In Vitro and In Vivo Analysis of Ochratoxin A-Derived Glucuronides and Mercapturic Acids as Biomarkers of Exposure.

Ochratoxin A (OTA) is a widespread food contaminant, with exposure estimated to range from 0.64 to 17.79 ng/kg body weight (bw) for average consumers and from 2.

The quality of COPD care in German general practice-A cross-sectional study.

Objectives: Chronic Obstructive Pulmonary Disease (COPD) is a common health problem to be dealt with in primary care. Little is known about the quality of care provided for patients with COPD in Germany. Therefore, we wanted to assess the current quality of care delivered by a primary care network (PCN) for patients with COPD.

Density discrimination with occlusions in 3D clutter.

We examined how well human observers can discriminate the density of surfaces in two halves of a rotating three-dimensional cluttered sphere. The observer's task was to compare the density of the front versus back half or the left versus right half. We measured how the bias and sensitivity in judging the denser half depended on the level of occlusion and on the area and density of the surfaces in the clutter.

A Psychophysical Evaluation of Texture Compression Masking Effects.

Lossy texture compression is increasingly used to reduce GPU memory and bandwidth consumption. However, as raised by recent studies, evaluating the quality of compressed textures is a difficult problem. Indeed using Peak Signal-to-Noise Ratio (PSNR) on texture images, like done in most applications, may not be a correct way to proceed.

Signs of depth-luminance covariance in 3-D cluttered scenes.

In three-dimensional (3-D) cluttered scenes such as foliage, deeper surfaces often are more shadowed and hence darker, and so depth and luminance often have negative covariance. We examined whether the sign of depth-luminance covariance plays a role in depth perception in 3-D clutter. We compared scenes rendered with negative and positive depth-luminance covariance where positive covariance means that deeper surfaces are brighter and negative covariance means deeper surfaces are darker.

Defocus Discrimination in Video: Motion in Depth.

We perform two psychophysics experiments to investigate a viewer's ability to detect defocus in video; in particular, the defocus that arises in video during motion in depth when the camera does not maintain sharp focus throughout the motion. The first experiment demonstrates that blur sensitivity during viewing is affected by the speed at which the target moves towards the camera. The second experiment measures a viewer's ability to notice momentary defocus and shows that the threshold of blur detection in arc minutes decreases significantly as the duration of the blur increases.

Depth discrimination from occlusions in 3D clutter.

Objects such as trees, shrubs, and tall grass consist of thousands of small surfaces that are distributed over a three-dimensional (3D) volume. To perceive the depth of surfaces within 3D clutter, a visual system can use binocular stereo and motion parallax. However, such parallax cues are less reliable in 3D clutter because surfaces tend to be partly occluded.

Examination of Substance Use, Risk Factors, and Protective Factors on Student Academic Test Score Performance.

Background: School administrators and teachers face difficult decisions about how best to use school resources to meet academic achievement goals. Many are hesitant to adopt prevention curricula that are not focused directly on academic achievement. Yet, some have hypothesized that prevention curricula can remove barriers to learning and, thus, promote achievement.

Are blur and disparity complementary cues to depth?

The image blur and binocular disparity of a 3D scene point both increase with distance in depth away from fixation. Perceived depth from disparity has been studied extensively and is known to be most precise near fixation. Perceived depth from blur is much less well understood.

Qualitative shape from shading, highlights, and mirror reflections.

The human visual system has a remarkable ability to perceive three-dimensional (3-D) surface shape from shading and specular reflections. This paper presents two experiments that examined the perception of local qualitative shape under various conditions. Surfaces were rendered using standard computer graphics models of matte, glossy, and mirror reflectance and were viewed from a small oblique angle to avoid occluding contour shape cues.

Visibility in three-dimensional cluttered scenes.

Three-dimensional (3D) cluttered scenes consist of a large number of small surfaces distributed randomly in a 3D view volume. The canonical example is the foliage of a tree or bush. 3D cluttered scenes are challenging for vision tasks such as object recognition and depth perception because most surfaces or objects are only partly visible.

Removal of partial occlusion from single images.

This paper examines large partial occlusions in an image which occur near depth discontinuities when the foreground object is severely out of focus. We model these partial occlusions using matting, with the alpha value determined by the convolution of the blur kernel with a pinhole projection of the occluder. The main contribution is a method for removing the image contribution of the foreground occluder in regions of partial occlusion, which improves the visibility of the background scene.

Learning illumination- and orientation-invariant representations of objects through temporal association.

As the orientation or illumination of an object changes so does its appearance. This paper considers how observers are nonetheless able to recognize objects that have undergone such changes. In particular the paper tests the hypothesis that observers rely on temporal correlations between different object views to decide whether they are views of the same object or not.

Palladium-catalyzed annulation of haloanilines and halobenzamides using norbornadiene as an acetylene synthon: a route to functionalized indolines, isoquinolinones, and indoles.

A general procedure for the palladium-catalyzed annulation of substituted haloanilines with norbornadiene gives functionalized indolines in 51-98% yield. These indolines can be rapidly converted to benzenoid-substituted indoles and tricyclic indolines. Extension to the use of substituted halobenzamides gives functionalized isoquinolinones in up to 86% yield.

Electrical conductance of conjugated oligomers at the single molecule level.

We determine and compare, at the single molecule level and under identical environmental conditions, the electrical conductance of four conjugated phenylene oligomers comprising terminal sulfur anchor groups with simple structural and conjugation variations. The comparison shows that the conductance of oligo(phenylene vinylene) (OPV) is slightly higher than that of oligo(phenylene ethynylene) (OPE). We find that solubilizing side groups do neither prevent the molecules from being anchored within a break junction nor noticeably influence the conductance value.

Spectrum analysis of motion parallax in a 3D cluttered scene and application to egomotion.

Previous methods for estimating observer motion in a rigid 3D scene assume that image velocities can be measured at isolated points. When the observer is moving through a cluttered 3D scene such as a forest, however, pointwise measurements of image velocity are more challenging to obtain because multiple depths, and hence multiple velocities, are present in most local image regions. We introduce a method for estimating egomotion that avoids pointwise image velocity estimation as a first step.

Probenecid interacts with the pharmacokinetics of morphine-6-glucuronide in humans.

Background: Evidence obtained from porcine cell cultures and experiments in laboratory animals indicates that transmembrane transporters may play a role in the distribution of the active morphine metabolite morphine-6-glucuronide (M6G). This was evaluated in a study in healthy volunteers.

Methods: Ten subjects received an intravenous M6G infusion for 30 min at a dosage of 0.

Substrate specificity and kinetic mechanism of the Sir2 family of NAD+-dependent histone/protein deacetylases.

The Silent information regulator 2 (Sir2) family of enzymes consists of NAD(+)-dependent histone/protein deacetylases that tightly couple the hydrolysis of NAD(+) and the deacetylation of an acetylated substrate to form nicotinamide, the deacetylated product, and the novel metabolite O-acetyl-ADP-ribose (OAADPR). In this paper, we analyzed the substrate specificity of the yeast Sir2 (ySir2), the yeast HST2, and the human SIRT2 homologues toward various monoacetylated histone H3 and H4 peptides, determined the basic kinetic mechanism, and resolved individual chemical steps of the Sir2 reaction. Using steady-state kinetic analysis, we have shown that ySir2, HST2, and SIRT2 exhibit varying catalytic efficiencies and display a preference among the monoacetylated peptide substrates.

Effects of ABCB1 (multidrug resistance transporter) gene mutations on disposition and central nervous effects of loperamide in healthy volunteers.

Objective: Mutations in the ABCB1 gene have been associated with decreased expression and net function of P-glycoprotein (P-gp). We investigated the modulation of the central nervous effects of loperamide resulting from ABCB1 genetic variants.

Methods: On two occasions, 20 healthy volunteers received 24 mg loperamide suspension orally and, in a double-blind randomized two-way crossover fashion, 800 mg quinidine or placebo orally 1 h before loperamide.

Essential role for the SANT domain in the functioning of multiple chromatin remodeling enzymes.

The SANT domain is a novel motif found in a number of eukaryotic transcriptional regulatory proteins that was identified based on its homology to the DNA binding domain of c-myb. Here we show that the SANT domain is essential for the in vivo functions of yeast Swi3p, Ada2p, and Rsc8p, subunits of three distinct chromatin remodeling complexes. We also find that the Ada2p SANT domain is essential for histone acetyltransferase activity of native, Gcn5p-containing HAT complexes.

In vitro and in vivo evaluation of a 99mTc(I)-labeled bombesin analogue for imaging of gastrin releasing peptide receptor-positive tumors.

A new radiolabeled bombesin analogue, [99mTc(I)-PADA-AVA]bombesin (7-14), was synthesized and in vitro and in vivo characterized. High affinity and rapid internalization were obtained in binding assays. A specific binding towards gastrin releasing peptide receptors-positive tissues, pancreas and tumor, was observed in CD-1 nu/nu mice bearing PC-3 prostate adenocarcinoma xenografts.

Modulating acetyl-CoA binding in the GCN5 family of histone acetyltransferases.

The histone acetyltransferase (HAT) GCN5 is the founding member for a family of chromatin remodeling enzymes. GCN5 is the catalytic subunit of a large multi-subunit complex that functions in the regulation of gene activation via acetylation of lysine residues within the N-terminal tails of core histone proteins. Using acetyl-CoA as a co-substrate, the high affinity binding of acetyl-CoA is a critical first step in the reaction.

Noncysteinyl coordination to the [4Fe-4S]2+ cluster of the DNA repair adenine glycosylase MutY introduced via site-directed mutagenesis. Structural characterization of an unusual histidinyl-coordinated cluster.

The Escherichia coli DNA repair enzyme MutY plays an important role in the recognition and repair of 7,8-dihydro-8-oxo-2'-deoxyguanosine-2'-deoxyadenosine (OG*A) mismatches in DNA. MutY prevents DNA mutations caused by the misincorporation of A opposite OG by catalyzing the deglycosylation of the aberrant adenine. MutY is representative of a unique subfamily of DNA repair enzymes that also contain a [4Fe-4S]2+ cluster, which has been implicated in substrate recognition.