Chirurgische Therapiestrategien beim Ösophagus- und Magenkarzinom

Zusammenfassung: Diese Übersichtsarbeit hat zum Ziel, die aktuellen chirurgischen Strategien bei der Behandlung des Ösophagus- und Magenkarzinoms zusammenzufassen. Neben den etablierten Standardverfahren wird auf die limitierten Resektionen bei Frühkarzinomen und den Stellenwert der Chirurgie im multimodalen Behandlungskonzept bei lokal fortgeschrittenen T3/4-Tumoren eingegangen. Das Plattenepithelkarzinom und das Adenokarzinom (Barrett-Karzinom) der Speiseröhre werden aufgrund der unterschiedlichen Pathogenese und Tumorbiologie sowie differenzierter unterschiedlicher Vorgehensweisen separat dargestellt. Aufgrund der überwiegend distalen Lokalisation der Barrett-Karzinome ist eine Abgrenzung zu den echten Kardiakarzinomen und Tumoren, die im Magen ihren Ursprung nehmen und die distale Speiseröhre infiltrieren, erforderlich. Basierend auf der Klassifikation nach Siewert wird das Barrett-Karzinom deshalb zusammen mit den so genannten Adenokarzinomen des ösophagogastralen Übergangs (AEG) behandelt. Für die Weiterentwicklung der chirurgischen Therapiestrategien beim Magenkarzinom haben sich die asiatischen, insbesondere japanischen und südkoreanischen Kollegen große Verdienste erworben. Moderne, dort entwickelte, aber noch nicht in der westlichen Welt etablierte Strategien werden neben den Standardverfahren gebührend berücksichtigt. Für alle diese Tumoren gilt, dass die chirurgische Therapie ein elementarer Bestandteil im Rahmen eines kurativen Behandlungskonzepts ist. Sie ist aber differenzierter und Teil eines komplexen interdisziplinären Algorithmus; deshalb ist eine weitere Spezialisierung zum Wohle der Patienten ratsa

Hartree-Fock-Bogoliubov Model and Simulation of Attractive and Repulsive Bose-Einstein Condensates

We describe a model of dynamic Bose-Einstein condensates near a Feshbach resonance that is computationally feasible under assumptions of spherical or cylindrical symmetry. Simulations in spherical symmetry approximate the experimentally measured time to collapse of an unstably attractive condensate only when the molecular binding energy in the model is correct, demonstrating that the quantum fluctuations and atom-molecule pairing included in the model are the dominant mechanisms during collapse. Simulations of condensates with repulsive interactions find some quantitative disagreement, suggesting that pairing and quantum fluctuations are not the only significant factors for condensate loss or burst formation. Inclusion of three-body recombination was found to be inconsequential in all of our simulations, though we do not consider recent experiments [1] conducted at higher densities

A stringent preemptive protocol reduces cytomegalovirus disease in the first 6 months after kidney transplantation

Background: The optimal strategy to prevent cytomegalovirus (CMV) disease after kidney transplantation continues to be open to debate. The preemptive approach requires regular determination of CMV viremia and prompt initiation of therapy. Methods: We retrospectively compared the incidence of CMV disease during two periods at our center: A first phase (P1, n=84 kidney recipients), during which time the intensity of surveillance was determined by the responsible physician, was compared to a second phase (P2, n=74), when a stringent protocol of CMV surveillance was required for all patients. The preemptive approach was applied for all CMV risk groups; prophylaxis was optional in the case of treatment for rejection or delayed graft function in the intermediate- and high-risk group. Follow-up was truncated at 6months after transplant surgery. CMV syndrome was differentiated from asymptomatic replication by the presence of at least one systemic symptom, while diagnosis of CMV end-organ disease required histological confirmation. Results: Immunosuppression was similar in the two periods. CMV prophylaxis was used equally (26%) in both periods. The probability for asymptomatic viremia episodes was not different for patients in P1 and P2 regardless of the prevention strategy. For patients following the preemptive strategy, the probability for CMV disease was increased during P1 (p=0.016), despite fewer PCR assays being performed in phase 2. Protocol violations were only observed during P1. Conclusions: The probability of CMV disease episodes (CMV syndrome and CMV end-organ disease) was substantially reduced using a very stringent protocol. This study highlights the crucial importance of a stringent protocol with optimal adherence by all caregivers if the preemptive strategy is to be successfu

Intramolecular homolytic substitution in selenoxides and selenones

G3(MP2)-RAD calculations provide activation energies for intramolecular homolytic substitution in the 4-(alkylselenoxo)butyl and 4-(alkylselendioxo)butyl radicals ranging from 21–39 kJ mol−1, and 143–170 kJ mol−1 for the selenoxide and selenone, respectively. Arrhenius data translate into rate constants for ring-closure of 1.5×105−2.5×108 s−1 (80°) for the selenoxides, and 5.4×10−14−5.1×10−11 s−1 (80°) for the corresponding selenones. NBO analyses show alkyl radicals are electrophilic during homolytic substitution at selenoxide selenium. The dominant orbital interaction in the transition state is worth 2413 kJ mol−1 and involves the SOMO and the lone-pair of electrons on selenium. The corresponding selenones are calculated to ring-close through transition states in which alkyl radicals are nucleophilic, but involve weak (SOMO--> σ* and SOMO--> π*) interactions. Consequently, this chemistry is not viable for selenones because of the lack of lone-pairs of electrons on the chalcogen

Intrahepatisches Sarkom der follikulär-dendritischen Zellen

Zusammenfassung: Wir berichten über ein primär intrahepatisches Sarkom der follikulär-dendritischen Zellen, das bei einer 76-jährigen Patientin auf dem Boden eines Morbus Castleman vom hyalin-vaskulären Typ auftrat. Wir diskutieren die klinisch-pathologischen Befunde, die Pathogenese und das differenzialdiagnostische Vorgehen bei diesem seltenen Tumorty

A tool for predicting the dynamic response of biotrickling filters for VOC removal

This article presents the development of a MATLAB® computer program to simulate the performance of biotrickling filters. Since these filters behave differently during spraying and nonspraying cycles, the presented simulation tool is built on top of a mathematical description of each situation. The resulting variable-structure model is then used as the basis for simulation experiments. The model presented herein represents the first attempt to take into account the variable spraying pattern usually found in industrial installations. Overall, the software is flexible and easy to use, allowing the user to specify the emission concentration pattern, the gas concentration pattern, as well as the spraying cycle periods for up to two different emission patterns per day. The model is able to predict experimental data from a biotrickling filter treating isopropanol under intermittent conditions of loading and spraying. Simulation examples are then provided to study the effect of variable inlet concentrations and gas flow rates

Proactively Monitoring Departmental Clinical IT Systems with an Open Source Availability System

The goal of all radiology information technology (IT) support organizations is excellent customer service through the availability of critical clinical information services, such as picture archiving communication systems and radiology information systems. Despite these goals, IT support personnel often act like firefighters, reacting to each problem, but unable to prevent or predict other problems. Proactive support is always more desirable than reactive support. Warning signs may exist well before a technical issue becomes system wide or the user is affected. The objective for IT support organizations in health care should be to maximize system uptime by using proactive monitoring systems for failures and to automatically detect failures through systems management tools. We report on the implementation of Nagios, an open source monitoring tool, as an availability management system in a diagnostic imaging department and on customized applications and protocols specific to radiology needs

Relativistic Wavepackets in Classically Chaotic Quantum Cosmological Billiards

Close to a spacelike singularity, pure gravity and supergravity in four to eleven spacetime dimensions admit a cosmological billiard description based on hyperbolic Kac-Moody groups. We investigate the quantum cosmological billiards of relativistic wavepackets towards the singularity, employing flat and hyperbolic space descriptions for the quantum billiards. We find that the strongly chaotic classical billiard motion of four-dimensional pure gravity corresponds to a spreading wavepacket subject to successive redshifts and tending to zero as the singularity is approached. We discuss the possible implications of these results in the context of singularity resolution and compare them with those of known semiclassical approaches. As an aside, we obtain exact solutions for the one-dimensional relativistic quantum billiards with moving walls.Comment: 18 pages, 10 figure

Metabolic Changes in Skin Caused by Scd1 Deficiency: A Focus on Retinol Metabolism

We previously reported that mice with skin-specific deletion of stearoyl-CoA desaturase-1 (Scd1) recapitulated the skin phenotype and hypermetabolism observed in mice with a whole-body deletion of Scd1. In this study, we first performed a diet-induced obesity experiment at thermoneutral temperature (33°C) and found that skin-specific Scd1 knockout (SKO) mice still remain resistant to obesity. To elucidate the metabolic changes in the skin that contribute to the obesity resistance and skin phenotype, we performed microarray analysis of skin gene expression in male SKO and control mice fed a standard rodent diet. We identified an extraordinary number of differentially expressed genes that support the previously documented histological observations of sebaceous gland hypoplasia, inflammation and epidermal hyperplasia in SKO mice. Additionally, transcript levels were reduced in skin of SKO mice for genes involved in fatty acid synthesis, elongation and desaturation, which may be attributed to decreased abundance of key transcription factors including SREBP1c, ChREBP and LXRα. Conversely, genes involved in cholesterol synthesis were increased, suggesting an imbalance between skin fatty acid and cholesterol synthesis. Unexpectedly, we observed a robust elevation in skin retinol, retinoic acid and retinoic acid-induced genes in SKO mice. Furthermore, SEB-1 sebocytes treated with retinol and SCD inhibitor also display an elevation in retinoic acid-induced genes. These results highlight the importance of monounsaturated fatty acid synthesis for maintaining retinol homeostasis and point to disturbed retinol metabolism as a novel contributor to the Scd1 deficiency-induced skin phenotype