Interobserver agreement in assigning IOTA color score to adnexal masses using three-dimensional volumes or digital videoclips: potential implications for training.

OBJECTIVE: To estimate the interobserver agreement between a trainer and trainees in assigning the International Ovarian Tumor Analysis (IOTA) color score to adnexal masses using three-dimensional (3D) volumes and videoclips. METHODS: Fifty-one digital videoclips and 3D volumes of a non-consecutive series of adnexal masses were used for this study. One trainer and four trainees evaluated first the 3D volume and 1 week later a videoclip from the same mass. They had to assign IOTA color scores according to their impression of the amount of color content in each case. Interobserver agreement between trainer and trainees was assessed using Cohen's weighted kappa index with 95% CIs and percentage of agreement. RESULTS: When using 3D volumes, interobserver agreement was good for three out of four pairs of comparisons and very good for one (kappa values of 0.70, 0.68, 0.81 and 0.71 for trainees A, B, C and D, respectively). When using videoclips, interobserver agreement was very good for two out of four pairs of comparisons and good for two (kappa values of 0.84, 0.80, 0.68 and 0.86 for Trainees A, B, C and D, respectively). CONCLUSION: Evaluation of IOTA color scores in adnexal masses using either videoclips or 3D volumes is reproducible even in the hands of trainees after a short training program.

Daptomycin: a review of properties, clinical use, drug delivery and resistance.

Daptomycin is a branched cyclic anionic lipopeptide antibiotic that was discovered in the early 1980's but got the FDA approval only in 2003. This novel pharmaceutical molecule has demonstrated great in vitro activity against a wide range of aerobic and anaerobic gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Daptomycin has a unique mechanism of action, not completely understood, involving a calcium-dependent dissipation of membrane potential leading to the release of intracellular ions from the cell and bacteria death. This antibiotic has been already approved for the treatment of patients with complicated skin and skin structure infections, right-sided endocarditis and bacteraemia. Local delivery of daptomycin is an emerging area of study. Current in vitro studies show that daptomycin can be eluted from polymethylmethacrylate, calcium sulfate and chitosan films. Emerging cases of resistance to daptomycin have been reported, commonly occurring by spontaneous mutations, and have been associated with prolonged use, osteomyelitis, acute myeloid leukemia and leucocyte adhesion deficiency syndrome. This review examines the most recent literature evidences on daptomycin molecular structure, mechanism of action, bacterial spectrum, clinical uses, local delivery, toxicity and resistance.

Competition of copper and/or calcium in nickel-pectin interaction by potentiometric and voltammetric techniques.

The interaction between nickel and pectin extracted from citrus fruit was studied in 0.10 M KNO(3), at pH 5.5 and 25 degrees C. Differential pulse and/or square wave polarography were used to determine free nickel. For a high coverage degree (theta) of the pectin by the metal ion a good fitting was observed between experimental results and the model that includes both complex species, ML and ML(2) (M for the metal ion and L for the ligand). In the ML(2) species, Ni(II) interacts with two carboxylate groups of different chains, resulting in an inter-chain association. For low theta values, the formation of ML(2) is hindered due to the repulsion between the negative charges of carboxylic groups in two independent segments of pectin. The influence of calcium or copper ions on the free nickel concentration, in the presence of pectin, may lead to a decrease in free nickel concentration, contrary to what would be expected from direct competition between Ca(II) or Cu(II) and Ni(II) for the pectin binding sites. This is due to the partial neutralisation of the negative carboxylic charges by the positive charges of the divalent cations, which favours NiL(2) formation through the association of independent chains.

Mercury determination by FI-CV-AAS after the degradation of organomercurials with the aid of an ultrasonic field: the important role of the hypochlorite ion.

Due to new findings, the methodology based on room-temperature ultrasonic irradiation (sonolysis) for conversion of organomercurials into inorganic mercury [J.L. Capelo, I. Lavilla, C. Bendicho, Anal. Chem. 72 (2000) 4979-4984.] is further investigated. Inorganic mercury is selectively determined by Flow Injection-Cold Vapour Atomic Absorption Spectrometry (FI-CV-AAS) using SnCl(2)/HCl. Complete oxidation of methyl-mercury can be accomplished within 90 s whilst phenyl and diphenyl-mercury can be degraded within 10s using a 50% sonication amplitude (100 W nominal power) provided by a probe ultrasonic device (20.5 kHz frequency) and a 1 mol L(-1) HCl liquid medium with the presence of hypochlorite ion. The importance of hypochlorite in reduction of organomercurials by stannous chloride is highlighted. Oxidation kinetics indicated a pseudo first-order reaction for methyl-mercury, phenyl-mercury, and diphenyl-mercury.

Influence of the sediment on lead speciation in the Tagus estuary.

The aim of this work is to study the influence of the Tagus estuarine sediment on lead speciation in the overlying natural water. The water sample in the presence of the sediment was contaminated three times with Pb(II) in a laboratory experiment. In different periods of time, at 1-7 days after each contamination, small volumes of water were titrated with lead. The titration was followed by anodic stripping voltammetry in differential pulse mode. Before and after contamination systematic analysis of the voltammetric parameters (peak current, peak potential and peak width) were carried out to get a clear picture of Pb(II) complexation in the soluble fraction in contact with the sediment. Two main types of organic ligands, macromolecular ligands and small compounds, were detected before contamination. Both of them form labile complexes (degree of lability within the timescale of some milliseconds). The small compounds, with a diffusion coefficient similar to that of the free metal ion, present a homogeneous behaviour in terms of Pb complexation. On the other hand macromolecular ligands, with a diffusion coefficient of 1.2 x 10(-6) cm2s(-1), can be described by two different binding groups, which might be of phenolic and carboxylic type as presented by humic matter. The sediment eliminated lead contamination (10(-6) moldm(-3) was the maximum concentration added) from 12 dm3 of water (surface of 8 dm2) within 2 days. It was also found that the sediment released organic ligands responsible for both labile and inert Pb complexes "seen" by voltammetry. The release of organic ligands that decreases the bioavailability of Pb(II) was clearly detected 1 week after contamination. Therefore, the sediment acts as a buffer for lead through two mechanisms against lead contamination: removing lead ions from the solution and releasing organic ligands to the water column. In a short period of time the sediment responds as a self-cleaning system for Pb(II) contamination in the estuarine water, which may have a very important influence in environmental pollution.

Discussion of parameters associated with the ultrasonic solid-liquid extraction for elemental analysis (total content) by electrothermal atomic absorption spectrometry. An overview.

Ultrasonic solid-liquid extraction (USLE) of trace metals from biological and environmental samples and its subsequent quantification by electrothermal atomic absorption spectrometry (ET-AAS) is nowadays an emerging methodology in the analytical laboratory. However, this methodology is far from maturity as can be readily demonstrated from the controversial data reported by different workers. In the light of our own experience and a survey of published data, a general approach for USLE-ET-AAS is discussed, taking into account the different variables which affect ultrasonic solid-liquid extraction, namely, the ultrasonic device chosen for ultrasonic extraction (e.g. ultrasonic bath or ultrasonic probe), particle size, acid concentration, sonication time and sonication amplitude, sample mass and analyte-matrix binding.