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Light
Kinds of Light Terms modified by Light Selected AbstractsLymphotoxin,, receptor-Ig fusion protein treatment blocks actively induced, but not adoptively transferred, uveitis in Lewis ratsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2003Hui Shao Abstract Previous studies have shown that treatment of rodents with a lymphotoxin (LT),, receptor-Ig fusion protein (LT,R-Ig), which binds to both LT and LIGHT, prevents the development of autoimmune diseases, but the mechanism involved is unclear. To explore the potential role of LT or LIGHT in the pathogenesis of autoimmune uveitis, uveitis was induced in Lewis rats either by immunization with an uveitogenic peptide, R16, derived from the interphotoreceptor retinoid-binding protein, or by adoptive transfer of R16-specific T,cells. Interestingly, LT,R-Ig treatment completely prevented actively induced uveitis, but not the adoptively transferred disease. We also show that LT,R-Ig-treated R16-injected rats had a significantly decreased T,cell response to R16 and that herpesvirus entry mediator (HVEM)-Ig, a fusion protein that blocks LIGHT, also inhibited disease development. Our results suggest that LT or LIGHT plays a critical role in the induction, rather than the effector, phase of the disease. [source] GENOMICS IN THE LIGHT OF EVOLUTIONARY TRANSITIONSEVOLUTION, Issue 6 2010Pierre M. Durand Molecular biology has entrenched the gene as the basic hereditary unit and genomes are often considered little more than collections of genes. However, new concepts and genomic data have emerged, which suggest that the genome has a unique place in the hierarchy of life. Despite this, a framework for the genome as a major evolutionary transition has not been fully developed. Instead, genome origin and evolution are frequently considered as a series of neutral or nonadaptive events. In this article, we argue for a Darwinian multilevel selection interpretation for the origin of the genome. We base our arguments on the multilevel selection theory of hypercycles of cooperative interacting genes and predictions that gene-level trade-offs in viability and reproduction can help drive evolutionary transitions. We consider genomic data involving mobile genetic elements as a test case of our view. A new concept of the genome as a discrete evolutionary unit emerges and the gene,genome juncture is positioned as a major evolutionary transition in individuality. This framework offers a fresh perspective on the origin of macromolecular life and sets the scene for a new, emerging line of inquiry,the evolutionary ecology of the genome. [source] THE FITNESS EFFECT OF MUTATIONS ACROSS ENVIRONMENTS: A SURVEY IN LIGHT OF FITNESS LANDSCAPE MODELSEVOLUTION, Issue 12 2006Guillaume Martin Abstract The fitness effects of mutations on a given genotype are rarely constant across environments to which this genotype is more or less adapted, that is, between more or less stressful conditions. This can have important implications, especially on the evolution of ecological specialization. Stress is thought to increase the variance of mutations' fitness effects, their average, or the number of expressed mutations. Although empirical evidence is available for these three mechanisms, their relative magnitude is poorly understood. In this paper, we propose a simple approach to discriminate between these mechanisms, using a survey of empirical measures of mutation effects in contrasted environments. This survey, across various species and environments, shows that stress mainly increases the variance of mutations effects on fitness, with a much more limited impact on their average effect or on the number of expressed mutations. This pattern is consistent with a simple model in which fitness is a Gaussian function of phenotypes around an environmentally determined optimum. These results suggest that a simple, mathematically tractable landscape model may not be quantitatively as unrealistic as previously suggested. They also suggest that mutation parameter estimates may be strongly biased when measured in stressful environments. [source] THE CHANGING STRUCTURE OF THE CENTRAL PLACE SYSTEM IN TRØNDELAG, NORWAY, OVER THE PAST 40 YEARS , VIEWED IN THE LIGHT OF OLD AND RECENT THEORIES AND TRENDSGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2007Britt Dale ABSTRACT. The IGU Symposium on Urban Geography in Lund in 1960 was a path-breaking event towards new nomothetic thinking within the discipline. In nearly half of the papers, the state of the art in central place research was presented and debated. The symposium was the main source of inspiration for a study of the central place system in Midt-Norge in the 1960s, a research project that has been followed up in stages over a 40-year period. The result is a unique collection of data, covering all central places in the region and the location of approximately 200 service functions of different categories in the 1960s, 1980s and c. 2000. Despite the profound changes that have taken place on the part of the consumer, as well as the supplier, the main structure of the central place hierarchy has been surprisingly stable. However, when looking at the growth and decline of each of the different service functions, considerable dynamics have been found. There are tendencies of centralization/concentration as well as decentralization/dispersion. Furthermore, the functional division of labour by vertical steps and tiers in the 1960s has been supplemented by horizontal specialization between places, and also in the lower levels of the central place hierarchy. In this paper, we present and discuss some of the main changes that have taken place in the system in the light of older and newer theories and trends. [source] Lymphotoxin and LIGHT signaling pathways and target genesIMMUNOLOGICAL REVIEWS, Issue 1 2004Kirsten Schneider Summary:, Lymphotoxins (LT, and LT,), LIGHT [homologous to LT, inducible expression, competes with herpes simplex virus (HSV) glycoprotein D for HSV entry mediator (HVEM), a receptor expressed on T lymphocytes], tumor necrosis factor (TNF), and their specific receptors LT,R, HVEM, and TNF receptor 1 (TNFR1) and TNFR2, form the immediate family of the larger TNF superfamily. These cytokines establish a critical communication system required for the development of secondary lymphoid tissues; however, knowledge of the target genes activated by these signaling pathways is limited. Target genes regulated by the LT,,-LT,R pathway include the tissue-organizing chemokines, CXCL13, CCL19, and CCL21, which establish cytokine circuits that regulate LT expression on lymphocytes, leading to organized lymphoid tissue. Infectious disease models have revealed that LT,, pathways are also important for innate and adaptive immune responses involved in host defense. Here, regulation of interferon-, by LT,R and TNFR signaling may play a crucial role in certain viral infections. Regulation of autoimmune regulator in the thymus via LT,R implicates LT/LIGHT involvement in central tolerance. Dysregulated expression of LIGHT overrides peripheral tolerance leading to T-cell-driven autoimmune disease. Blockade of TNF/LT/LIGHT pathways as an intervention in controlling autoimmune diseases is attractive, but such therapy may have risks. Thus, identifying and understanding the target genes may offer an opportunity to fine-tune inhibitory interventions. [source] LIGHTing up dendritic cell activation: Immune regulation and viral exploitationJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2005Gabriele Pollara The maturation state of dendritic cells (DC) is regulated by a variety of factors. These include ligands expressed by T cells, such as members of the TNF superfamily. Recent studies have highlighted the role of one such molecule, LIGHT, as a positive regulator of DC biology, promoting the maturation of these cells through the activation of NF-,B pathways. In addition, HSV-1 envelope glycoproteins can also bind the LIGHT receptor, herpes virus entry mediator (HVEM), and activate similar downstream signalling pathways in DC. The consequence of this host-viral interaction may be a novel pathway of viral immune evasion. © 2005 Wiley-Liss, Inc. [source] LIPID OXIDATION OF FISH LIVER OIL AS AFFECTED BY LIGHT, ANTIOXIDANTS AND TEMPERATUREJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2004WEIGUO SANG Crude and refined Mackerel liver oil with or without antioxidants were stored in artificial light or in darkness to assess the effects of photo-oxidative stress on the stability of oils and the antioxidant activity of butylated hydroxy-anisole (BHA) and tert-butylhydroquinone (TBHQ) on those oils. Changes in peroxide value (PV) and thiobarbituric acid value (TBA) were monitored over 18 days at 5C and 40C. The results showed that visible light exposure played the most critical role in the acceleration of fish liver oil oxidation. The addition of antioxidants showed a significant effect in retarding oxidation with TBHQ more effective than BHA. The oxidation rate of the oils decreased in the following order: control with light > control + BHA with light > control without light > control + TBHQ with light > control + BHA without light > control + TBHQ without light. Higher PV and TBA values were observed in refined oils versus crude oils. Increasing storage temperature accelerated the oxidation of only refined oils in light. [source] THE ANTARCTIC PSYCHROPHILE, CHLAMYDOMONAS RAUDENSIS ETTL (UWO241) (CHLOROPHYCEAE, CHLOROPHYTA), EXHIBITS A LIMITED CAPACITY TO PHOTOACCLIMATE TO RED LIGHT,JOURNAL OF PHYCOLOGY, Issue 4 2005Rachael M. Morgan-Kiss The psychrophilic Antarctic alga, Chlamydomonas raudensis Ettl (UWO241), grows under an extreme environment of low temperature and low irradiance of a limited spectral quality (blue-green). We investigated the ability of C. raudensis to acclimate to long-term imbalances in excitation caused by light quality through adjustments in photosystem stoichiometry. Log-phase cultures of C. raudensis and C. reinhardtii grown under white light were shifted to either blue or red light for 12 h. Previously, we reported that C. raudensis lacks the ability to redistribute light energy via the short-term mechanism of state transitions. However, similar to the model of mesophilic alga, C. reinhardtii, the psychrophile retained the capacity for long-term adjustment in energy distribution between PSI and PSII by modulating the levels of PSI reaction center polypeptides, PsaA/PsaB, with minimal changes in the content of the PSII polypeptide, D1, in response to changes in light quality. The functional consequences of the modulation in PSI/PSII stoichiometry in the psychrophile were distinct from those observed in C. reinhardtii. Exposure of C. raudensis to red light caused 1) an inhibition of growth and photosynthetic rates, 2) an increased reduction state of the intersystem plastoquinone pool with concomitant increases in nonphotochemical quenching, 3) an uncoupling of the major light-harvesting complex from the PSII core, and 4) differential thylakoid protein phosphorylation profiles compared with C. reinhardtii. We conclude that the characteristic low levels of PSI relative to PSII set the limit in the capacity of C. raudensis to photoacclimate to an environment enriched in red light. [source] CYANOBACTERIAL ACCLIMATION TO RAPIDLY FLUCTUATING LIGHT IS CONSTRAINED BY INORGANIC CARBON STATUS,JOURNAL OF PHYCOLOGY, Issue 4 2005Tyler D. B. MacKenzie Acclimation to rapidly fluctuating light, simulating shallow aquatic habitats, is altered depending on inorganic carbon (Ci) availability. Under steady light of 50 ,mol photons·m,2·s,1, the growth rate of Synechococcus elongatus PCC7942 was similar in cells grown in high Ci (4 mM) and low Ci (0.02 mM), with induced carbon concentrating mechanisms compensating for low Ci. Growth under fluctuating light of a 1-s period averaging 50 ,mol photons·m,2·s,1 caused a drop in growth rate of 28%±6% in high Ci cells and 38%±8% in low Ci cells. In high Ci cells under fluctuating light, the PSI/PSII ratio increased, the PSII absorption cross-section decreased, and the PSII turnover rate increased in a pattern similar to high-light acclimation. In low Ci cells under fluctuating light, the PSI/PSII ratio decreased, the PSII absorption cross-section decreased, and the PSII turnover remained slow. Electron transport rate was similar in high and low Ci cells but in both was lower under fluctuating than under steady light. After acclimation to a 1-s period fluctuating light, electron transport rate decreased under steady or long-period fluctuating light. We hypothesize that high Ci cells acclimated to exploit the bright phases of the fluctuating light, whereas low Ci cells enlarged their PSII pool to integrate the fluctuating light and dampen the variation of the electron flux into a rate-restricted Ci pool. Light response curves measured under steady light, widely used to predict photosynthetic rates, do not properly predict photosynthetic rates achieved under fluctuating light, and exploitation of fluctuating light is altered by Ci status. [source] UV-A/BLUE LIGHT,INDUCED REACTIVATION OF SPORE GERMINATION IN UV-B IRRADIATED ULVA PERTUSA (CHLOROPHYTA),JOURNAL OF PHYCOLOGY, Issue 2 2004Taejun Han Recent reduction in the ozone shield due to manufactured chlorofluorocarbons raised considerable interest in the ecological and physiological consequences of UV-B radiation (,=280,315 nm) in macroalgae. However, early life stages of macroalgae have received little attention in regard to their UV-B sensitivity and UV-B defensive mechanisms. Germination of UV-B irradiated spores of the intertidal green alga Ulva pertusa Kjellman was significantly lower than in unexposed controls, and the degree of reduction correlated with the UV doses. After exposure to moderate levels of UV-B irradiation, subsequent exposure to visible light caused differential germination in an irradiance- and wavelength-dependent manner. Significantly higher germination was found at higher photon irradiances and in blue light compared with white and red light. The action spectrum for photoreactivation of germination in UV-B irradiated U. pertusa spores shows a major peak at 435 nm with a smaller but significant peak at 385 nm. When exposed to December sunlight, the germination percentage of U. pertusa spores exposed to 1 h of solar radiation reached 100% regardless of the irradiation treatment conditions. After a 2-h exposure to sunlight, however, there was complete inhibition of germination in PAR+UV-A+UV-B in contrast to 100% germination in PAR or PAR+UV-A. In addition to mat-forming characteristics that would act as a selective UV-B filter for settled spores under the parental canopy, light-driven repair of germination after UV-B exposure could explain successful continuation of U. pertusa spore germination in intertidal settings possibly affected by intense solar UV-B radiation. [source] UNCOUPLING OF SILICON COMPARED WITH CARBON AND NITROGEN METABOLISMS AND THE ROLE OF THE CELL CYCLE IN CONTINUOUS CULTURES OF THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE) UNDER LIGHT, NITROGEN, AND PHOSPHORUS CONTROL1JOURNAL OF PHYCOLOGY, Issue 5 2002Pascal Claquin The elemental composition and the cell cycle stages of the marine diatom Thalassiosira pseudonana Hasle and Heimdal were studied in continuous cultures over a range of different light- (E), nitrogen- (N), and phosphorus- (P) limited growth rates. In all growth conditions investigated, the decrease in the growth rate was linked with a higher relative contribution of the G2+M phase. The other phases of the cell cycle, G1 and S, showed different patterns, depending on the type of limitation. All experiments showed a highly significant increase in the amount of biogenic silica per cell and per cell surface with decreasing growth rates. At low growth rates, the G2+M elongation allowed an increase of the silicification of the cells. This pattern could be explained by the major uptake of silicon during the G2+M phase and by the independence of this process on the requirements of the other elements. This was illustrated by the elemental ratios Si/C and Si/N that increased from 2- to 6-fold, depending of the type of limitation, whereas the C/N ratio decreased by 10% (E limitation) or increased by 50% (P limitation). The variations of the ratios clearly demonstrate the uncoupling of the Si metabolism compared with the C and N metabolisms. This uncoupling enabled us to explain that in any of the growth condition investigated, the silicification of the cells increased at low growth rates, whereas carbon and nitrogen cellular content are differently regulated, depending of the growth conditions. [source] ACCUMULATION OF OLEIC ACID IN HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE) UNDER NITROGEN STARVATION OR HIGH LIGHT IS CORRELATED WITH THAT OF ASTAXANTHIN ESTERS1JOURNAL OF PHYCOLOGY, Issue 2 2002Mirash Zhekisheva The chlorophyte Haematococcus pluvialis accumulates large quantities of astaxanthin under stress conditions. Under either nitrogen starvation or high light, the production of each picogram of astaxanthin was accompanied by that of 5 or 3,4 pg of fatty acids, respectively. In both cases, the newly formed fatty acids, consisting mostly of oleic (up to 34% of fatty acids in comparison with 13% in the control), palmitic, and linoleic acids, were deposited mostly in triacylglycerols. Furthermore, the enhanced accumulation of oleic acid was linearily correlated with that of astaxanthin. Astaxanthin, which is mostly monoesterified, is deposited in globules made of triacylglycerols. We suggest that the production of oleic acid-rich triacylglycerols on the one hand and the esterification of astaxanthin on the other hand enable the oil globules to maintain the high content of astaxanthin esters. [source] USING INCIDENT LIGHT TO MAXIMIZE RESOLUTION OF STRUCTURE ON DIATOM VALVES WITH A LIGHT MICROSCOPEJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Siver, P. A. Botany Department, Connecticut College, New London, CT 06320 Because of their abundance in a diverse array of aquatic habitats and chemical conditions, and the fact that their species-specific siliceous outer coverings remain for millennia in sediments, diatoms have become one of the most powerful organismal groups used in the reconstruction of historical environmental conditions. Although SEM is now needed to identify some species, the bulk of the identifications and data collection is still accomplished with a light microscope. In this paper I will demonstrate the use of interference reflection contrast (incident light) for the examination of diatoms that significantly improves the resolution of structural detail. Using incident light one can routinely distinguish between structures close to the theoretical limit of resolution for visible light, and about 70 nm closer together than resolvable with standard transmitted light optics. Examples of how the incident light technique can improve data collection with light microscopy will be given. Most research light microscopes could be easily and inexpensively outfitted to use this technique. [source] EROS AND/AS DESIRE,A THEOLOGICAL AFFIRMATION: PAUL TILLICH READ IN THE LIGHT OF JEAN-LUC MARION'S THE EROTIC PHENOMENONMODERN THEOLOGY, Issue 2 2010JAN-OLAV HENRIKSEN The article interprets Tillich's varied elaborations on different aspects of eros, mainly in his Systematic Theology, by reading them in the light of Jean-Luc Marion's phenomenological description of eros in its various aspects in The Erotic Phenomenon. The erotic in Tillich not only has to do with sex and desire, but also with his commitment to a realistic approach to what it means to be human, to human culture, and to confronting false and estranging interpretations of basic human phenomena. What seems to be missing in Tillich, however, is a more comprehensive treatment of eros/desire that would make possible an understanding of the phenomenological (and consequently existential) fullness of this phenomenon. I suggest that this can be achieved by reading Tillich by way of Marion's phenomenological analysis. This also has the virtue of overcoming the all-too abstract character of Tillich's reasoning without at the same time dismissing Tillich's treatment of eros. I will also draw out some implications for how one might deal with eros and desire in the emerging discussion in present systematic theology. [source] LIGHT, DARKNESS, AND AFRICAN SALVATION: VELÁZQUEZ'S SUPPER AT EMMAUSART HISTORY, Issue 1 2008TANYA J. TIFFANY This study locates Velázquez's Supper at Emmaus (c. 1617/18) within early seventeenth-century debates on the Christian conversion of Seville's African slaves. Through a careful analysis of writings by Sevillian clerics, the essay argues that Velázquez gave pictorial form to discourse on African spiritual ,illumination' and developing theories of skin colour. Treatises by Seville's ecclesiastics also provide crucial insight into the original, elite audience for whom Velázquez surely constructed his African subject. In Supper at Emmaus, Velázquez presented his male beholder with one possession encompassed within another: a female slave in a painting by Seville's most promising young artist. [source] Evidence of epistasis between TNFRSF14 and TNFRSF6B polymorphisms in patients with rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 3 2010Nieves Perdigones Objective Genetic variants located close to 2 genes codifying for members of the tumor necrosis factor receptor superfamily (TNFRSF), TNFRSF14 and TNFRSF6B, have recently been associated with rheumatoid arthritis (RA) and with inflammatory bowel disease susceptibility, respectively. The TNFRSF6B protein has been related to osteoclastic activity, apoptosis inhibition, and modulation of T cell activation and differentiation. Interestingly, peptides encoded by both genes bind a common ligand called LIGHT, which is overexpressed in RA synovium. The aim of this study was to investigate the combined effect of the TNFRSF14 rs6684865 and TNFRSF6B rs4809330 polymorphisms in RA predisposition. Methods TaqMan genotyping of these polymorphisms was conducted in 649 patients with RA and 553 ethnically matched control subjects (first study). To validate the results, an independent replication cohort with 211 patients and 255 control subjects was additionally studied (replication study). Results The frequency of the rs6684865 G allele in the RA subgroup with the rs4809330 GG susceptibility genotype was significantly higher than that in the other patients with RA (74% versus 65%; P = 0.002) or in control subjects (74% versus 67%; P = 0.003). Because no significant differences between the control and patient groups in the first and replication studies were observed, the data were pooled. When compared with control subjects overall, the effect of the rs6684865 G allele in the group with the rs4809330 GG genotype (odds ratio [OR] 1.49) was significantly different from the effect observed in the group carrying the rs4809330 A allele (OR 0.97; P = 0.0015 by Breslow-Day test of homogeneity). Conclusion We have identified and replicated a novel gene,gene interaction between 2 polymorphisms of TNFRSF members in Spanish patients with RA, based on the hypothesis of shared pathogenic pathways in complex diseases. [source] Light up-regulated on B lymphocytes and monocytes in rheumatoid arthritis mediates cellular adhesion and metalloproteinase production by synoviocytesARTHRITIS & RHEUMATISM, Issue 4 2007Young Mo Kang Objective To study the expression of LIGHT (tumor necrosis factor superfamily 14) and herpesvirus entry mediator (HVEM; tumor necrosis factor receptor superfamily 14) in rheumatoid arthritis (RA) and to determine the regulatory role of LIGHT on the effector functions of fibroblast-like synoviocytes (FLS). Methods The expression of LIGHT and HVEM was assessed by immunohistochemical staining of synovial tissue and by flow cytometric analysis of mononuclear cells. The presence of HVEM and lymphotoxin , receptor was measured by reverse transcriptase,polymerase chain reaction and by flow cytometry. The regulation of effector molecules, including matrix metalloproteinases (MMPs) and adhesion molecules, was evaluated. The adhesiveness of FLS was determined by adhesion assay. Results HVEM was detected in most cell types within rheumatoid synovial tissue, while only a few cells were positive for LIGHT. In RA patients, LIGHT expression was significantly up-regulated only in CD20+ B cells and monocytes, whereas the mean fluorescence intensity of HVEM was down-regulated in mononuclear cells. The stimulation of FLS with LIGHT resulted in the production of MMPs and the expression of adhesion molecules, which were efficiently inhibited by dexamethasone. LIGHT-mediated up-regulation of MMPs and intercellular adhesion molecule 1 was blocked by inhibitors of NF-,B and JNK, whereas up-regulation of vascular cell adhesion molecule 1 was blocked by inhibitors of phosphatidylinositol 3-kinase, as well as NF-,B. Conclusion These data suggest that binding of LIGHT with its receptors may play a role in the progression of inflammation within rheumatoid synovium, especially by mediating the interactions between infiltrating inflammatory cells and stromal cells. These findings thus emphasize the relevance of LIGHT as a potential therapeutic target in RA. [source] EPIDEMIOLOGY AND SOCIAL JUSTICE IN LIGHT OF SOCIAL DETERMINANTS OF HEALTH RESEARCHBIOETHICS, Issue 2 2009SRIDHAR VENKATAPURAM ABSTRACT The present article identifies how social determinants of health raise two categories of philosophical problems that also fall within the smaller domain of ethics; one set pertains to the philosophy of epidemiology, and the second set pertains to the philosophy of health and social justice. After reviewing these two categories of ethical concerns, the limited conclusion made is that identifying and responding to social determinants of health requires inter-disciplinary reasoning across epidemiology and philosophy. For the reasoning used in epidemiology to be sound, for its scope and (moral) purpose as a science to be clarified as well as for social justice theory to be relevant and coherent, epidemiology and philosophy need to forge a meaningful exchange of ideas that happens in both directions. [source] WHEN THE LIGHTS GO OUT IN CHESHIRE¶GEOGRAPHICAL REVIEW, Issue 4 2005GEOFFREY L. BUCKLEY ABSTRACT. The purchase and subsequent demolition of Cheshire, Ohio-located in the shadow of the General James M. Gavin Power Plant-has attracted national attention. According to a New York Times report, "the deal , is believed to be the first by a company to dissolve an entire town." In this article we consider historical precedents for the case, explore the thirty-year history of community-plant relations in Cheshire, and recount the series of incidents that ultimately led to the town's sale. We discuss the impact that the town's sale has had on the local community and the larger implications of American Electric Power's actions. [source] QUARTZ-TUNGSTEN-HALOGEN AND LIGHT-EMITTING DIODE CURING LIGHTSJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 3 2006Kraig S. Vandewalle DDS Curing lights are an integral part of the daily practice of restorative dentistry. Quartz-tungsten-halogen (QTH), plasma-arc (PAC), argon laser, and light-emitting diode (LED) curing lights are currently commercially available. The QTH curing light has a long, established history as a workhorse for composite resin polymerization in dental practices and remains the most common type of light in use today. Its relatively broad emission spectrum allows the QTH curing light to predictably initiate polymerization of all known photo-activated resin-based dental materials. However, the principal output from these lamps is infrared energy, with the generation of high heat. Filters are used to reduce the emitted heat energy and provide further restriction of visible light to correlate better with the narrower absorbance spectrum of photo-initiators. The relatively inefficient emission typically requires corded handpieces with noisy fans. PAC lights generate a high voltage pulse that creates hot plasma between two electrodes in a xenon-filled bulb. The irradiance of PAC lights is much higher than the typical QTH curing light, but PAC lights are more expensive and generate very high heat with an inefficient emission spectrum similar to that of QTH bulbs. Light emitted from an argon laser is very different from that emitted from the halogen or PAC lights. The photons produced are coherent and do not diverge; therefore, lasers concentrate more photons of specific frequency into a tiny area. With very little infrared output, unwanted heat is minimized. However, argon lasers are very expensive and inefficient due to a small curing tip. LED curing lights have been introduced to the market with the promise of more efficient polymerization, consistent output over time without degradation, and less heat emission in a quiet, compact, portable device. This review evaluates some of the published research on LED and QTH curing lights. [source] Attention deficit hyperactivity disorder and suicide: a review of possible associationsACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2004A. James Objective:, To review the evidence of a possible association between attention deficit hyperactivity disorder (ADHD) and suicide. Design:, We searched the electronic data bases: Medline, Psych LIT, between 1966 and March 2003 looking for articles on ADHD, attention deficit disorder, hyperactivity and suicide. Results:, An association of ADHD and completed suicide was found, especially for younger males. However, the evidence for any direct or independent link was modest with an overall suicide rate from long-term follow-up studies of ADHD of 0.63,0.78%. The estimated relative risk ratio, compared with US national suicide rates (males 5,24 years) is 2.91 (95% confidence interval 1.47,5.7, ,2 = 9.3, d.f. = 1, P = 0.002). ADHD appears to increase the risk of suicide in males via increasing severity of comorbid conditions, particularly conduct disorder (CD) and depression. Conclusion:, Identification of those at risk, particularly males with comorbid ADHD, depression and CD, may represent a useful clinical means of reducing completed suicide. [source] Latest news and product developmentsPRESCRIBER, Issue 2 2008Article first published online: 11 FEB 200 NICE should evaluate all new medicines NICE should determine the cost effectiveness of all new medicines, the Health Select Committee has concluded in its second review of the Institute. The review, prompted by criticisms from patients, health professionals and the pharmaceutical industry, found that NICE is doing ,a vital job in difficult circumstances'. The Committee called for the costs to carers and society to be included in cost effectiveness estimates (this is currently prohibited) and for cost per QALY thresholds to be aligned with NHS affordability. NICE should publish brief appraisals at the time of a product launch , these could be used to negotiate prices. GPs responsible for unlicensed co-proxamol GPs who prescribe co-proxamol are now responsible for the consequences, the MHRA warns. The Agency agrees that the drug may be needed by ,a small group of patients who are likely to find it very difficult to change from co-proxamol or where alternatives appear not to be effective or suitable'. Following the withdrawal of product licences, stock that is currently in the supply chain may be dispensed but no new stock should be released by suppliers. The Drug Tariff price of co-proxamol has now increased from £2.79 to £20.36 per 100 tablets. Vitamin D deficiency on the increase Pregnant and breastfeeding women may need vitamin D supplements, the Department of Health has warned, and GPs are seeing increasing numbers of patients with vitamin D deficiency. Endogenous synthesis may be low in some ethnic groups and dark-skinned people, and north of Birmingham there is no light of the appropriate wavelength for the synthesis of vitamin D during the winter. The Department says free vitamin supplements are available for eligible patients through its Healthy Start Scheme (www.healthystart.nhs.uk) and may also be supplied at low cost by some PCTs. Innovation and good practice recognised Innovative practice and better outcomes for patients have been recognised through awards from the NHS Alliance and Improvement Foundation presented by the Secretary of State for Health, Rt Hon Alan Johnson, at the annual NHS Alliance conference held in Manchester. The Mountwood Surgery in Northwood, Middlesex, won the CHD QOF GP Practice Award sponsored by Schering Plough for their outstanding multidisciplinary approach to tackling CHD. In addition to having a highly organised in-house cardiology team, they have produced an interactive, patient-empowering booklet for CHD. Mountwood Surgery achieved blood pressure targets of 96.79 per cent in their CHD patients. North Tees PCT wins the CHD QOF PCO Award, also sponsored by Schering Plough, for their support and encouragement to GP practices to ,own' CHD care. They provide timely feedback of performance data using funnel plots and regular communication by the CHD LIT and Cardiac Network. Even though North Tees PCT has a high CHD prevalence, 4.2 per cent vs 3.6 per cent nationally, across the 27 practices 85 per cent of patients achieved cholesterol targets and 91 per cent reached the QOF blood pressure target. The St Benedict's Hospice Day Centre Project (for the Sunderland Teaching Primary Care Trust) won the Guy Rotherham Award for its excellent multidisciplinary team improvement of the palliative care provided. This team demonstrated a thorough understanding of the use of quality improvement methods to improve patient care, and carefully measured the individual improvements they made. Through the use of a referral ,decision tree', nonattenders were reduced by 300 per cent and average waiting times halved. The Extended Primary Care (EPC) Gynaecology Service (for the Practice Based Commissioning Consortium South Manchester Hub) was highly commended for its development of an effective and innovative service offering gynaecological treatment managed within a primary care setting, allowing patients improved access closer to home. The Salford Perinatal Mental Health Project was also highly commended for effectively challenging the high levels of maternal suicides. The awards were also supported by Prescriber, the British Cardiac Patients Association and the British Cardiac Society. Anastrozole superior to tamoxifen in long term A new analysis of the ATAC trial (Lancet Oncology 2008;9:45-53) shows that the advantages of the aromatase inhibitor anastrozole (Arimidex) over tamoxifen as adjuvant therapy for breast cancer persist for at least four years after the end of treatment. After primary treatment with surgery, chemotherapy or radiotherapy, postmenopausal women with localised invasive breast cancer were randomised to five years' treatment with anastrozole or tamoxifen. Among 5216 women who were hormone-receptor positive, anastrozole increased disease-free survival by 15 per cent after 100 months. Time to recurrence and distant recurrence were also increased, though overall survival was similar; the absolute difference in time to recurrence was greater at nine years (4.8 per cent) than at five years (2.8 per cent). Joint symptoms and fractures were more frequent with anastrozole during treatment but not thereafter. Use a steroid with a LABA , MHRA reminder The MHRA has reminded clinicians that patients treated with an inhaled long-acting beta-agonist (LABA) should also use an inhaled steroid. In the latest edition of Drug Safety Update (2008;1:No.6), the Agency reviews the implications of the SMART study (Chest 2006;129:15-26), which reported an increased risk of respiratory- and asthma-related deaths among patients using salmeterol (Serevent). This is contradicted by epidemiological data suggesting that asthma-related admissions have declined since LABAs were introduced. Randomised trials also do not support such a risk, probably because inhaled steroids are used more consistently in trial settings. The latest Update notes that product licences for carisoprodol (Carisoma) have been suspended due to concerns about the risk of abuse and psychomotor effects. It also includes a comprehensive summary of drug interactions with statins, a warning that methylene blue should not be prescribed for a patient taking a drug with serotonergic activity, and a reminder that only oral formulations of desmopressin are now licensed for primary nocturnal enuresis. This issue of Update is available at www.mhra.gov.uk. Copyright © 2008 Wiley Interface Ltd [source] ORIGINAL ARTICLE: Cell-Surface CD200 May Predict Efficacy of Paternal Mononuclear Leukocyte Immunotherapy in Treatment of Human Recurrent Pregnancy LossAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009David A. Clark Problem, The allogeneic leukocytes in transfused blood can modulate the recipient's immune system so as to induce TGF-,-producing suppressor cells, and the cell-surface CD200 tolerance-signaling molecule on mononuclear dendritic cells is required for this effect. A subset of couples with unexplained recurrent pregnancy loss appears to benefit from transfusion of allogeneic paternal blood leukocytes (LIT), and considerable effort has been devoted to characterizing those who may benefit. Some data has been accumulated for LIT as sole therapy in patients with classical spontaneous abortions with respect to dose,response, duration of protection, need for boosting, excluding patients with autoimmunity, and inefficacy of paternal mononuclear cells stored at 4°C overnight before use which causes loss of cell-surface CD200. Recent data emphasize an important role of expression of the CD200 tolerance-signaling molecule on cells used to prevent abortions both in mice and humans. Method of study, An observational study of outcome as a function of the number of CD200+ paternal mononuclear cells was performed. Fourteen patients constituted the pilot group. Patients with autoimmunity who had failed inspite of treatment with IVIG + Heparin + Aspirin ± Prednisone were allowed to have paternal mononuclear cells added to their therapy. CD200 on purified paternal blood mononuclear cells was measured by flow cytometry. Results, The number of CD200+ cells administered was significantly greater in women achieving pregnancy (39.2 × 106 versus 20.8 × 106, P < 0.025) and in those who achieved a live birth (50.2 × 106 versus 20.8 × 106, P < 0.005) compared to those who did not achieve pregnancy, and % of paternal cells that were CD200+ was greater (11,12.5% versus 5.6%, P < 0.01). Amongst those achieving pregnancy which failed, the CD200+ cell dose was not significantly different from the non-pregnant group (30.5 × 106 versus 20.8 × 106). Conclusion, The number of CD200+ paternal mononuclear leukocytes may be an important determinant of subsequent reproductive outcome in a subset of patients. A lower % CD200+ cell number may also reflect hitherto unappreciated paternal factors bearing on reproductive success. It is feasible to recruit women to enter observational studies and to obtain useful data as a foundation for further studies. More complete patient characterization in a larger study is needed. [source] Transfusion-Related Risks of Intradermal Allogeneic Lymphocyte Immunotherapy: Single Cases in a Large Cohort and Review of the LiteratureAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2006Christiane Kling Problem, Lymphocyte immunotherapy (LIT) is applied in infertility treatment. Moreover, it has been suggested for prevention of rhesus D-hemolytic disease and as a vaccine for reduction of human immunodeficiency virus-1 susceptibility. Although transfusion-related problems have been rarely reported they were a matter of debate. Here we discuss extensive single-center experience with intradermal LIT for implantation failure and recurrent miscarriages. Method of study, Retrospective 2- to 3-year follow-up of in vitro fertilization couples treated during 1996,2002 (feedback 2848/3041 = 93%), registering 930 deliveries. Prospective survey for acute reactions for 2000,2003 (feedback 2687/3246 = 83%). Review of the literature. Results, Infections of the patient and transplant rejection later in life are minor residual risks. Post-transfusion purpura was suspected once but not verified. Anaphylaxis or malignancy were not promoted. Fetal/newborn alloimmune disease (severe hemolytic disease, thrombocytopenia, neutropenia) were not observed. Conclusion, Based on microbiological, immunological, and hematological testing the risks of intradermal LIT are low. [source] Crafting Museum Experiences in Light of Research on Learning: Implications of the National Research Council's Report on Informal Science EducationCURATOR THE MUSEUM JOURNAL, Issue 2 2010Andrew Shouse The report is a synthesis of some 2,000 studies and evaluations of learning in non-school settings such as museums. Here we focus on three specific topics discussed in the full report, which we see as particularly important for museum professionals. These are: a framework for developing and studying science learning experiences; cultural diversity as an integral resource for learning; and assessment of learning. Many museums include "learning" among their goals and many researchers concern themselves with how museums and other settings can be organized to support learning. Yet this wealth of research is rarely brought into focus and offered as guidance to the museum community. [source] Chronotherapeutics for Affective Disorders: A Clinician's Manual for Light and Wake TherapyACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2010Klaus Martiny No abstract is available for this article. [source] Split-Face Treatment of Facial Dyschromia: Pulsed Dye Laser with a Compression Handpiece versus Intense Pulsed LightDERMATOLOGIC SURGERY, Issue 5 2008KENNETH J. GALECKAS MD BACKGROUND Many visible light lasers and intense pulsed light (IPL) devices are available to treat photodamaged skin. OBJECTIVES The objective was to perform a multiple-treatment split-face comparison evaluating a pulsed dye laser (PDL) with a compression handpiece versus IPL for photorejuvenation. METHODS Ten subjects were treated three times at 3- to 4-week intervals. One side of the face was treated with the PDL with compression handpiece, and the other with IPL. One month after final treatment, blinded evaluation assessed for improvements in dyschromias and texture. Patients provided self-assessment of improvement in dyschromias and texture. Time to complete final treatments and pain during all treatments were recorded for each device. RESULTS Improvement of the PDL was (mean) 86.5, 65, 85, 38, and 40% for dark lentigines, light lentigines, vessels <0.6 mm, vessels >0.6 mm, and texture, respectively, versus 82, 62.5, 78.5, 32.5, and 32%, respectively, for the IPL side. Patient-evaluated difference in improvement for vascular lesions significantly favored the PDL (p=.011). Mean third treatment times were 7.7 minutes for PDL versus 4.6 minutes for the IPL (p=.005). Mean pain ratings were 5.8 for the PDL and 3.1 for the IPL (p=.007). Purpura-free procedures depended on proper technical use of the compression handpiece when treating lentigines with the PDL. CONCLUSIONS The PDL with compression handpiece and IPL are highly effective for photorejuvenation. [source] Treatment of Inflammatory Facial Acne Vulgaris with Intense Pulsed Light and Short Contact of Topical 5-Aminolevulinic Acid: A Pilot StudyDERMATOLOGIC SURGERY, Issue 8 2006JINDA ROJANAMATIN MD BACKGROUND Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) and red light (550,700 nm) has been introduced for effective treatment of facial acne. Untoward side effects are common, however. OBJECTIVE To evaluate the efficacy and safety of the short contact of topical ALA and intense pulsed light (IPL) in treatment of inflammatory facial acne. METHODS Fourteen patients with inflammatory facial acne were treated with IPL on the left side and combination of IPL and topical ALA on the right side at 3- to 4-week intervals for three sessions. Clinical photographs and lesion counts were obtained for evaluation. RESULTS All patients revealed a reduction in number of acne lesions on both sides. On the ALA-pretreated side, lesion counts decreased 87.7% at 12 weeks after the last treatment (p<.01). Meanwhile, lesion counts on the nonpretreated side decreased 66.8% (p<.01). In addition, a number of lesion counts on the ALA-pretreated side decreased. Mild edema and minimal crust developed on the combined-treatment side. CONCLUSION Short contact of topical ALA and IPL or IPL alone showed some beneficial effect in treatment of inflammatory facial acne; however, degree of improvement was better and remained longer with the combined regimen. Side effects were mild and reversible. [source] Treatment of Idiopathic Cutaneous Hyperchromia of the Orbital Region (ICHOR) with Intense Pulsed LightDERMATOLOGIC SURGERY, Issue 6 2006NATALIA CYMROT CYMBALISTA MD BACKGROUND Idiopathic cutaneous hyperchromia of the orbital region (ICHOR) does not have a clear etiopathogenesis. Genetic factors, increased melanin, prominent vasculature, and eyelid skin slackness seem to be involved. OBJECTIVE To evaluate individuals with ICHOR clinically and histologically, before and after treatment with high-energy pulsed light (HEPL), considering epidermal and dermal melanin, in order to evaluate HEPL efficacy in clearing away ICHOR, and 1 month and 1 year later to check whether improvement was maintained. METHODS Twelve individuals with ICHOR underwent clinical and histological evaluation before and after HEPL application, with photographic comparison. They underwent one to four HEPL sessions on the lower eyelid at approximately 30-day intervals. Melanin quantification by area, before and after treatment was performed by digital image morphometry. RESULTS Eyelid skin was significantly lightened (p=.24), and was maintained 1 year later with no ICHOR reincidence. All individuals (100%) showed postinflammatory hyperchromia (average 6-month duration), while 58.33% presented hypochromia (7-month duration). There was significantly decreased epidermal and dermal melanin after treatment. CONCLUSION HEPL was shown to be useful in clearing up ICHOR. This was maintained after 1 year. Epidermal and dermal histopathology showed decreased melanin following treatment. Longer follow-up is needed to evaluate possible later recurrence of ICHOR. [source] Intense Pulsed Light for the Treatment of Refractory Melasma in Asian PersonsDERMATOLOGIC SURGERY, Issue 9 2004Chia-Chen Wang MD Background. Patients with dermal or mixed-type melasmas are often refractory to various treatments. Intense pulsed light has been used to treat melanocytic lesions with promising results. Objective. The purpose of this study was to clarify the effectiveness of intense pulsed light for refractory melasma in Asian persons. Methods. Seventeen patients were treated with intense pulsed light, during four sessions at 4-week intervals. The patients were also given 4% hydroquinone cream and broad-spectrum sunscreens to prevent and treat postinflammatory hyperpigmentation. Sixteen patients in the control group were treated with hydroquinone cream and sunscreens. The treatment efficacy was evaluated using reflectance spectrophotometer and patient satisfaction questionnaire. Results. Patients in the intense pulsed light group achieved an average of 39.8% improvement in relative melanin index, compared to 11.6% improvement in the control group (p<0.05) at Week 16. Six (35%) patients in the intense pulsed light group had more than 50% improvement, compared to two (14%) patients in the control group. Two patients in the intense pulsed light group, however, experienced transient postinflammatory hyperpigmentation, and partial repigmentation was noted 24 weeks after the last treatment session. Conclusion. Intense pulsed light is a safe and effective treatment for refractory melasma in Asian persons, with minimal side effects. Further treatment sessions are required for maintenance therapy. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||