Reasons adolescents don't use drugs: exploring a "depth of acceptance" model

Adolescent's reasons for not using drugs were examined for evidence of factors that might lead to differential resistance to drug use. Six thousand eight-hundred and forty-one sixth, eighth, tenth, and twelfth grade students were administered a comprehensive drug survey which included: 1) demographic information, 2) reasons not to use drugs, and 3) self-reports of lifetime and current (30-day) drug use across sixteen drug categories. The reasons for not using drugs were then factor analyzed and the results compared to a "Depth of Acceptance" (DOA) model consisting of four orientations: External Outcome, Social, and Personal. These orientations are thought both to represent distinct immunization factors and to be differentially related in strength to lifetime and current drug use. Confirmatory factor analysis revealed a close fit between the hypothesized orientations and factor loadings among the sixteen items. Collectively, the sixteen items were also found to be excellent predictors of both lifetime and current drug use. While multiple stepwise regression analyses did reveal differential predictive strengths between orientation and drug use, the misclassification of a single item apparently attenuated the results for Social Orientation. The DOA model appears to provide a useful framework for "fine-tuning" prevention messages based on factors that immunize against drug use.     

Discarded needles do not increase soon after the opening of a needle exchange program

This study examines the effect of a Needle Exchange Program (NEP) on the quantity and geographic distribution of discarded needles on the streets of Baltimore, Maryland, and presents methods to survey discarded needles in the community. A random sample of 32 city blocks located within high-drug-use census tracts, stratified by east and west sides of the city and by proximity to the NEP, was selected for survey. Three teams surveyed the number of needles and the number of drug vials and unbroken glass bottles ("trash") to control for practice effects. Surveillance was conducted prior to initiation of the NEP in August 1994 and 1 and 2 months thereafter. Over the three study periods, the absolute count of discarded needles was 106, 130, and 128, respectively; the number of vials and bottles was 3,048, 3,825, and 3,796, respectively. The initial nonstatistically significant increase in needles (mean change = 0.38, 95% confidence interval (CI) -0.18 to 0.93) was offset by accounting for background trash. Regression models fitted with the generalized estimating equation method, which accounted for within-block correlation over time, showed no significant increase in the number of needles after adjustment for trash during the first 2 months of the NEP's operation. These data suggest that the initiation of NEPs does not result in an increase in the number of discarded needles on the street.     

Neuropsychiatric manifestations following the use of 3,4-methylenedioxymethamphetamine (MDMA: "Ecstasy")

1. The recurring side-effects associated with MDMA consumption are reviewed. 2. The recreational use of "Ecstasy" has been implicated in the onset of various psychological, neurological, and organic complications. A table has been employed to depict the deleterious reactions that have occurred following MDMA ingestion. 3. An original case report is presented in which an individual developed perpetual neuropsychiatric symptomatology after having consumed MDMA. This case indicates that MDMA may induce long lasting effects, even after one exposure.     

Lobectomy combined with volume reduction for patients with lung cancer and advanced emphysema

Methanol-induced conformational transitions of hen egg white lysozyme were investigated with a combined use of far- and near-UV CD and NMR spectroscopies, ANS binding and small-angle X-ray scattering. Addition of methanol induced no global change in the native conformation itself, but induced a transition from the native state to the denatured state which was highly cooperative, as shown by the coincidence of transition curves monitored by the far- and near-UV CD spectroscopy, by isodichroic points in the far- and near-UV CD spectra and by the concomitant disappearance of individual 1H NMR signals of the native state. The ANS binding experiments could detect no intermediate conformer similar to the molten globule state in the process of the methanol denaturation. However, at high concentration of methanol, e.g., 60% (v/v) methanol/water, a highly helical state (H) was realized. The H state had a helical content much higher than the native state, monitored by far-UV CD spectroscopy, and had no specific tertiary structure, monitored both by near-UV CD and NMR spectroscopy. The radius of gyration in the H state, 24.9 angstroms, was significantly larger than that in the native state (15.7 angstroms). The Kratky plot for the H state did not show a clear peak and was quite similar to that for the urea-denatured state, indicating a complete lack of globularity. Thus we conclude that the H state has a considerably expanded, flexible broken rod-like conformation which is clearly distinguishable from the "molten globule" state. The stability of both N and H states depends on pH and methanol concentration. Thus a phase diagram involving N and H was constructed.     

Double-stranded deoxyribonucleic acid binds to HLA class II molecules and inhibits HLA class II-mediated antigen presentation

CD4+ T cells proliferating in response to purified double-stranded deoxyribonucleic acid (dsDNA) have been recently demonstrated in peripheral blood mononuclear cells of patients with systemic lupus erythematosus. Their activation was inhibited by anti-HLA class II (HLA-II) monoclonal antibodies; thus, the existence of a molecular interaction between dsDNA and HLA-II is conceivable. In this report we show that dsDNA specifically bind to HLA-II. After preincubating cells with purified dsDNA or synthetic oligonucleotides, dsDNA was detected on the cell membrane and in the lysates of HLA-II+ but not of isogenic HLA-II- cell lines. We demonstrate that dsDNA binding inhibits that of a specific peptide to HLA-II. Mixed lymphocyte reaction and antigen-specific T cell proliferation were inhibited by the preincubation of stimulator cells or antigen-presenting cells with dsDNA. These results suggest the existence of a novel mechanism of down-modulation of the CD4+ T cell function generated by lack of stimulation due to the HLA-II presenting molecules being "occupied" by dsDNA.     

Physiological compensation in antisense transformants: specific induction of an "ersatz" glucan endo-1,3-beta-glucosidase in plants infected with necrotizing viruses

Plant class I glucan endo-1,3-beta-glucosidases (beta-1,3-glucanase; 1,3-beta-D-glucan glucanohydrolase, EC 3.2.1.39) have been implicated in development and defense against pathogen attack. Nevertheless, beta-1,3-glucanase deficiencies generated by antisense transformation of Nicotiana sylvestris and tobacco have little biological effect. We report here that another beta-1,3-glucanase activity is induced in these deficient mutants after infection with necrotizing viruses. Induction of class I beta-1,3-glucanase was markedly inhibited in leaves of N. sylvestris and tobacco antisense transformants infected with tobacco necrosis virus and tobacco mosaic virus, respectively. A serologically distinct beta-1,3-glucanase activity was present in the infected antisense transformants but was absent in both healthy and infected control plants and in antisense transformants treated with the stress hormone ethylene. Immunoblot analyses, localization studies, and measurements of antibody specificity indicate that this compensatory beta-1,3-glucanase activity is an intracellular enzyme different from known tobacco beta-1,3-glucanases. Therefore, plants can compensate for a deficiency in enzyme activity by producing a functionally equivalent replacement--i.e., "ersatz"--protein or proteins. The fact that compensation for beta-1,3-glucanase activity occurs in response to infection argues strongly for an important role of these enzymes in pathogenesis.     

Measuring and modeling reduction of DDT availability to the water column and mussels following activated carbon amendment of contaminated sediment

A 28-day accumulation study demonstrated the use of mussel uptake, passive samplers, and biodynamic modeling to measure the reduction of dichlorodiphenyltrichloroethane (DDT) availability in the water column after the addition of activated carbon to contaminated sediment. Sediment collected from Lauritzen Channel, Richmond, California (16.5 mg total DDT/kg) was mixed with either virgin activated carbon or a reactivated carbon for one month, after which a 28-day laboratory exposure study was completed. Mussels (Mytilus edulis) suspended above activated carbon-treated sediment accumulated significantly less total DDT in soft tissue, 91% and 84% for virgin and reactivated carbon, respectively, as compared to untreated sediment. Mussel tissue concentrations correlated to concentrations in semipermeable membrane devices (SPMDs) and polyethylene devices (PEDs) suspended over the same sediments. A biodynamic model that incorporated DDT water concentrations, either analytically measured or estimated from PED uptake, described mussel accumulation over time. Thus, passive samplers in combination with biodynamic modeling may provide an important screening tool for assessment of filter-feeding uptake and ecological risk to water-dwelling organisms exposed to aqueous phase hydrophobic organic contaminants.     

On-line separation and determination of bromate in drinking waters using flow injection ICP mass spectrometry

A flow injection (FI) system with a microcolumn of anion exchanger has been used to effect rapid on-line separation of bromate and bromide prior to quantitation by ICP mass spectrometry. Basic performance studies are described including the effect of key FI parameters, i.e., sample injection volume, carrier stream flow rate, and eluent concentration on system response. The new approach permitted ultratrace determinations of bromate in drinking waters, the main benefits being low limit of detection (0.13 microg/L based on a 500-microL sample injection), rapid analysis time (10 min/sample), and good precision (2.8% at the 5 microg/L level). Accuracy was checked via an EC-sponsored interlaboratory trial.     

Synthesis and characterization of 15% efficient CIGSSe solar cells from nanoparticle inks

We report a total‐area power conversion efficiency of 15% for a copper indium gallium disulfoselenide (CIGSSe) solar cell fabricated from a copper indium gallium disulfide (CIGS) nanoparticle ink based process. Careful optimization of the fabrication process has resulted in a significant improvement in efficiency compared to our previously reported efficiency of 12%. This efficiency ranks among the highest reported in the literature for solution processed CIGSSe. Despite having an absorber thickness of approximately 700–800 nm, which is less than half the thickness of high efficiency devices grown by both coevaporation and solution processes in the literature, our devices show good short‐circuit current (32.1 mA/cm²). Surprisingly, the sintered film shows lateral composition fluctuations, which have not been reported for other high efficiency devices and may be responsible for the lower open circuit voltage (636 mV) observed here. This suggests an avenue for further improvement through optimization of the nanoparticle selenization process to better control composition in the sintered film. Copyright © 2015 John Wiley & Sons, Ltd.