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We measured the relationships between choice stimulus modalities and three basic discriminations (visual, visual matching-to-sample, and auditory-visual) using the Assessment of Basic Learning Abilities test. Participants were 9 adults who had moderate to profound developmental disabilities. Their most and least preferred leisure activities, identified by prior preference assessments, were presented using choice stimuli in three modalities (tangibles, pictures, and verbal descriptions) in an alternating-treatments design. For 8 of the 9 participants, discrimination skills predicted the selections of choice stimuli associated with their preferred activities. The results suggest that choice stimulus modalities in preference assessment of leisure activities need to be matched to the discrimination skills of persons with developmental disabilities.

The majority of human melanomas harbor activating mutations in either the BRAF or NRAS gene. To date, the role of oncogenic NRAS in melanoma remains poorly defined and no current therapies are directed at specifically suppressing oncogenic NRAS in human melanoma tumors. The aim of our study, therefore, was to investigate the effects of suppressing oncogenic NRAS in human melanoma cell lines in vitro. Using both small interfering RNA- and plasmid based-RNA interference techniques, oncogenic NRAS was specifically suppressed in 2 human melanoma cell lines, 224 and BL, which harbor a codon 61 CAA (glutamine) to CGA (arginine) NRAS mutation. Suppression of oncogenic NRAS in these cell lines resulted in increased apoptosis. Furthermore, in 224 cells we demonstrated decreased phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, and reduced expression of NF-κB and cyclin D1 in the N-Ras signaling pathway. In contrast, RNA interference directed at wild-type (WT) NRAS had no significant effect on apoptosis of 224 cells or 2 human melanoma cell lines (A375 and 397) containing WT NRAS but a codon 600 GTG (valine) to GAG (glutamate) mutation in BRAF. These data suggest that oncogenic NRAS is important for avoidance of apoptosis in melanomas that harbor the codon 61 NRAS mutation and emphasizes oncogenic NRAS as a therapeutic target in patients with tumors that harbor this mutation. © 2005 Wiley-Liss, Inc.

The Assessment of Basic Learning Abilities test (ABLA) is a useful tool for choosing appropriate training tasks for persons with developmental disabilities. This test assesses the ease or difficulty with which persons are able to learn six hierarchically positioned discrimination tasks. A visual-visual nonidentity matching prototype task was examined to assess its (a). relation to the ABLA hierarchy, (b). predictive validity, and (c). test-retest reliability. Results from 23 participants with developmental disabilities suggest that visual-visual nonidentity matching is a worthwhile addition to the ABLA test and is positioned in the ABLA hierarchy above Level 4 (visual-visual identity matching) and below Level 6 (auditory-visual discrimination). The prototype visual-visual nonidentity matching task also demonstrated high predictive validity and test-retest reliability.

In this study, we examined whether versican, a recognized anti-cell adhesive molecule for various mesenchymal and nerve cell types, influences prostate cancer cell adhesion to extracellular matrix components. Prostate cancer cell adhesion to fibronectin, a major component of the stromal extracellular matrix was inhibited by versican-rich conditioned medium (CM) from cultured human prostatic fibroblasts. In contrast, cancer cell attachment to laminin, a component of basement membranes, was not affected by the same CM. Consistent with versican being the active inhibitory factor in the CM, the integrity of chondroitin sulfate side chains and an ability to bind the RGD (Arg-Gly-Asp) peptide sequence of fibronectin were essential for the inhibition of prostate cancer cell attachment to fibronectin. Subsequent studies with versican purified from human prostate fibroblast CM confirmed its anti-adhesive activity. We conclude that versican is an important modulator of tumor cell attachment to the interstitial stromal matrix of the prostate, the latter being an essential step in cancer cell motility and local invasion of the prostatic stroma.

Determination of meaningful prognostic indicesremains a high priority for women diagnosed with node-negative primary breast cancer. Currently, 30% of these women relapse, and there is no reliable means of predicting this group of patients. This study investigates whether the level of expression of versican, an anticell adhesive proteoglycan, in the peritumoral stromal tissue of women with node-negative, primary breast cancer predicts relapse-free survival. This study also examines whether breast cancer cells regulate the secretion of versican by mammary fibroblasts.Immunoreactive versican was measured in breast cancer tissue sections of 58 node-negative patients by video image analysis. Primary isolates of mammary fibroblasts were cultured in medium conditioned by the breast cancer cell lines ZR-75-1, MCF-7, BT-20, and MB231. Changes in versican secretion were measured by immunoblotting and enhanced chemiluminescence.Cox analyses indicated that peritumoral versican level was the sole predictor of relapse-free survival. The relapse rate in patients with low versican levels was lower than in patients with high versican levels (Kaplan-Meier: 83% relapse free at 5 years for versican mean integrated absorbance14 versus 33% foror = 14, P = 0.0006). Accumulation of versican in medium of mammary fibroblasts was increased after culture in conditioned medium from breast cancer cell lines.Relapse in women with node-negative breast cancer is related to the level of versican deposited in peritumoral stroma by mammary fibroblasts. Versican secretion appears to be regulated by breast cancer cell mediators. Neoplastic remodeling of extracellular matrix through increased versican deposition may facilitate local invasion and metastasis.

The presence of plasmonic material influences the optical properties of nearby molecules in untrivial ways due to the dynamical plasmon-molecule coupling. We combine quantum and classical calculation schemes to study this phenomenon in a hybrid system that consists of a Na(2) molecule located in the gap between two Au/Ag nanoparticles. The molecule is treated quantum-mechanically with time-dependent density-functional theory, and the nanoparticles with quasistatic classical electrodynamics. The nanoparticle dimer has a plasmon resonance in the visible part of the electromagnetic spectrum, and the Na(2) molecule has an electron-hole excitation in the same energy range. Due to the dynamical interaction of the two subsystems the plasmon and the molecular excitations couple, creating a hybridized molecular-plasmon excited state. This state has unique properties that yield e.g. enhanced photoabsorption compared to the freestanding Na(2) molecule. The computational approach used enables decoupling of the mutual plasmon-molecule interaction, and our analysis verifies that it is not legitimate to neglect the back coupling effect when describing the dynamical interaction between plasmonic material and nearby molecules. Time-resolved analysis shows nearly instantaneous formation of the coupled state, and provides an intuitive picture of the underlying physics.

We have previously demonstrated that peritumoral stromal matrix derived from prostate cancer patients who relapse after radical surgery contains elevated levels of versican. The purpose of this study was to determine whether prostate cancer cells control stromal cell secretion of versican. Serum-free conditioned medium from three prostate adenocarcinoma cell lines, LNCaP, PC3, and DU145, was added to cultures of fibroblasts established from prostatic tissue of patients with benign prostatic hyperplasia, and the medium was harvested at 24, 48, and 72 h. Immunoblotting with an antiversican core protein antibody revealed that prostatic fibroblast medium harvested at 72 h contained increased levels of versican after treatment with either LNCaP-, PC3- or DU145-conditioned medium (2.5-, 4.5-, and 5-fold, respectively) compared with control cultures. This increase in versican in the culture medium was not observed after coincubation with transforming growth factor beta1-neutralizing antisera. The results of this study suggest that prostate tumor cells induce host stromal cells to secrete increased versican levels via a paracrine mechanism mediated by transforming growth factor beta1.

We present an x-ray scattering study of the temperature-induced phase separation and Si nanocrystal formation in bulk amorphous SiOx with x≈1. X-ray Raman scattering at the Si LII,III-edge reveals a significant contribution of suboxides present in native amorphous SiO. The suboxide contribution decreases with increasing annealing temperature between 800–1200 °C pointing toward a phase separation of SiO into Si and SiO2 domains. In combination with x-ray diffraction and small angle x-ray scattering the SiO microstructure is found to be dominated by internal suboxide interfaces in the native state. For higher annealing temperatures above 900 °C growth of Si nanocrystals with rough surfaces embedded in a silicon oxide matrix can be observed.

The temperature-induced phase separation (disproportionation) and Ge nanocrystal formation in bulk amorphous germanium monoxide (a-GeOx,x≈1) are studied both in situ and ex situ by measurements of the x-ray absorption near edge structure at the Ge K-edge and x-ray diffraction. The considerable amount of suboxides contained in the native a-GeO samples decreases with increasing annealing temperature. The phase separation sets in at a temperature of 260±20 °C and is almost completed at a temperature of 450±18 °C before nanocrystal formation occurs. Ge nanocrystals of a few nanometers in diameter are observed for an annealing temperature of 509±15 °C. The time dependence of the phase separation and the effect of different annealing procedures are discussed. The presented results provide important information for the production of Ge nanocrystals embedded in amorphous oxide matrices which are relevant for optoelectronic applications.

Typically, 3% to 5% of patients experience sensations of heaviness, pressure, and tightness in the chest after administration of sumatriptan, but there is little ECG evidence of ischemia. The serious cardiovascular incidents after consuming sumatriptan have been associated mostly with the subcutaneous dosage form of this drug and with patients with underlying cardiovascular risk factors. We report a case of fatal cardiac arrhythmia in an otherwise perfectly healthy patient with migraine after consuming a single 100-mg dose of oral sumatriptan.

The Assessment of Basic Learning Abilities test (ABLA) is a useful tool for choosing appropriate training tasks for persons with developmental disabilities. This test assesses the ease or ...