Vergleich von frontalen und nichtfrontalen Zugängen bei der operativen Behandlung von Kraniopharyngeomen

Kraniopharyngeome sind intrakranielle Tumoren aus den Zellen der Rathke-Tasche, die durch ihre Lokalisation zu schwerwiegenden neurologischen Ausfällen führen können. In dieser Arbeit wurde die Fallberichte aus veröffentlichter Literatur bezogen. Die Ergebnisse der statistischen Verfahren zeigten bei n=1014 sowohl für die Berechnung der Odds Ratio als auch für die „number needed to treat“ und die absolute Risikoreduktion einen positiveren operativen Erfolg bei der Nutzung eines frontalen operativen Zugangs. Gleiches gilt für die Ergebnisse der Konfidenzintervalle für die attributablen Risiken der Stichprobe mit CI ARR = 6%, CI NNT = 5 - 11 und CI OR 1,55 bis 2,84. Die Ergebnisse des exakten „Test nach Fisher“ sowie des Chi-Quadrat Test der Stichprobe n = 1014 zeigen mit P < 0,001 eine Signifikanz. Die Arbeitshypothese: „Patienten mit einem Kraniopharyngeom haben durch einen frontalen operativen Zugang eine größere Chance auf eine operative komplette Tumorentfernung“ konnte bejaht werden

Three-Nucleon Force and the Δ\Delta-Mechanism for Pion Production and Pion Absorption

The description of the three-nucleon system in terms of nucleon and $\Delta$ degrees of freedom is extended to allow for explicit pion production (absorption) from single dynamic $\Delta$ de-excitation (excitation) processes. This mechanism yields an energy dependent effective three-body hamiltonean. The Faddeev equations for the trinucleon bound state are solved with a force model that has already been tested in the two-nucleon system above pion-production threshold. The binding energy and other bound state properties are calculated. The contribution to the effective three-nucleon force arising from the pionic degrees of freedom is evaluated. The validity of previous coupled-channel calculations with explicit but stable $\Delta$ isobar components in the wavefunction is studied.Comment: 23 pages in Revtex 3.0, 9 figures (not included, available as postscript files upon request), CEBAF-TH-93-0

Consistent Treatment of Relativistic Effects in Electrodisintegration of the Deuteron

The influence of relativistic contributions to deuteron electrodisintegration is systematically studied in various kinematic regions of energy and momentum transfer. As theoretical framework the equation-of-motion and the unitarily equivalent S-matrix approaches are used. In a (p/M)-expansion, all leading order relativistic $\pi$-exchange contributions consistent with the Bonn OBEPQ model are included. In addition, static heavy meson exchange currents including boost terms, $\gamma\pi\rho/\omega$-currents, and $\Delta$-isobar contributions are considered. Sizeable effects from the various relativistic two-body contributions, mainly from $\pi$-exchange, have been found in inclusive form factors and exclusive structure functions for a variety of kinematic regions.Comment: 41 pages revtex including 15 postscript figure

Ad hoc Joint FAO/WHO Expert Consultation on Risk Assessment of Food Allergens Part 2: Review and establish threshold levels in foods of the priority allergens

The main purpose of this second meeting was to establish threshold levels in foods of the priority allergens. Based on the defined approach, the Expert Committee discussed and agreed on the safety objective, which could be described as “to minimise, to a point where further refinement does not meaningfully reduce health impact, the probability of any clinically relevant objective allergic response, as defined by dose distribution modelling of minimum eliciting doses (MEDs) and supported by data regarding severity of symptoms in the likely range of envisioned Reference Doses (RfD)”. The Committee further identified several important considerations to guide decision-making. These included a clear definition of criteria to be met by quantitative data on which reference doses (RfD) are based, supporting data on health manifestations (severity) at the proposed RfD, quality, quantity, availability and accessibility of data (for priority allergens), as well as how to deal with priority allergens for which information supporting one or more of those considerations was lacking.El objetivo principal de esta segunda reunión fue establecer niveles umbral en los alimentos de los alérgenos prioritarios. Sobre la base del enfoque definido, el Comité de Expertos discutió y acordó el objetivo de seguridad, que podría describirse como “minimizar, hasta un punto en el que un mayor refinamiento no reduzca significativamente el impacto en la salud, la probabilidad de cualquier respuesta alérgica objetiva clínicamente relevante, como definido por el modelo de distribución de dosis de dosis mínimas provocadoras (MED) y respaldado por datos sobre la gravedad de los síntomas en el rango probable de dosis de referencia previstas (RfD) ”. El Comité identificó además varias consideraciones importantes para orientar la toma de decisiones. Estos incluyeron una definición clara de los criterios que deben cumplir los datos cuantitativos en los que se basan las dosis de referencia (RfD), datos de apoyo sobre manifestaciones de salud (gravedad) en la RfD propuesta, calidad, cantidad, disponibilidad y accesibilidad de los datos (para alérgenos prioritarios). , así como cómo tratar los alérgenos prioritarios para los que faltaba información que respaldara una o más de esas consideraciones.Instituto de Investigación de Tecnología de AlimentosFil: Baumert, Joseph. Universidad de Nebraska-Lincoln. Departamento de Ciencia y Tecnología de Alimentos; Estados UnidosFil: Brooke-Taylor, Simon. Brooke-Taylor & Co. Consultor australiano de regulación alimentaria y análisis de riesgos (Pty Ltd); Australia.Fil: Crevel, René W.R. René Crevel Consulting Limited; Reino Unido.Fil: Houben, Geert F. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido.Fil: Jackson, Lauren. Administración de Alimentos y Medicamentos de los Estados Unidos. División de Ciencia y Tecnología del Procesamiento de Alimentos. Ingeniería de Procesos; Estados UnidosFil: Kyriakidis, Symeon. Laboratorio Estatal de Química General (GCSL).Autoridad Independiente de Ingresos Públicos (IAPR); Grecia.Fil: La Vieille, Sébastien. Universidad Laval. Departamento de Ciencias de los Alimentos; Canadá.Fil: Lee, N Alice. Universidad de Nueva Gales del Sur. Escuela de Química e Ingeniería. Ciencia e ingeniería de los alimentos; Australia.Fil: López, María Cristina. Universidad Nacional de San Martín. Ingeniería de Alimentos; Argentina.Fil: Luccioli, Stefano. Administración de Alimentos y Medicamentos de los Estados Unidos. Centro de Seguridad Alimentaria y Nutrición Aplicada; Estados UnidosFil: O’Mahony, Patrick. Autoridad de Seguridad Alimentaria de Irlanda; Irlanda.Fil: O’Mahony, Patrick. Universidad College Dublin; Irlanda.Fil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Polenta, Gustavo Alberto. Instituto de Ciencia y Tecnología de los Sistemas Alimentarios Sustentables (ICyTeSAS) UEDD INTA-CONICET; Argentina.Fil: Pöpping, Bert. Food Consulting Strategically (FOCO); Alemania.Fil: Pöpping, Bert. Comités de Normalización ISO - CEN. Grupo de trabajo CEN Alérgenos Alimentarios (CEN TC 275 WG 12).); Alemania.Fil: Remington, Benjamin C. Remington Consulting Group B.V.; Holanda.Fil: Remington, Benjamin C. Universidad de Nebraska–Lincoln. Programa de Recursos e Investigación de Alergias Alimentarias. Estados UnidosFil: Srikulnath, Sirinrat. Universidad de Kasetsart (UKaset). Instituto de Investigación y Desarrollo de Productos Alimentarios. Centro de Servicio de Aseguramiento de la Calidad de los Alimentos. Unidad de Alérgenos Alimentarios; Tailandia.Fil: Taylor, Stephen L. Universidad de Nebraska-Lincoln. Departamento de Ciencia y Tecnología de Alimentos; Estados UnidosFil: Turner, Paul J. Colegio Imperial de Ciencia, Tecnología y Medicina. Alergia e Inmunología Pediátricas; Inglaterra

Effects of Neuraxial Blockade May Be Difficult To Study Using Large Randomized Controlled Trials: The PeriOperative Epidural Trial (POET) Pilot Study

Early randomized controlled trials have suggested that neuraxial blockade may reduce cardiorespiratory complications after non-cardiothoracic surgery, but recent larger trials have been inconclusive. We conducted a pilot study to assess the feasibility of conducting a large multicentre randomized controlled trial in Canada.After Research Ethics Board approvals from the participating institutions, subjects were recruited if they were > or = 45 years old, had an expected hospital stay > or = 48 hours, were undergoing a noncardiothoracic procedure amenable to epidural analgesia, met one of six risk criteria, and did not have contraindications to neuraxial blockade. After informed consent, subjects were randomly allocated to combined epidural analgesia (epidural group) and neuraxial anesthesia, with or without general anesthesia, or intravenous opioid analgesia (IV group) and general anesthesia. The primary outcomes were the rate of recruitment and the percents of eligible patients recruited, crossed over, and followed completely. Feasibility targets were defined a priori. A blinded, independent committee adjudicated the secondary clinical outcomes. Subjects were followed daily while in hospital and then at 30 days after surgery. Analysis was intention-to-treat. Over a 15-month period, the recruitment rate was 0.5+/-0.3 (mean+/-SEM) subjects per week per centre; 112/494 (22.7%) eligible subjects were recruited at four tertiary-care teaching hospitals in Canada. Thirteen (26.5%) of 49 subjects in the epidural group crossed over to the IV group; seven (14.3%) were due to failed or inadequate analgesia or complications from epidural analgesia. Five (9.8%) of 51 subjects in the IV group crossed over to the epidural group but none were due to inadequate analgesia or complications. Ninety-eight (97.0%) of 101 subjects were successfully followed up until 30 days after their surgery.Of the criteria we defined for the feasibility of a full-scale trial, only the follow-up target was met. The other feasibility outcomes did not meet our preset criteria for success. The results suggest that a large multicentre trial may not be a feasible design to study the perioperative effects of neuraxial blockade.ClinicalTrials.gov NCT 0221260 Controlled-Trials.com ISRCTN 35629817

Pion Absorption Cross Section for ^2H and ^3He in the Delta-Isobar Region: A Phenomenological Connection

The absorption of \pi^+ on ^3He in the $\Delta$-region is evaluated with exact inclusion of the final state interaction among the three emerging protons. The absorption is described by a $\pi N \to \Delta$ vertex and a $N\Delta - NN$ transition t-matrix which are calculated from a phenomenological model for NN and \pi d reactions. In a calculation where the initial pion scattering effects are neglected, the predicted peaks of the pion absorption cross sections for ^2H and ^3He lie too high in energy in relation to the data. The effect of the final state three-nucleon interaction turns out to be too small for changing the magnitude and shifting the peak position of the total absorption cross section for ^3He. We demonstrate that the adjustment of the peak position for the deuteron cross section by small modifications of the $\Delta$-parameters, automatically leads to the correct peak position in ^3He.Comment: 12 pages, REVTeX, 10 PostScript figures, submitted to Phys. Rev.