309 research outputs found
Weight reduction and bone loss in postmenopausal women: follow up at 2 years
No full textShort-term weight loss (WL) is accompanied by bone loss in postmenopausal women, but the longer-term impact is unclear. The goal of this study was to determine whether weight regain compared to maintenance of WL in reduced obese/overweight women has an impact on bone mineral density (BMD) and content (BMC). It was hypothesized that weight regain in reduced obese women would result in partial recovery of bone, as compared to women who maintain their lost weight. We measured hip, spine, forearm, and total body BMD and BMC by dual energy x-ray absorptiometry. Hormones, markers of bone turnover, and soft tissue were assessed. We recruited postmenopausal women (n=40, BMI of 28.2 +/- 2.9 kg/m2; 60.6 +/- 5.6 years) 1.5 years after a 6 month weight loss program who were categorized as regaining (>75%) or maintaining their weight lost. After 6 mo of WL, both groups lost -9.1 +/- 3.1% body weight with no significant difference between groups. At 23 +/- 6 mo after baseline, the weight-loss maintainers (WL-M, n=22) and weight-loss re-gainers (WL-R, n=18) lost -10.4 +/- 4.3 % and -2.6 +/- 3.6 % of their body weight. Participants averaged 1228 +/- 529 mg/d during the follow-up period, which did not differ significantly between the groups. The WL-M group showed greater BMD loss at the trochanter (p0.422, p<0.01), but not trunk fat, suggesting that regional fat tissue may have a differential influence on bone. These data in postmenopausal women show that bone continues to decline at the trochanter and femoral neck over a 2 year period with 10% weight loss, and with weight regain there is partial recovery of bone.M.S.Includes bibliographical references (p. 42-49)by Nancy L. von Thu
The meaning of 3,4-methylenedioxymethamphetamine ("ecstasy") as trigger of malignant hyperthermia
No full textDie Maligne Hyperthermie ist eine in der Anästhesie gefürchtete akut eintretende Komplikation, welche durch bestimmte Triggersubstanzen ausgelöst werden kann. Vor dem Hintergrund zahlreicher Literaturangaben kann spekuliert werden, dass auch 3,4-Methylendioxymethamphetamin („Ecstasy“) ein Auslöser der Malignen Hyperthermie ist. Für diese Hypothese gibt es mehrere klinische und experimentelle Anhaltspunkte:
1. Der Verlauf des klinischen Erscheinungsbildes einer MDMA-Intoxikation ähnelt sehr der Symptomatik einer MH-Krise.
2. Das MH-spezifische Antidot Dantrolen wurde auch bei der Therapie der durch MDMA-Intoxikation hervorgerufenen Hyperthermie erfolgreich eingesetzt.
3. Bei Betrachtung des pathophysiologischen Mechanismus der MH wurde belegt, dass durch Überstimulation des Serotoninsystems eine MH-Krise ausgelöst werden kann. Ecstasy bewirkt ebenso eine serotonerge Überstimulation und kommt somit als Auslöser einer MH in Frage.
4. Es konnte eine direkte Wirkung von Ecstasy am humanen Skelettmuskel nachgewiesen werden. Dabei führte die alleinige Gabe von Ecstasy bei MHS-Muskeln zu einer ausgeprägten Kontrakturentwicklung, wohingegen bei MHN-Muskeln keine Kontraktur auslösbar war. Der Effekt war daher mit anderen Triggersubstanzen vergleichbar.
Aufgrund der vorliegenden klinischen Beobachtungen und Untersuchungsergebnisse stellen wir die Hypothese auf, dass es sich bei Ecstasy um eine Triggersubstanz der MH handelt. Ziel dieser Arbeit war daher für Ecstasy die MH-Triggerpotenz zu klären und eine mögliche Kontraindikation bei MH-Disposition zu belegen oder auszuschließen.
Zur Prüfung dieser Hypothese wurde in einem in-vivo Versuch MHS- und MHN–Schweinen MDMA in ansteigender Dosis appliziert und die Reaktion des Organismus im Hinblick auf die Entwicklung einer MH-Krise registriert.
Es wurden die folgenden Ergebnisse gewonnen:
1. „Ecstasy“ ist ein Trigger der Malignen Hyperthermie beim suszeptiblen Schwein. Die in dieser Untersuchung verwendeten kumulativen Ecstasy-Konzentrationen waren mit denen von Menschen eingenommene Konzentrationen vergleichbar. Somit besteht der Verdacht, das „Ecstasy“ auch bei MH-suszeptiblen Menschen eine Maligne Hyperthermie triggern könnte. Ein Konsum von Ecstasy ist daher für MHS-Patienten absolut kontraindiziert.
2. Die Therapie des „Ecstasy“-induzierten Hyperthermiesyndroms mittels der Gabe von Dantrolen verlief in diesem Experiment erfolgreich. Als Fazit für die Praxis folgt daraus, dass bei Patienten mit MDMA-Intoxikation ein Therapieversuch mit Dantrolen indiziert ist.
3. Zur Verbesserung der Sicherheit von MH-disponierten Patienten sollte sich dieser Personenkreis nach MDMA-induziertem hypermetabolischem Syndrom einer MH-Diagnostik mit dem Halothan-und Koffein-in-vitro Kontrakturtest unterziehen.
4. Die MHN-Schweine reagierten ebenfalls mit einer hypermetabolen Stoffwechselentgleisung auf die Ecstasy-Applikation, die jedoch deutlich milder verlief. Es wurden keine MH-typischen Kriterien im Sinne einer MH-Krise erfüllt.3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") can mediate acute toxic effects such as muscle rigidity, metabolic acidosis, and hyperthermia. Because of close clinical similarities, an association between MDMA intoxication and malignant hyperthermia (MH) was suggested. The aim of this study was to investigate whether MDMA is a trigger of MH in susceptible swine. METHODS: MH-nontriggering general anesthesia was performed in six MH-susceptible (MHS) and six MH-normal swine. The animals were exposed to MDMA in cumulative doses of 0.5, 1, 2, 4, 8, and 12 mg/kg. The clinical occurrence of MH was defined by achievement of two of three conditions: central venous Pco2 >/=75 mmHg, central venous pH </= 7.20, and increase of body core temperature >/= 2.0 degrees C. Once MH occurred, a standardized therapy with dantrolene, sodium bicarbonate, and hyperventilation with 100% oxygen was initialized. RESULTS: Administration of 8 mg/kg MDMA triggered MH in all MHS swine. The MH-normal swine also developed clinical signs of hypermetabolism, but even after administration of 12 mg/kg MDMA, changes were moderate compared with the MHS swine. Dantrolene therapy of MDMA-induced MH crisis in the MHS swine partially counteracted the clinical signs of MH immediately.
CONCLUSIONS: MDMA induces MH in genetically susceptible swine in relevant doses. Therefore, MHS patients should avoid use of MDMA or related drugs. Patients with a personal or family history of MDMA-induced hyperthermia should be tested for a diagnosis of MH susceptibility. Dantrolene is effective in therapy of MDMA-induced porcine MH
Systematic Review of Escalated Imatinib Doses Compared with Sunitinib or Best Supportive Care, for the Treatment of People with Unresectable/Metastatic Gastrointestinal Stromal Tumours Whose Disease has Progressed on the Standard Imatinib Dose
No full textPMID: 21971958 [PubMed - indexed for MEDLINE] PMCID: PMC3348468 Free PMC Article This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are creditedPeer reviewe
Honour and recognition in the German novel of banditry ca 1800
No full textThis article performs a reading informed by Honneth’s theory of recognition of the two best-known German novels of banditry of the 1790s, Johann Heinrich Zschokke’s Abaellino der große Bandit (1794) and Christian August Vulpius’ Rinaldo Rinaldini (1799) in an effort to understand how popular literature participates in and reflects upon the discourse on honour and recognition around 1800. Its status as popular genre makes the novel of banditry (Räuberroman) a potentially interesting source on shifts in the theory and practice of honour as experienced by ordinary Europeans at the turn of the 19th century. The genre was found to relate to the honour discourse not directly, but in the manner of a heterotopia, simultaneously located outside that discourse and referentially connected to it. Taken in isolation, the novel of banditry is not an informative source on the changing role of honour and new patterns of intersubjective recognition in late 18th century Europe. Seen as part of a particular constellation of textual production and reception, however, the genre sheds light on the aporias of honour experienced by those socially marginal ‘new readers’ intent on exploiting literature in the struggle for enhanced social recognition.Peer reviewe
Rate of telomere shortening and cardiovascular damage: a longitudinal study in the 1946 British Birth Cohort.
No full textCross-sectional studies reported associations between short leucocyte telomere length (LTL) and measures of vascular and cardiac damage. However, the contribution of LTL dynamics to the age-related process of cardiovascular (CV) remodelling remains unknown. In this study, we explored whether the rate of LTL shortening can predict CV phenotypes over 10-year follow-up and the influence of established CV risk factors on this relationship
Avaliação técnico-econômica de alternativas de lodos ativados no tratamento de esgotos domésticos
No full textTCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia Sanitária e Ambiental.O tratamento de esgotos no Brasil situa-se num cenário de grandes desafios, sendo o sistema de Lodos Ativados uma importante tecnologia, largamente utilizada e com elevada eficiência de tratamento. Este estudo tem como objetivo avaliar os custos e benefícios de três sistemas de tratamento de esgotos, por variantes da tecnologia de lodos ativados, dimensionados para atender uma população de 100.000 habitantes. É estabelecido um cenário de mesmos parâmetros ambientais para as alternativas consideradas, com as seguintes premissas: (i) necessidade de 90% de eficiência na remoção de carga orgânica (DQO); (ii) necessidade de nitrificação (80%) e (iii) desnitrificação (60%); (iv) estabilização do lodo por processos aeróbios ou anaeróbios.Para estabelecer a comparação entre as alternativas, é aplicada a metodologia de custo do ciclo de vida. Esta metodologia se traduz num método de cálculo da totalidade dos custos inerentes ao projeto, durante toda a vida do mesmo. Os custos e benefícios associados aos respectivos sistemas de tratamento de esgotos são identificados e classificados. Os custos refletem todas as despesas do projeto em questão, desde as primeiras despesas até o fim da vida útil do projeto, e são classificados como custos de investimento inicial, e custos de OM&R (operação, manutenção e reparação). Com o objetivo de simplificar o estudo, o custo de desidratação do lodo não será considerado, apenas será considerado o custo para disposição de lodo em aterro sanitário. Os custos das alternativas avaliadas relevam principalmente os seguintes aspectos: área construída, custos de implantação de obras civis e aquisição de equipamentos, consumo de energia, custo de disposição de lodo, potencial de aproveitamento energético do biogás
Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths
No full textAuthor Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 75 (2011): 5247-5268, doi:10.1016/j.gca.2011.06.026.We present whole rock Li and Mg isotope analyses of 33 ultramafic xenoliths from
the terrestrial mantle, which we compare with analyses of 30 (mostly chondritic)
meteorites. The accuracy of our new Mg isotope ratio measurement protocol is
substantiated by a combination of standard addition experiments, the absence of mass
independent effects in terrestrial samples and our obtaining identical values for rock
standards using 2 different separation chemistries and 3 different mass-spectrometric
introduction systems. Carbonaceous, ordinary and enstatite chondrites have
irresolvable mean stable Mg isotopic compositions (δ25Mg = -0.14 ± 0.06; δ26Mg = -
0.27 ± 0.12‰, 2sd), but our enstatite chondrite samples have lighter δ7Li (by up to
~3‰) than our mean carbonaceous and ordinary chondrites (3.0 ± 1.5‰, 2sd),
possibly as a result of spallation in the early solar system. Measurements of
equilibrated, fertile peridotites give mean values of δ7Li = 3.5 ± 0.5‰, δ25Mg = -0.10
± 0.03‰ and δ26Mg = -0.21 ± 0.07‰. We believe these values provide a useful
estimate of the primitive mantle and they are within error of our average of bulk
carbonaceous and ordinary chondrites. A fuller range of fresh, terrestrial, ultramafic
samples, covering a variety of geological histories, show a broad positive correlation
between bulk δ7Li and δ26Mg, which vary from -3.7 to +14.5‰, and -0.36 to +0.06‰,
respectively. Values of δ7Li and δ26Mg lower than our estimate of primitive mantle
are strongly linked to kinetic isotope fractionation, occurring during transport of the
mantle xenoliths. We suggest Mg and Li diffusion into the xenoliths is coupled to H loss from nominally anhydrous minerals following degassing. Diffusion models
suggest that the co-variation of Mg and Li isotopes requires comparable diffusivities
of Li and Mg in olivine. The isotopically lightest samples require ~5-10 years of
diffusive ingress, which we interpret as a time since volatile loss in the host magma.
Xenoliths erupted in pyroclastic flows appear to have retained their mantle isotope
ratios, likely as a result of little prior degassing in these explosive events. High δ7Li,
coupled with high [Li], in rapidly cooled arc peridotites may indicate that these
samples represent fragments of mantle wedge that has been metasomatised by heavy,
slab-derived fluids. If such material is typically stirred back into the convecting
mantle, it may account for the heavy δ7Li seen in some oceanic basalts.PPvS was supported
by NERC grant NER/C510983/
Feasibility of charge exchange spectroscopy fast helium measurements on ITER
No full textThe feasibility to measure fast alpha particles using Active Charge Exchange Recombination Spectroscopy (CXRS) on ITER is investigated. Through modelling of the charge exchange spectral line for fast ions together with the expected background emission, the signal-to-noise ratio has been calculated as a function of the diagnostic design parameters. Combining the CXRS data from both the heating and the diagnostic neutral beams on ITER, information on the fast ion energy spectrum up to 1 MeV can be obtained for the parameters of the ITER core CXRS diagnostic design, provided that the signal is binned in 100 keV bins and a time resolution of Isec is used
Bayesian estimation of Zeff in the TEXTOR tokamak from visible bremsstrahlung and CXRS measurements
No full textThe determination of Z(eff) in a fusion plasma is associated with many difficulties. Several diagnostic methods exist for this purpose, each with its specific weaknesses. Here we consider the derivation of Z(eff) from bremsstrahlung measurements in the visible and from a weighted summation of individual impurity densities, calculated from CXRS intensities. In a first approach towards an improved estimation of Z(eff), which is consistent with both measurement sets, we combine in a single model the measurement of visible bremsstrahlung emissivities and carbon densities obtained from CXRS. Together with Z(eff), the electron density ne is estimated using a hybrid Gibbs-Metropolis-Hastings MCMC algorithm. Some first results are presented and some improvements in and extensions of the employed model are discussed
Optische Erfassung und biophysikalische Bewertung von Patientenbewegungen und -fehlpositionierungen in der fraktionierten Strahlentherapie
No full textDie vorliegende Arbeit befasst sich mit der Ermittlung, Simulation und Bewertung von Positionierfehlern in der fraktionierten Strahlentherapie. Die experimentelle Komponente lag auf der Erprobung und Anwendung eines photogrammetrischen Messsystems, das mit einer maximalen zeitlichen Aufloesung von 12 Millisekunden und einer theoretischen raeumlichen Aufloesung von ca. 10 Mikrometern die Bewegung eines vorgegebenen Zielpunktes im Patientenkopf dreidimensional erfassen kann. Mit dieser Apparatur wurden Genauigkeitsmessungen an zwei Kopfhalterungen fuer die fraktionierte Strahlentherapie durchgefuehrt. Es zeigte sich, dass die Positioniergenauigkeit der am Deutschen Krebsforschungszentrum (dkfz) entwickelten Maske fuer stereotaktisch gefuehrte Bestrahlungen derjenigen der thermoplastischen Vergleichsmaske deutlich ueberlegen ist. Eine Moeglichkeit zur Einbeziehung bekannter Positionierfehler in die computergestuetzte Bestrahlungsplanung ist die Simulation des Fehlers durch Faltung der berechneten Dosisverteilung mit einer Fehlerverteilungsfunktion. Die optische Messapparatur kann zur Ermittlung von Simulationsparametern fuer den Kopf-Hals-Bereich verwendet werden, falls die Transformationsvorschrift der Koordinatensysteme der Fehlermessungen und der Dosisdatensaetze bekannt ist oder zumindest abgeschaetzt werden kann. Dosis-Volumen-Histogramme sind zur Bewertung der Strahlenwirkung insbesondere bei fraktionierter Bestrahlung haeufig nicht ausreichend. Daher wurden zusaetzlich Algorithmen zur Berechnung von Komplikationswahrscheinlichkeiten im Normalgewebe und von Tumorkontrollwahrscheinlichkeiten verwendet. (orig./MG)The author addresses the detection, simulation and assessment of positioning errors in fractionated radiotherapy. The experimental component comprised the testing and application of a photogrammetry measurement system which has a maximal temporal resolution of 12 milliseconds and a theoretical spatial resolution of c. 10 micrometers and which was used to detect the movement of a specified target point within the patient's skull in a three-dimensional manner. This apparatus was used to perform accuracy measurements in two head holders for fractionated radiotherapy. It was found that the positioning accuracy of the mask developed at the Deutsches Krebsforschungszentrum (dkfz) was superior to the thermoplastic mark used for comparison in stereotactically guided irradiation. One way to include known positioning errors in computer-aided irradiation planning is to simulate errors by folding the dose distribution calculated with an error distribution function. Dose-volume histograms for assessing radiation effect, espec. in fractionated irradation, are often insufficient. That is why the author also used algorithms to calculate complication probabilities in normal tissue and tumour control probabilities. (orig./MG)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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