Monotherapy with boosted protease inhibitors as antiretroviral treatment simplification strategy in the clinical setting

Antiretroviral treatment simplification with darunavir/ritonavir or lopinavir/ritonavir monotherapy maintains sustained HIV viremia suppression in clinical trials. However, data about the efficacy of this strategy in routine clinical practice is still limited, and no direct comparison between darunavir/ritonavir and lopinavir/ritonavir has been performed to date. We retrospectively studied all HIV-1-infected subjects who initiated monotherapy with darunavir/ritonavir or lopinavir/ritonavir while having plasma VL<50 c/mL, and had at least 1 subsequent follow-up visit in our clinic. When two consecutive PI-monotherapy regimens were used, each regimen was considered separately. The primary endpoint was the percentage of patients who maintained virological suppression (HIV-1 VL <50 c/mL) through follow-up. Virological failure was defined as at least two consecutive HIV-1 VL >50 c/mL. We also evaluated other reasons for treatment discontinuation. Analyses were performed considering all regimens (full dataset analysis) either as “on treatment” or as “treatment switch equals failure”. Five hundred and seventy-three PI-monotherapy regimens corresponding to 520 subjects were included, 262 with darunavir/ritonavir and 311 with lopinavir/ritonavir. Medians (IQR) follow-up were 50 (26.3–107.6) and 85.6 (36.9–179.1) weeks for subjects on darunavir/ritonavir and lopinavir/ritonavir, respectively (p<0.001). Overall, 67 (11.7%) subjects experienced virological failure, 23 (8.7%) were on darunavir/ritonavir and 42 (13.5%) were on lopinavir/ritonavir (p=0.796). Two hundred and three (77.5%) patients on darunavir/ritonavir and 154 (49.5%) on lopinavir/ritonavir maintained virological suppression in the “treatment switch equals failure” (p=0.002). Other reasons for treatment discontinuation were gastrointestinal toxicity and dyslipidemia in 7.2% and 5.9% of cases, respectively. Gastrointestinal toxicities and dyslipidemia leading to treatment discontinuation were more frequent in patients on lopinavir/ritonavir (10.6% and 10.3%, respectively) than in patients on darunavir/ritonavir (3.1% and 0.8%, respectively). Monotherapy with darunavir/ritonavir or lopinavir/ritonavir as simplification strategy appears to be effective and safe in subjects with virological suppression in clinical practice. Virological efficacy seems to be similar between regimens. However, rates of discontinuation due to toxicities were higher in subjects on lopinavir/ritonavir than darunavir/ritonavir

Einbindung des ECOLOG-Modells "E3Net" und Integration neuer methodischer Ansätze in das IKARUS-Instrumentarium (ECOLOG II)

Ziel des Forschungsvorhabens „Einbindung des ECOLOG-Modells ‘E³Net’ und Integration neuer methodischer Ansätze in das IKARUS-Instrumentarium (ECOLOG II)' war es, veschiedene Modellbildungsansätze und Werkzeuge für die energiewirtschaftliche Analyse zu einem Instrumentarium zusammenzufügen. Dazu wurde auf die Projekte IKARUS „Instrumente für Klimagasreduktionsstrategien' und ECOLOG „Entwicklung eines Computermodells mit linearer Optimierung zur Abbildung eines regionalisierten Energiesystems am Beispiel Gesamtdeutschlands' aufgebaut. Das Projekt ECOLOG II umfaßt Weiterentwicklungen in den folgenden sechs Aufgabenbereichen: (1) Integration von E³Net in das IKARUS-Instrumentarium; (2) Nichtlineare Modellansätze für E³Net; (3) Makroökonomische Erweiterung von E³Net; (4) Entwicklung und Anwendung eines multisektoralen Energiewirtschaftsmodells NEWAGE; (5) Entwicklung eines Simulationsansatzes für Energiesystemmodelle PlaNet; (6) Erweiterung der Analysemöglichkeiten von NetWork. Im Rahmen des Forschungsvorhabens wurden eine Kopplung der FIZ-Technik-Datenbank an die Datenbank NetWork, eine Verbindung der FIZ-LP-Datenbank mit NetWork, eine Überführung des IKARUS-LP-Datensatzes in eine Fallstudie für das optimierende Energiesystemmodell E³Net, ein optimierendes Energiesystemmodell mit preiselastischer Nachfrage E³Micro, ein Gleichgewichtsmodell NEWAGE, das prototypisch ein prozeßtechnisches Energieversorgungsmodell in ein übergeordnetes gesamtwirtschaftliches Modell integriert, ein Simulationsmodell PlaNet sowie ein Netzwerkdesigner und -analyst (NDA) realisiert und durch exemplarische Fallstudien, die im Kontext des IKARUS-Instrumentariums stehen, getestet

Einbindung des ECOLOG-Modells "E3Net" und Integration neuer methodischer Ansätze in das IKARUS-Instrumentarium (ECOLOG II)

Ziel des Forschungsvorhabens „Einbindung des ECOLOG-Modells ‘E³Net’ und Integration neuer methodischer Ansätze in das IKARUS-Instrumentarium (ECOLOG II)' war es, veschiedene Modellbildungsansätze und Werkzeuge für die energiewirtschaftliche Analyse zu einem Instrumentarium zusammenzufügen. Dazu wurde auf die Projekte IKARUS „Instrumente für Klimagasreduktionsstrategien' und ECOLOG „Entwicklung eines Computermodells mit linearer Optimierung zur Abbildung eines regionalisierten Energiesystems am Beispiel Gesamtdeutschlands' aufgebaut. Das Projekt ECOLOG II umfaßt Weiterentwicklungen in den folgenden sechs Aufgabenbereichen: (1) Integration von E³Net in das IKARUS-Instrumentarium; (2) Nichtlineare Modellansätze für E³Net; (3) Makroökonomische Erweiterung von E³Net; (4) Entwicklung und Anwendung eines multisektoralen Energiewirtschaftsmodells NEWAGE; (5) Entwicklung eines Simulationsansatzes für Energiesystemmodelle PlaNet; (6) Erweiterung der Analysemöglichkeiten von NetWork. Im Rahmen des Forschungsvorhabens wurden eine Kopplung der FIZ-Technik-Datenbank an die Datenbank NetWork, eine Verbindung der FIZ-LP-Datenbank mit NetWork, eine Überführung des IKARUS-LP-Datensatzes in eine Fallstudie für das optimierende Energiesystemmodell E³Net, ein optimierendes Energiesystemmodell mit preiselastischer Nachfrage E³Micro, ein Gleichgewichtsmodell NEWAGE, das prototypisch ein prozeßtechnisches Energieversorgungsmodell in ein übergeordnetes gesamtwirtschaftliches Modell integriert, ein Simulationsmodell PlaNet sowie ein Netzwerkdesigner und -analyst (NDA) realisiert und durch exemplarische Fallstudien, die im Kontext des IKARUS-Instrumentariums stehen, getestet

Association of the Chromosome Replication Initiator DnaA with the Escherichia coli Inner Membrane In Vivo: Quantity and Mode of Binding

DnaA initiates chromosome replication in most known bacteria and its activity is controlled so that this event occurs only once every cell division cycle. ATP in the active ATP-DnaA is hydrolyzed after initiation and the resulting ADP is replaced with ATP on the verge of the next initiation. Two putative recycling mechanisms depend on the binding of DnaA either to the membrane or to specific chromosomal sites, promoting nucleotide dissociation. While there is no doubt that DnaA interacts with artificial membranes in vitro, it is still controversial as to whether it binds the cytoplasmic membrane in vivo. In this work we looked for DnaA-membrane interaction in E. coli cells by employing cell fractionation with both native and fluorescent DnaA hybrids. We show that about 10% of cellular DnaA is reproducibly membrane-associated. This small fraction might be physiologically significant and represent the free DnaA available for initiation, rather than the vast majority bound to the datA reservoir. Using the combination of mCherry with a variety of DnaA fragments, we demonstrate that the membrane binding function is delocalized on the surface of the protein’s domain III, rather than confined to a particular sequence. We propose a new binding-bending mechanism to explain the membrane-induced nucleotide release from DnaA. This mechanism would be fundamental to the initiation of replication

Entwicklung eines Instrumentes zur Loesung grosser energiesystemanalytischer Optimierungsprobleme durch Dekomposition und verteilte Berechnung

Having only a small number of alternatives, decisions can primarily be made on a basis of experience. However, if the problems become more and more complex it is in most cases preferable to use a formal approach like methods from operations research. Systems analysis requires an integrated assessment and should model reality as 'real as possible'. Due to the huge amount of information - and hence of input data - model applications which either cannot be solved by the currently available algorithms or which require a huge amount of computer time are created easily. These applications are called large-scale systems. In order to combine the mathematical formulation of the decision problem with the necessary algorithms algebraic modeling languages have been developed. It is the objective of this thesis to develop an instrument to decompose general linear optimization problems for either a sequential or concurrent calculation (to achieve solvability at all) and to inquire if a speed-up in the process of solving can be achieved with a distributed calculation. The integration into an algebraic modeling language allows for the application of the instrument to general linear optimization problems. Using this instrument for a distributed calculation it is in principle possible to use it either in the environment of a local area network or on other computers connected by the Internet. However, our experiments revealed that distributed calculations should be avoided of linear problems when possible. The method of decomposition that is described in this paper can also be used for a further development to link different models and for decomposing non-linear problems. The use and application of the developed instrument is demonstrated in an example in the area of energy systems analysis. In this example the energy system of the Federal Republic of Germany is analyzed until the year 2050 by calculating different scenarios. (orig.)SIGLEAvailable from TIB Hannover: RO 9712(84) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The important ergot alkaloid intermediate chanoclavine-I produced in the yeast Saccharomyces cerevisiae by the combined action of EasC and EasE from Aspergillus japonicus

Background: Ergot alkaloids are a group of highly bioactive molecules produced by a number of filamentous fungi. These compounds have been intensely studied for decades, mainly due to their deleterious effects in contaminated food and feeds, but also for their beneficial pharmaceutical and agricultural applications. Biosynthesis of ergot alkaloids goes via the common intermediate chanoclavine-I, and studies of the key enzymes, EasE and EasC, involved in chanoclavine-I formation, have relied on gene complementation in fungi, whereas further characterization has been hampered by difficulties of poor EasE protein expression. In order to facilitate the study of ergot alkaloids, and eventually move towards commercial production, the early steps of the biosynthetic pathway were reconstituted in the unicellular yeast Saccharomyces cerevisiae. Results: The genomic sequence from an ergot alkaloid producer, Aspergillus japonicus, was used to predict the protein encoding sequences of the early ergot alkaloid pathway genes. These were cloned and expressed in yeast, resulting in de novo production of the common intermediate chanoclavine-I. This allowed further characterization of EasE and EasC, and we were able to demonstrate how the N-terminal ER targeting signal of EasE is crucial for activity in yeast. A putative, peroxisomal targeting signal found in EasC was shown to be nonessential. Overexpression of host genes pdi1 or ero1, associated with disulphide bond formation and the ER protein folding machinery, was shown to increase chanoclavine-I production in yeast. This was also the case when overexpressing host fad1, known to be involved in co-factor generation. Conclusions: A thorough understanding of the enzymatic steps involved in ergot alkaloid formation is essential for commercial production and exploitation of this potent compound class. We show here that EasE and EasC are both necessary and sufficient for the production of chanoclavine-I in yeast, and we provide important new information about the involvement of ER and protein folding for proper functional expression of EasE. Moreover, by reconstructing the chanoclavine-I biosynthetic pathway in yeast we demonstrate the advantage and potential of this host, not only as a convenient model system, but also as an alternative cell factory for ergot alkaloid production