In vivo and in vitro developmental toxicity in LPS-induced zinc-deficient rabbits

Adenosine, produced from the decomposition of adenosine triphosphate, is believed to provide protective effects during ischemia. On the other hand, adenosine metabolites may serve as precursors for oxygen free radical formation. The time course of formation of adenosine and its purine metabolites was studied during retinal ischemia in rats. Concentrations of adenosine and its purine nucleoside metabolites inosine, hypoxanthine, and xanthine in the retina-choroid of ketamine/xylazine-anesthetized rats were measured during retinal ischemia using high performance liquid chromatography. Quantitative measurements were made possible in the small tissue mass through the use of internal standards. Ischemia was induced by ligation of the central retinal artery. In each rat, one eye was ischemic while the other served as a non-ischemic control. Eyes were frozen in situ at 1, 5, 10, 20, 30, 60, and 120 min of ischemia. The retina-choroid was then removed from the frozen eyes and analysed. Significant increases in the concentrations of adenosine, inosine, and hypoxanthine in ischemic compared to control retina-choroid were detectable within 1 to 5 min of the onset of ischemia, and within 10 min for xanthine. Increase in adenosine concentration in ischemic relative to control retina-choroid plateaued at 30 min of ischemia, while inosine and hypoxanthine concentrations increased continuously. The increase in xanthine concentration was exponential throughout the measurement period. This study documented the time-related changes in purine nucleoside concentration during ischemia. Prolonged ischemia results in ongoing production of xanthine, which by serving as a precursor for oxygen free radical formation, could be a pathogenic factor in prolonged retinal ischemia.     

Are trauma victims susceptible to "false memories?"

Laboratory studies using word-list paradigms have provided evidence that nontraumatized individuals falsely recall or recognize events that never occurred. In the present study, H. L. Roediger and K. B. McDermott's false-memory paradigm (1995) was utilized to examine possible source monitoring deficits in individuals with PTSD. Traumatized individuals with PTSD were compared with traumatized individuals without PTSD and with nontraumatized control participants. Participants heard lists of related words (e.g., bed, night) that were associates of a critical nonpresented word (e.g., sleep) and were given immediate free recall and later recognition tests. Traumatized participants with and without PTSD generated more false recalls of critical nonpresented words than did nontraumatized participants. False recall was related to trait anxiety and PTSD severity. The results are consistent with a general source-monitoring deficit in trauma-exposed individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Novel Cartesian Plot Analysis for Fixed Monolayers That Relates Cell Phenotype to Transfer of Contents between Fibroblasts and Cancer Cells by Cell-Projection Pumping

We recently described cell-projection pumping as a mechanism transferring cytoplasm between cells. The uptake of fibroblast cytoplasm by co-cultured SAOS-2 osteosarcoma cells changes SAOS-2 morphology and increases cell migration and proliferation, as seen by single-cell tracking and in FACS separated SAOS-2 from co-cultures. Morphological changes in SAOS-2 seen by single cell tracking are consistent with previous observations in fixed monolayers of SAOS-2 co-cultures. Notably, earlier studies with fixed co-cultures were limited by the absence of a quantitative method for identifying sub-populations of co-cultured cells, or for quantitating transfer relative to control populations of SAOS-2 or fibroblasts cultured alone. We now overcome that limitation by a novel Cartesian plot analysis that identifies individual co-cultured cells as belonging to one of five distinct cell populations, and also gives numerical measure of similarity to control cell populations. We verified the utility of the method by first confirming the previously established relationship between SAOS-2 morphology and uptake of fibroblast contents, and also demonstrated similar effects in other cancer cell lines including from melanomas, and cancers of the ovary and colon. The method was extended to examine global DNA methylation, and while there was no clear effect on SAOS-2 DNA methylation, co-cultured fibroblasts had greatly reduced DNA methylation, similar to cancer associated fibroblasts.     

Nanocrystalline β-Ti alloy with high hardness,low Young's modulus and excellent in vitro biocompatibility for biomedical applications

High strength, low Young's modulus and good biocompatibility are desirable but difficult to simultaneously achieve in metallic implant materials for load bearing applications, and these impose significant challenges in material design. Here we report that a nano-grained β-Ti alloy prepared by high-pressure torsion exhibits remarkable mechanical and biological properties. The hardness and modulus of the nano-grained Ti alloy were respectively 23% higher and 34% lower than those of its coarse-grained counterpart. Fibroblast cell attachment and proliferation were enhanced, demonstrating good in vitro biocompatibility of the nano-grained Ti alloy, consistent with demonstrated increased nano-roughness on the nano-grained Ti alloy. Results suggest that the nano-grained β-Ti alloy may have significant application as an implant material in dental and orthopedic applications.     

Cytokine regulation of granulocyte-macrophage colony stimulating factor and macrophage colony-stimulating factor production in human arterial smooth muscle cells

Smooth muscle cells (SMC) are the major cell type found in the walls of large blood vessels and appear to participate in local immune and inflammatory reactions, as well as in certain vascular diseases. We tested whether human arterial SMC can produce in vitro the colony stimulating factors (CSFs), granulocyte macrophage-CSF (GM-CSF) and macrophage CSF (M-CSF). Untreated internal mammary artery and aortic SMC produced no detectable GM-CSF but constitutively made M-CSF, measured by ELISA and radioimmunoassay, respectively. Interleukin-1 (IL-1) and, to a lesser extent, tumor necrosis factor alpha (TNF alpha) stimulated GM-CSF formation within 3 h; mRNA levels also increased particularly in the presence of the protein synthesis inhibitor, cycloheximide. IL-1, TNF alpha and, in addition, interferon-gamma (IFN-gamma) raised the M-CSF levels within 6 h; cycloheximide potentiated the effects of IL-1 and TNF alpha on mRNA levels. These results suggest that cytokine-stimulated human arterial SMC may be a source of the M-CSF found in atherosclerotic lesions. Since monocytes/macrophages can be activated by GM-CSF and M-CSF, while GM-CSF can also affect granulocyte function, SMC may participate in inflammatory reactions and vascular diseases by releasing these cytokines.     

Frequency Assignment Games and Strategies

The way the spectrum is committed through the processes of allocation and assignment has a definite bearing on spectrum utilization. Both processes are stochastic in nature and nearly irreversible. Decisions are made with respect to each applicant as time progresses without knowing the requirements of future applicants, and it is difficult, if not impossible, to revoke or change an assignment once given. This paper examines the frequency assignment game to determine the effect of assignment strategy on spectrum utilization, and to define the principle underlying the development of optimum strategies. The results of this investigation show that there is an effect of strategy, that the effect bears on spectrum utilization, that there is an optimum strategy, and that there are some very useful near-optimum ones as well. Finally, there is evidence that we may not be doing things quite the right way, and some recommendations are offered.     

Public acceptance of renewable energies: Results from case studies in Germany

This article addresses the public acceptance of certain renewable energies (grid-connected larger PV ground-installed systems, biomass plants and wind turbines) from a socio-scientific perspective. Using an environmental–psychological approach to investigate the social factors relevant to the formation of public acceptance towards renewable energies in four different regions, recommendations for the further implementation of renewable energy systems were to be derived. The present study has been conducted in a multi-modal research design combining a standardised questionnaire and qualitative interviews and focused on the residents’ views and perceptions. Especially within the quantitative analyses, the results indicate that economic consideration of the respective renewable energy system, understood as a positive cost–benefit calculation made by the individual, is the strongest predictor for a reported acceptance. Furthermore, the importance of landscape evaluation and a strong connection between procedural justice criteria, such as transparency, early and accurate information as well as possibilities to participate during the planning and installation process, and a reported public acceptance became evident. Qualitative data were analysed in reference to the grounded theory and showed the relevance of the operating company's commitment on the local level, participation of the general public and the choice of the location for the plant were among the relevant aspects for acceptance in the implementation process.     

Teaching trauma-focused exposure therapy for PTSD: Critical clinical lessons for novice exposure therapists.

Over the past 10 years, our experiences delivering exposure therapy and teaching clinicians to deliver exposure therapy for posttraumatic stress disorder (PTSD) have taught us some important lessons. We will focus on lessons learned as we have attended to clinicians' experiences as they begin to implement and apply the therapy. Specifically, we highlight common therapist expectations including the beliefs that the exposure therapy requires a new set of clinical skills, therapists themselves will experience a high level of distress hearing about traumatic events, and clients will become overly distressed. We then discuss common clinical challenges in the delivery of exposure therapy and illustrate them with case examples. The challenges addressed include finding the appropriate level of therapist involvement in session, handling client distress during treatment, targeting in-session covert avoidance, and helping the client shift from being trauma-focused to being more present and future oriented. Clinicians training exposure therapists and therapists new to the implementation of exposure therapy for PTSD should find this practical discussion of common expectations and initial clinical challenges reassuring and clinically useful. (PsycINFO Database Record (c) 2011 APA, all rights reserved)