Postoperative Komplikationen und Verweildauer nach kolonchirurgischen Eingriffen:eine retrospektive Studie

Fragestellung: Bei Operationen kann es zu Komplikationen kommen. Es wird gezeigt, welche Komplikationen auftraten und welche Parameter sie beeinflussen. Des Weiteren wurde die Verweildauer untersucht. Zudem wird gezeigt, ob die Clavien-Dindo-Klassifikation hilfreich ist. Methoden: Es wurden 186 kolonchirurgische Eingriffe selektiert, die zwischen Januar 2006 und September 2007 durchgeführt wurden. Von diesen wurden Risikofaktoren, Komplikationen sowie Verweildauer ermittelt. Ergebnisse: Es findet sich eine Gesamtkomplikationsrate von 40,9 %. Ein erhöhtes Risiko besteht bei Patienten mit Untergewicht, Notfall-OPs, OPs primär ohne Anastomose und langer OP-Dauer. Die Mortalitätsrate lag bei 3,8 % und ist erhöht bei konventionellen Eingriffen, Hand-Anastomosen und Notfalleingriffen. Die durchschnittliche Aufenthaltsdauer betrug 13,9 (± 10,1) Tage. Sie ist abhängig von Komplikationen, Patientenalter, OP-Verfahren und Vorliegen eines Karzinoms. Die Einteilung von Komplikationen nach Clavien-Dindo korreliert mit der Verweildauer. Schlussfolgerung: Morbidität, Mortalität und Verweildauer sind abhängig von Alter, Gewicht, OP-Dauer, Notfallversorgung, OP-Verfahren, Anastomosenart, Vorliegen eines Malignoms und Komplikationen. Mit der Clavien-Dindo-Klassifikation liegt ein Instrument zur Einstufung postoperativer Komplikationen vor

Insights into biofilm dispersal regulation from the crystal structure of the PAS-GGDEF-EAL region of RbdA from Pseudomonas aeruginosa

© 2018 American Society for Microbiology. RbdA is a positive regulator of biofilm dispersal of Pseudomonas aeruginosa. Its cytoplasmic region (cRbdA) comprises an N-terminal Per-ARNT-Sim (PAS) domain followed by a diguanylate cyclase (GGDEF) domain and an EAL domain, whose phosphodiesterase activity is allosterically stimulated by GTP binding to the GGDEF domain. We report crystal structures of cRbdA and of two binary complexes: one with GTP/Mg 2+ bound to the GGDEF active site and one with the EAL domain bound to the c-di-GMP substrate. These structures unveil a 2-fold symmetric dimer stabilized by a closely packed N-terminal PAS domain and a noncanonical EAL dimer. The autoinhibitory switch is formed by an α-helix (S-helix) immediately N-terminal to the GGDEF domain that interacts with the EAL dimerization helix (α6-E) of the other EAL monomer and maintains the protein in a locked conformation. We propose that local conformational changes in cRbdA upon GTP binding lead to a structure with the PAS domain and S-helix shifted away from the GGDEF-EAL domains, as suggested by small-angle X-ray scattering (SAXS) experiments. Domain reorientation should be facilitated by the presence of an α-helical lever (H-helix) that tethers the GGDEF and EAL regions, allowing the EAL domain to rearrange into an active dimeric conformation

Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Structure and subunit arrangement of the A-type ATP synthase complex from the archaeon Methanococcus jannaschii visualized by electron microscopy

In Archaea, bacteria, and eukarya, ATP provides metabolic energy for energy-dependent processes. It is synthesized by enzymes known as A-type or F-type ATP synthase, which are the smallest rotatory engines in nature (Yoshida, M., Muneyuki, E., and Hisabori, T. (2001) Nat. Rev. Mol. Cell. Biol. 2, 669-677; Imamura, H., Nakano, M., Noji, H., Muneyuki, E., Ohkuma, S., Yoshida, M., and Yokoyama, K. (2003) Proc. Natl. Acad. Sci. U. S. A. 100, 2312-2315). Here, we report the first projected structure of an intact A(1)A(0) ATP synthase from Methanococcus jannaschii as determined by electron microscopy and single particle analysis at a resolution of 1.8 nm. The enzyme with an overall length of 25.9 nm is organized in an A(1) headpiece (9.4 x 11.5 nm) and a membrane domain, A(0) (6.4 x 10.6 nm), which are linked by a central stalk with a length of approximately 8 nm. A part of the central stalk is surrounded by a horizontal-situated rodlike structure ("collar"), which interacts with a peripheral stalk extending from the A(0) domain up to the top of the A(1) portion, and a second structure connecting the collar structure with A(1). Superposition of the three-dimensional reconstruction and the solution structure of the A(1) complex from Methanosarcina mazei Gö1 have allowed the projections to be interpreted as the A(1) headpiece, a central and the peripheral stalk, and the integral A(0) domain. Finally, the structural organization of the A(1)A(0) complex is discussed in terms of the structural relationship to the related motors, F(1)F(0) ATP synthase and V(1)V(0) ATPases

Structural characterization of an ATPase active F-1-/V-1-ATPase (alpha(3)beta(3)EG) hybrid complex

Co-reconstitution of subunits E and G of the yeast V-ATPase and the α and β subunits of the F1-ATPase from the thermophilic Bacillus PS3 (TF1) resulted in an α3β3EG hybrid complex showing 53% of the ATPase activity of TF1. The α3β3EG oligomer was characterized by electron microscopy. By processing 40,000 single particle projections, averaged two-dimensional projections at 1.2–2.4-nm resolution were obtained showing the hybrid complex in various positions. Difference mapping of top and side views of this complex with projections of the atomic model of the α3β3 subcomplex from TF1 demonstrates that a seventh mass is located inside the shaft of the α3β3 barrel and extends out from the hexamer. Furthermore, difference mapping of the α3β3EG oligomer with projections of the A3B3E and A3B3EC subcomplexes of the V1 from Caloramator fervidus shows that the mass inside the shaft is made up of subunit E, whereby subunit G was assigned to belong at least in part to the density of the protruding stalk. The formation of an active α3β3EG hybrid complex indicates that the coupling subunit γ inside the α3β3 oligomer of F1 can be effectively replaced by subunit E of the V-ATPase. Our results have also demonstrated that the E and γ subunits are structurally similar, despite the fact that their genes do not show significant homology