis. Administration of N-acetylcysteine, theophylline, or fenoldopam, sodium bicarbonate infusion, and periprocedural haemofiltration/haemodialysis have been investigated as preventive measures in recent years. This review addresses the literature on these newer strategies. Since only one (nonrandomized) study has been performed in intensive care unit patients, at present it is difficult to draw firm conclusions about preventive measures for contrast-induced nephropathy in the critically ill. Further studies are needed to determine the true role of these preventive measures in this group of patients who are at risk for contrast-induced nephropathy. Based on the available evidence, we advise administration of N-acetylcysteine, preferentially orally, or theophylline intravenously, next to hydration with bicarbonate solutions
The laminA/NF-Y protein complex reveals an unknown transcriptional mechanism on cell proliferation
Lamin A is a component of the nuclear matrix that also controls proliferation by
largely unknown mechanisms. NF-Y is a ubiquitous protein involved in cell proliferation
composed of three subunits (-YA -YB -YC) all required for the DNA binding and
transactivation activity. To get clues on new NF-Y partner(s) we performed a mass
spectrometry screening of proteins that co-precipitate with the regulatory subunit
of the complex, NF-YA. By this screening we identified lamin A as a novel putative
NF-Y interactor. Co-immunoprecipitation experiments and confocal analysis confirmed
the interaction between the two endogenous proteins. Interestingly, this association
occurs on euchromatin regions, too. ChIP experiments demonstrate lamin A
enrichment in several promoter regions of cell cycle related genes in a NF-Y dependent
manner. Gain and loss of function experiments reveal that lamin A counteracts NF-Y
transcriptional activity. Taking advantage of a recently generated transgenic reporter
mouse, called MITO-Luc, in which an NF-Yâdependent promoter controls luciferase
expression, we demonstrate that lamin A counteracts NF-Y transcriptional activity
not only in culture cells but also in living animals. Altogether, our data demonstrate
the occurrence of lamin A/NF-Y interaction and suggest a possible role of this protein
complex in regulation of NF-Y function in cell proliferatio
Increased Incidence of T-Cell Malignancies in Patients with Chronic Lymphocytic Leukemia
We present a patient with chemotherapy-refractory Chronic Lymphocytic Leukemia (CLL) in whom postmortem examination showed hepatosplenomegaly, with both multiple small-cellular CLL lesions and large-cellular, monoclonal T-cell infiltrates. Following this case, the co-incidence of T-cell malignancies and CLL was studied using Dutch and American cancer registry databases. Analysis showed an excess risk for T-cell malignancies in CLL patients, with increased standardized incidence ratios compared with the general population and all cancer survivors in the databases. We hypothesize that CLL cells interact with T-cells in the microenvironment, facilitating malignant transformatio
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