Archive of Medical Research

Post-Traumatic Reactions in Adolescents: How Well Do the DSM-IV PTSD Criteria Fit the Real Life Experience of Trauma Exposed Youth?

This study examined the structure and symptom specific patterns of post traumatic distress in a sample of 1,581 adolescents who reported exposure to at least one traumatic event. Symptom reporting patterns are consistent with past literature in that females reported more symptoms than males and older youth reported more symptoms than did their younger peers. Young people reporting exposure to exclusively violent type traumas were also found to be more likely to endorse symptoms than peers exposed exclusively to non violent type traumas. Confirmatory factor analysis provided stronger support for a four-factor model of PTSD than either the DSM-IV model or an alternate model. Further examination of the four factor model revealed gender differences in factor loadings with small to moderate effect sizes for recurrent, distressing memories, flashbacks, restricted affect, difficulty remember details, detachment, limited future orientation, hypervigilance and startle symptoms. Differences in factor loadings with the four factor model were also noted between younger and older adolescents, with medium to large effect sizes on the arousal items. In contract, comparison of the factor loadings revealed only small differences between youth exposed exclusively to violent traumatic stressors and those exposed exclusively to non violent traumatic stressors, suggesting relative similarity between these two groups.

Saul AL, Grant KE, Carter JS.

Department of Psychology, DePaul University, 2219 N. Kenmore Ave., Chicago, IL, 60614, USA, asaul@depaul.edu.

The Development of Hyperactive-Impulsive Behaviors During the Preschool Years: The Predictive Validity of Parental Assessments.

The objectives of this study were to establish the different developmental trajectories of hyperactive-impulsive behaviors on the basis of both mother and father ratings at 19, 32, 50, and 63 months, and to examine the predictive validity of these trajectories with respect to later hyperactive-impulsive behaviors, as rated by teachers in the first 2 years of school. Hyperactive-impulsive behaviors were assessed in a population-based sample of 1,112 twins (565 boys and 547 girls) at 19, 32, 50, and 63 months of age. The results revealed a differentiated and consistent view of developmental trajectories of hyperactive-impulsive behaviors derived from these repeated assessments, with 7.1% of children seen by mothers (7% for fathers) as displaying high and stable hyperactive-impulsive behaviors. According to mother ratings, children on a high-chronic trajectory were more likely than other children to display hyperactive-impulsive behaviors at 72 and 84 months according to their teachers. Repeated measures over time and father-based trajectories significantly added to the prediction teacher later ratings of hyperactive-impulsive behaviors. These results support the predictive validity of parental assessment of hyperactive-impulsive behaviors during the preschool years and their use to identify children at risk for further evaluation and possible intervention.

Leblanc N, Boivin M, Dionne G, Brendgen M, Vitaro F, Tremblay RE, Pérusse D.

GRIP, School of Psychology, Université Laval, Québec, QC, Canada, G1K 7P4.

Common Processes in Evidence-Based Adolescent HIV Prevention Programs.

Dissemination of evidence-based HIV prevention programs for adolescents will be increased if community interventionists are able to distinguish core, essential program elements from optional, discretionary ones. We selected five successful adolescent HIV prevention programs, used a qualitative coding method to identify common processes described in the procedural manuals, and then compared the programs. Nineteen common processes were categorized as structural features, group management strategies, competence building, and addressing developmental challenges of adolescence. All programs shared the same structural features (goal-setting and session agendas), used an active engagement style of group management, and built cognitive competence. Programs varied in attention to developmental challenges, emphasis on behavioral and emotional competence, and group management methods. This qualitative analysis demonstrated that successful HIV programs contain processes not articulated in their developers\’ theoretical models. By moving from the concrete specifics of branded interventions to identification of core, common processes, we are consistent with the progress of \”common factors\” research in psychotherapy.

Ingram BL, Flannery D, Elkavich A, Rotheram-Borus MJ.

Graduate School of Education and Psychology, Pepperdine University, Los Angeles, CA, USA.

New concepts in understanding and modulating atrial repolarisation in patients with atrial fibrillation.

Atrial fibrillation is the most frequent cardiac arrhythmia in clinical practice. Although much has been learned, the underlying mechanisms are incompletely understood. Clinically used antiarrhythmic drugs are limited in their efficacy to terminate atrial fibrillation or to maintain sinus rhythm and were associated with substantial toxicity including life-threatening ventricular arrhythmias. Novel therapeutic approaches suggest targeting of atrium-selective ion channels and pathology-specific alterations in atrial repolarisation and arrhythmogenesis as promising drug targets for patients with atrial fibrillation. This article focuses on novel aspects of altered atrial repolarisation and discusses atrium-selective (I(Kur), I(K,ACh)) and pathology-specific (I(K,ACh)) ion channels as potential targets for safe and effective treatment of atrial fibrillation.

Dobrev D.

Department of Pharmacology and Toxicology, Dresden University of Technology, Fetscherstr. 74, 01307, Dresden, Germany, dobrev@rcs.urz.tu-dresden.de.

SOCS-1 Inhibits TNF-alpha-Induced Cardiomyocyte Apoptosis via ERK1/2 Pathway Activation.

Tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine involved in mitogen-activated protein kinase (MAPK) signaling pathways, contributes to the pathogenesis of cardiovascular diseases. Recently, suppressor of cytokine signaling-1 (SOCS-1) has been shown to modulate responses to TNF-alpha. However, whether SOCS-1 suppresses TNF-alpha-dependent apoptotic processes in cardiomyocytes and whether MAPK pathways mediate this effect have not been clearly elucidated. This study was carried out to define the role of SOCS-1 on TNF-alpha-induced apoptosis in neonatal rat cardiomyocytes and to investigate the signal pathways involved. Exposure to TNF-alpha (10 ng/ml for 24 h) significantly increased the number of apoptotic cells, the activity of caspase-8 and caspase-3, and the Bax/Bcl-xl ratio. In contrast, adenovirus-mediated gene transfer of SOCS-1 reversed the pro-apoptotic effect of TNF-alpha. Additionally, preincubation of cardiomyocytes with the extracellular signal-regulated kinase-1 and -2 (ERK1/2) inhibitor PD98059 attenuated the protective effect of SOCS-1, but the p38-MAPK inhibitor SB203580 and the c-Jun amino-terminal kinase (JNK) inhibitor SP600125 had no effect. Furthermore, the TNF-alpha-induced decrease in the phosphorylation of ERK1/2 was abolished by overexpression of SOCS-1. These findings suggest that SOCS-1 prevents TNF-alpha-induced apoptosis in cardiac myocytes via ERK1/2 pathway activation.

Yan L, Tang Q, Shen D, Peng S, Zheng Q, Guo H, Jiang M, Deng W.

Department of Cardiology, Renmin Hospital of Wuhan University School of Medicine, 238 JieFang Road, Wuchang, Wuhan, 430060, People’s Republic of China.

Size Distribution and Molecular Associations of Plasma Fibronectin and Fibronectin Crosslinked by Transglutaminase 2.

Fibronectin (FN) is a ubiquitously expressed cell adhesion protein capable of assembling into large, extended fibrillar networks as part of an extracellular matrix (ECM) that regulates cell behavior. FN is a substrate for certain members of the transglutaminase family of protein-crosslinking enzymes-enzymes which can modify the ability of FN to support cell adhesion. In this study, we have analyzed the thermo-chemical stability of plasma FN in its noncrosslinked form, and after crosslinking by transglutaminase 2 (TG2), using dynamic light scattering. We report that FN is found in a generally globular (8.7 nm hydrodynamic radius), dimerized form in aqueous solutions, but unfolds into a linear arrangement at high ionic (1 M NaCl) and chaotropic (5 M urea) environments. FN conformation remained stable after multiple heating and cooling cycles ranging from 4 to 60 degrees C. Crosslinking of FN with TG2 formed large, multimeric complexes having high chemical stability in aqueous, high ionic and chaotropic environments, demonstrating that this covalent modification stabilizes FN. Given recent data that substrate (e.g. ECM) rigidity profoundly affects cell differentiation and behavior, we further studied how TG2 crosslinking affects the molecular rigidity of FN by obtaining atomic force microscopy nanoindentation measurements from untreated and crosslinked FN samples embedded in acrylamide gels. We demonstrate that TG2-mediated crosslinking of FN significantly increases Young\’s modulus (of elasticity), an observation of increased rigidity having important implications with respect to the biological role of ECM protein-crosslinking in cell signaling and guiding cell differentiation.

Nelea V, Nakano Y, Kaartinen MT.

Faculty of Dentistry, McGill University, Montreal, QC, Canada, H3A 2B2.

Fluorescence Quenching of Substituted Polyperylene with Functionalized Polythiophenes.

The present investigation focuses the influence of polythiophene i) containing hetero aromatic structures and ii) containing mesogenic groups towards the photoluminescence properties of substituted polyperylene (PPE). The structural contribution towards the optical properties was individually discussed. The photoluminescence of PPE was quenched to the maximum level (30%) when it was blended with polythiophene with mesogenic groups containing longer alkyl spacer. Results of the same blend in solid-state shows 85% of PL quenching.

Ravichandar R, Thelakkat M, Somanathan N.

Polymer Laboratory, Central Leather Research Institute, Adyar, Chennai, 600020, India.

Cellular Uptake of Fluorescent Labelled Biotin-Streptavidin Microspheres.

Amino functionalized, cross-linked, polystyrene microspheres were covalently loaded with streptavidin to which was coupled fluorescently labeled biotin and biotinylated-tagged DNA. These biotin-streptavidin microsphere conjugates were then successfully delivered into cells. The application of the streptavidin-biotin technology to these microspheres allows the effective delivery of any biotinylated material into intact mammalian cells, without the need for delicate procedures such as micro-injection.

Bradley M, Alexander L, Sanchez-Martin RM.

Chemical Biology Section, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, EH9 3JJ, Edinburgh, UK.

Optimization of Verapamil Drug Analysis by Excitation-Emission Fluorescence in Combination with Second-order Multivariate Calibration.

Excitation emission fluorescence matrices (EEMs) of Verapamil drug were obtained by direct and by derivatization fluorescence spectroscopy. The fluorescence excitation and emission wavelengths were displaced to longer wavelengths and the fluorescence intensity was enhanced upon derivation with respect to the native fluorescence of the drug. The complete EEM of the native fluorescence of the drug and of the derivatization product were rapidly acquired by using a charged-coupled device detector (CCD), which is advantageous in terms of speed in the analysis, with respect to the use of a conventional photomultiplier detector. The EEMs were analyzed by several second-order multivariate calibration methods exploiting the second order advantage. The three-dimensional decomposition methods used, based in different assumptions about the trilinearity of the three way data structure under analysis, were parallel factor analysis (PARAFAC), bilinear least squares (BLLS), parallel factor analysis 2 (PARAFAC2) and multivariate curve resolution-alternating least squares (MCR-ALS). The determination was performed by using the standard addition approach. The figures of merit of the PARAFAC and BLLS methods were calculated, obtaining a lower limit of detection with the derivatization procedure, when compared with the direct measurement of the fluorescence of the drug. In Verapamil drug the best estimations were found with the BLLS and the MCR-ALS models. In the quantification of Verapamil in a pharmaceutical formulation the best estimation, when compared with the result obtained by the US Pharmacopeia high performance liquid chromatography approach, was obtained by direct fluorescence spectroscopy with MCR-ALS and by derivatization fluorescence spectroscopy with the PARAFAC2 model.

Leitão JM, Esteves da Silva JC, Girón AJ, Muñoz de la Peña A.

Centro de Estudos Farmacêuticos, Laboratório de Métodos Instrumentais de Análise, Faculdade de Farmácia da Universidade de Coimbra, 3000–432,, Coimbra, Portugal.

Cardiac Arrest Following Adjustment of a Gastric Band.

Laparoscopic adjustable gastric banding is an established and popular technique for achieving weight loss in the morbidly obese. It is however not without risks of morbidity and even mortality. The authors present a case report of a 46-year-old female who had a cardiac arrest after adjustment of a gastric band. The pathomechanisms to explain this event are explored and a review of the available literature is undertaken.

Oluigbo N, Fallouh B, Suresh V.

Department of Medicine, Birmingham Heartsland Hospital, Heart of England NHS Trust, Bordesley Green, Birmingham, B9 5ST, UK.