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Radioactive Isotopes (radioactive + isotope)
Selected AbstractsSurvival in patients with papillary thyroid cancer is not affected by the use of radioactive isotopeJOURNAL OF SURGICAL ONCOLOGY, Issue 1 2007Yale D. Podnos MD Abstract Introduction Papillary cancer is the most common neoplasm of the thyroid. The mainstay of treatment is thyroidectomy, but most patients are additionally treated with radioactive iodine (RAI). Its utility is controversial. This study seeks to determine whether RAI use affects patient outcome and to identify specific cohorts of patients that benefit from its use. Methods The Surveillance, Epidemiology, and End Results (SEER) database is a large-scale sample of approximately 14% of the US population. It was used to identify patients with papillary carcinoma of the thyroid. Statistical analyses were used to compare prognostic factors such as lymph node status, age, tumor size, and treatment with RAI. Results A total of 14,545 patients were identified in SEER as having papillary cancer of the thyroid. Multivariate analysis showed significantly worse outcome in patients with age>45 years, tumor size >2 cm, lymph node disease, and distant metastases. Multivariate analysis failed to show RAI significantly affecting mortality. Survival between those not treated with RAI was similar to those whose treatment included it (P,=,0.9176). Subgroup analysis identified patients older than 45 years with primary tumors >2 cm and disease in the lymph nodes with distant metastatic disease as the only group positively affected by RAI. Conclusions Despite its widespread use in the treatment of well-differentiated papillary cancer of the thyroid, RAI only affects a survival advantage in older patients with large primary tumors involving the lymph nodes and with distant spread. Treating other patient groups is costly and offers no improvement in outcome. J. Surg. Oncol. 2007; 96:3,7. © 2007 Wiley-Liss, Inc. [source] The ,Malbouffe' Saga La Saga de la ,Malbouffe' Die Saga von ,Malbouffe"EUROCHOICES, Issue 1 2007Alain Rérat summary The ,Malbouffe' Saga After the end of the Second World War, a marked increase in animal and plant production was observed in France, little by little considered by consumers to be obtained at the expense of product quality. The pejorative term ,malbouffe' soon emerged, in connection not only with the hygiene of food, but also with its organoleptic and technological characteristics. This article focuses on food safety in France, with special attention paid to the incidence of toxi-infections and food contaminations of biological and chemical origin. The Mad Cow outbreak is reviewed, along with its consequences for human health in the form of new variant Creutzfeldt-Jakob's disease. It is emphasized that food-related human mortality , almost exclusively due to biological contaminations , represented only 647 cases in 1995, i.e., 0.12 per cent of the overall mortality rate. The main contaminants were Salmonella, whose number is steadily decreasing, and Campylobacter, but parasite and phycotoxic risks are increasing. Mortality due to chemical contaminants is very low i.e., 10 cases or 0.002 per cent of overall mortality These contaminants, either accidental (dioxin, hydrocarbons, radioactive isotopes) or unavoidable (residues from phytochemicals, fertilisers) may be at the source of acute or chronic intoxications with sometimes unknown consequences. Nevertheless, food safety in France does not merit the spiteful term ,malbouffe'. Nach dem Ende des Zweiten Weltkriegs war in Frankreich im Bereich der Tier- und Pflanzenproduktion ein deutlicher Zuwachs zu beobachten, welcher in den Augen der Verbraucher zunehmend auf Kosten der Produktqualität erreicht wurde. Der abwertende Begriff ,Malbouffe" (in etwa ,schlechtes Essen") entstand bald darauf nicht nur im Hinblick auf die Nahrungsmittelhygiene, sondern auch in Bezug auf die organoleptischen und technologischen Eigenschaften der Nahrungsmittel. Dieser Beitrag konzentriert sich auf die Nahrungsmittelsicherheit in Frankreich unter besonderer Berücksichtigung der aufgetretenen Infektionen durch Giftstoffe und der Kontamination von Nahrungsmitteln biologischen und chemischen Ursprungs. Der BSE-Ausbruch und dessen Auswirkungen auf die Gesundheit des Menschen in Form von einer neuen Variante der Creutzfeldt-Jakob-Krankheit werden noch einmal betrachtet. Es wird hervor gehoben, dass die nahrungsmittelbedingte Sterblichkeit bei Menschen, die nahezu ausschließlich auf biologische Kontaminationen zurückzuführen ist, 1995 bei nur 647 Fällen lag, d.h. bei 0,12 Prozent der gesamten Sterblichkeitsrate. Die Nahrungsmittel wurden hauptsächlich durch Salmonellen (die Anzahl dieser Fälle nimmt kontinuierlich ab) und Campylobacter kontaminiert, die parasitären und phykotoxischen Risiken nehmen jedoch zu. Die auf chemische Kontaminationen zurückzuführende Sterblichkeit ist sehr gering und macht zehn Fälle oder 0,002 Prozent der gesamten Sterblichkeitsrate aus. Bei diesen Kontaminationen, die entweder zufällig herbei geführt werden (durch Dioxin, Kohlenwasserstoff, radioaktive Isotope) oder unvermeidbar sind (durch Rückstände pfl anzenchemischer Substanzen, Düngemittel), könnte es sich um die Ursache für akute oder chronische Vergiftungen handeln, welche zum Teil unbekannte Konsequenzen nach sich ziehen. Dennoch hat die Nahrungsmittelsicherheit in Frankreich den verächtlichen Begriff ,Malbouffe" nicht verdient. Après la fi n de la deuxième guerre mondiale, l'agriculture française a connu une augmentation spectaculaire des rendements des productions animale et végétale, rapidement accusée d'avoir été obtenue aux dépens de la qualité des produits consommés. Ainsi est apparue le terme barbare de «malbouffe», lié dans l'esprit des consommateurs, non seulement aux qualités hygiéniques de l'alimentation, mais également à ses caractéristiques sensorielles, voire technologiques. Ce rapport se focalise uniquement sur la salubrité alimentaire en France, soulignant, en particulier, l'évolution de l'incidence des toxi-infections et des contaminations alimentaires d'origine biologique et chimique. Après avoir rappelé l'épizootie de la vache folle (1000 cas en France depuis 1996 et actuellement en cours d'extinction) et de ses conséquences sur la santé humaine (nouvelle variante de la maladie de Creutzfeldt-Jakob) limitées actuellement à 13 cas mortels dans notre pays, ce rapport précise que la mortalité humaine liée à l'alimentation , presque totalement due à des contaminations biologiques - ne représentait en 1995 que 647 cas, i.e. 0.12% de la mortalité générale. Pour l'essentiel, ces contaminants sont des salmonelles, en baisse constante, et des campylobacter, mais on peut craindre la progression des risques parasitaires et phycotoxiques, encore réduits actuellement. La mortalité liée aux contaminants chimiques est très faible (10 cas, i.e. 0.002% de la mortalité générale); mais ces contaminants -qu'ils soient accidentels (dioxine, hydrocarbures, isotopes radio-actifs,) ou inévitables (résidus de phytosanitaires, d'engrais,)- peuvent être à l'origine de crises aiguës ou d'intoxications chroniques dont on ne connaît pas toujours les implications. Néanmoins, dans l'ensemble, la salubrité alimentaire en France ne mérite nullement la connotation malveillante du terme «malbouffe». [source] Access to Any Site-Directed Isotopomer of Methionine, Selenomethionine, Cysteine, and Selenocysteine , Use of Simple, Efficient Modular Synthetic Reaction Schemes for Isotope IncorporationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004Arjan H. G. Siebum Abstract Simple modular reaction schemes that allow access to any isotopomer of protected serine and homoserine have been worked out. These systems could be simply converted into cysteine, selenocysteine, homocysteine, homoselenocysteine, the essential amino acid methionine, and selenomethionine by Mitsunobu chemistry. These sulfur- and selenium-containing amino acids fulfil many essential roles in the living organism. In addition, homoserine could be converted in a few steps into optically active L -vinylglycine. As well as the stable isotopes 13C, 15N, 17O, and 18O, the radioactive isotopes of sulfur, selenium and carbon can also be easily introduced in a site-directed fashion. In view of the wide scope of the Mitsunobu reaction, we feel that many more important systems with the carbon skeleton of serine and homoserine should be preparable through this basic chemistry in any site-directed isotopically labeled form. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Building a Compact, Low-Cost, and Portable Peristaltic Sampling PumpGROUND WATER, Issue 6 2007William W. Woessner Hydrogeologic research often involves obtaining water quality samples in field settings without vehicle access. Such conditions often require the use of a sampling pump. Researchers at The University of Montana have been using a handheld peristaltic pump powered by a rechargeable variable-speed drill. This Montana Drill Pump (MDP) is highly portable and can be inexpensively built for about $225 to $295 (US). Over the last two decades, the pump has been used to sample and filter (as appropriate) surface water and ground water for analyses of general inorganic and organic chemistry, stable and radioactive isotopes, pathogens, and trace pharmaceuticals and to develop small-diameter wells and sample suction lysimeters. The MDP provides researchers and educators with an economical tool to pump water in classrooms, laboratories, and field settings. [source] Competition for attachment of aquaculture candidate probiotic and pathogenic bacteria on fish intestinal mucusJOURNAL OF FISH DISEASES, Issue 6 2004N G Vine Abstract Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1,AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment. Only AP5 caused lower attachment success of V. alginolyticus when added before the pathogen. When AP5 was added first, the average attachment change was 41% compared with 72% when added after V. alginolyticus, suggesting that the probiotic is displaced but that enhanced attachment of the pathogen does not occur. Conversely, when V. alginolyticus was added first, followed by AP5, attachment change was 37% while AP5 had 92% attachment change when added second. This implies that the pathogen was displaced by the candidate probiotic and therefore it appeared that, based on the ability of probiont AP5 to attach to mucus, the growth of the pathogen in the digestive tract might be suppressed by the candidate probiont's presence. [source] Basic Rules of Dosimetry in Endovascular BrachytherapyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2000PHILIPPE A. COUCKE M.D. Endovascular brachytherapy after percutaneous coronary intervention (PCI), is becoming a standard approach for the treatment and prevention of restenosis. A variety of technical approaches are currently available to deliver ionizing irradiation to the vascular target. Basically two kinds of radioactive isotopes are available that emit gamma radiation (photons) or beta radiation (electrons). The pitfalls and solutions for the optimization of dosimetry are discussed. As might be expected, the inhomogeneous dose distribution across the target volume results in recurrence by underdosage or in complications because of overdosage. Moreover, uniformization of the target definition and reporting of the dose distribution in endovascular brachytherapy is a prerequisite for comparison between the results of the various clinical trials and is absolutely necessary to improve the therapeutic efficacy of this new approach in the prevention of restenosis after coronary angioplasty with or without stenting. [source] Synthesis of deuterium, tritium, and carbon-14 labeled BIRB 796, a p38 MAP kinase inhibitorJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 12 2004Bachir Latli Abstract 1-(5- tert -Butyl-2- p -tolyl-2H-pyrazol-3-yl)-3-[4-(2-morpholin-4-yl-ethoxy)naphthalen-1-yl]urea (BIRB 796), currently in clinical trials for the treatment of inflammatory diseases, is a potent inhibitor of p38 MAP kinase. Labeled BIRB 796 with stable and radioactive isotopes was required for metabolism, distribution, and absorption studies. We first report the synthesis of carbon-14 labeled BIRB 796 with a specific activity of 2 GBq/mmol (54.2 mCi/mmol), using [14C]-phosgene under modified Schotten,Baumann conditions; second the preparation of tritium-labeled BIRB 796 with a specific activity of 659 GBq/mmol (17.81 Ci/mmol) by reductive dehalogenation of iodo-BIRB 796 with tritium gas; and finally, the synthesis of 2H8 -BIRB 796 using morpholine-2,2,3,3,5,5,6,6- 2H8 with isotopic enrichment of 98.9 at% 2H. Copyright © 2004 John Wiley & Sons, Ltd. [source] SEDIMENTARY IMPRINT OF MICROCYSTIS AERUGINOSA (CYANOBACTERIA) BLOOMS IN GRANGENT RESERVOIR (LOIRE, FRANCE),JOURNAL OF PHYCOLOGY, Issue 3 2007Delphine Latour Analysis of a sediment core taken from the Grangent reservoir in 2004 showed the presence of high concentrations of Microcystis aeruginosa Kütz. colonies at the sediment surface (250 colonies,·,mL sediment,1) and also at depths of 25,35 cm (2300 colonies·mL sediment,1) and 70 cm (600 colonies,·,mL sediment,1). Measurements of radioactive isotopes (7Be, 137Cs, and 241Am) along with photographic analysis of the core were used to date the deep layers: the layer located at ,30 cm dates from summer 2003, and that located at ,70 cm from 1990 to 1991. The physiological and morphological conditions of those benthic colonies were compared with those of planktonic colonies using several techniques (environmental scanning electron microscopy [ESEM], TEM, DNA markers, cellular esterases, and toxins). The ESEM observations showed that, as these colonies age, peripheral cells disappear, with no cells remaining in the mucilage of the deepest colonies (70 cm), an indication of the survival thresholds of these organisms. In the benthic phase, the physiological conditions (enzyme activity, cell division, and intracellular toxins) and ultrastructure (particularly the gas vesicles) of the cells surviving in the heart of the colony are comparable to those of the planktonic form, with all the potential needed for growth. Maintaining cellular integrity requires a process that can provide sufficient energy and is expressed in the reduced, but still existing, enzymatic activity that we measured, which is equivalent to a quiescent state. [source] The early history of 32P as a radioactive tracer in biochemical research: A personal memoirBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 3 2005Howard Gest The concept of using radioactive isotopes as "tracers" of chemical conversions was conceived and developed by inorganic chemist Georg de Hevesy (Nobel Laureate in Chemistry 1943). In 1935, he began to apply the technique to various biological processes using 32P, and his experiments revealed the dynamic character of physiology and metabolism. Following de Hevesy's lead, Samuel Ruben (University of California, Berkeley) exploited 32P in 1937,38 for investigation of phospholipid metabolism. Between 1937 and 1940, Ruben and colleague Martin Kamen spearheaded tracer studies in various biological systems using 32P, short-lived 11C, and other radioactive isotopes. During this period, Kamen was responsible for cyclotron-produced radioactive tracers and was able to sustain de Hevesy's research by supplying him with 32P. In 1940, Ruben and Kamen discovered long-lived 14C, which later proved to be a very powerful tool for analysis of complex biochemical processes, such as the path of carbon in photosynthesis. Between 1946 and 1950, 32P was used in studies of bacteriophage replication and photosynthetic metabolism. This memoir surveys the history of these early investigations. [source] | |||||||||||||