In VitroSelection for Different Mutational Patterns in the HIV-1 Reverse Transcriptase Using High and Low Selective Pressure of the Nonnucleoside Reverse Transcriptase Inhibitor HBY 097

AbstractIn vitroresistance of HIV-1 against high levels of HBY 097 ((S)-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3,4-dihydro-quinoxaline-2(1H)-thione) and other quinoxaline nonnucleoside reverse transcriptase inhibitors (NNRTIs) is characterized by a specific amino acid substitution in the reverse transcriptase (RT), Gly190Glu. This change results in decreased RT polymerase activity and in reduced growth properties of the corresponding viral variant. Here we show that the appearance of the crippling mutation at codon 190 can be prevented by lowering the selective pressure exerted by HBY 097. Under low selective pressure an accumulation of other NNRTI-specific mutations is observed. Up to five NNRTI-specific substitutions were detected in some of these virus lineages. In addition, we report novel RT amino acid changes which were not observed previously, including Val106Ile, Val106Leu, and Gly190Thr. HBY 097 selects for different mutational patterns under high and low selective pressure conditions, respectively. Thus, the type of mutations which appear in HIV-infected patients undergoing therapy may be determined by the levels of the selecting drug

Production of Toxic Volatile Trimethylbismuth by the Intestinal Microbiota of Mice

The biotransformation of metals and metalloids into their volatile methylated derivatives by microbes growing under anaerobic conditions (e.g., the mammalian intestinal microbiota) plays an important role in spreading these compounds in the environment. In this paper, we could show that the presence of an intact intestinal microbiota of mice provides the conditio sine qua non for the production of these mostly toxic derivatives. To document the indispensible role of the intestinal microbiota in methylating metals and metalloids to volatile derivatives under in vivo conditions, we compared the methylation capability of conventionally raised (CONV) and germ-free (GF) B6-mice fed with chow containing colloidal bismuth subcitrate (CBS) as the starting material for the formation of volatile methylated metal(loid)s. Permethylated volatile trimethylbismuth ((CH3)3Bi) was only detected in the blood of the conventionally raised mice. Concomitantly, a higher bismuth concentration was found in organs such as liver, lung, testicles, and brain of the CONV mice as compared to those of GF mice (P > 0.01), strongly suggesting a correlation between the intestinal biomethylation of bismuth and its accumulation in mammalian tissues

Küstennahe Grundwassersysteme: Kartierung der Chloridverteilung aus Bohrdaten und Geophysik

Information on chloride (Cl) distribution in aquifers is essential for planning and management of coastal zone groundwater resources as well as for simulation and validation of density-driven groundwater models. We developed a method to derive chloride concentrations from borehole information and helicopter-borne electromagnetic (HEM) data for the coastal aquifer in the Elbe-Weser region where observed chloride and electrical conductivity data reveal that the horizontal distribution of salinity is not uniform and does not correlate with the coastline. The integrated approach uses HEM resistivity data, borehole petrography information, grain size analysis of borehole samples as well as observed chloride and electrical conductivity to estimate Cl distribution. The approch is not straightforward due to the complex nature of the geology where clay and silt are present. Possible errors and uncertainties involved at different steps of the method are discussed.Informationen zur Chloridverteilung im Grundwasserleiter sind für Planung und Management von Grundwasserressourcen in Küstengebieten sowie für die Simulation und Validierung von dichtegesteuerten Grundwassermodellen von wesentlicher Bedeutung. Es wurde eine Methode zur Ableitung der Chloridkonzentration aus Bohrungen und hubschrauber-elektromagnetischen Daten (HEM) entwickelt und für den Küstengrundwasserleiter des Elbe-Weser-Dreiecks eingesetzt. Die dort beobachteten Chloriddaten und elektrischen Leitfähigkeitsdaten zeigen eine ungleichmäßige horizontale Verteilung des Salzgehalts, die nicht mit der Küstenlinie korreliert. Der integrierte Ansatz verwendet HEM-Daten des spezifischen elektrischen Widerstands, Bohrloch-Petrographie-Informationen, Korngrößenanalysen von Bohrlochproben sowie beobachtete Chlorid- und elektrische Leitfähigkeitswerte, um die Chlorid-Verteilung abzuschätzen. Mögliche Fehler und Unsicherheiten bei den verschiedenen Schritten des Verfahrens werden diskutiert

One Gene, Many Facets: Multiple Immune Pathway Dysregulation in SOCS1 Haploinsufficiency.

BACKGROUND: Inborn errors of immunity (IEI) present with a large phenotypic spectrum of disease, which can pose diagnostic and therapeutic challenges. Suppressor of cytokine signaling 1 (SOCS1) is a key negative regulator of cytokine signaling, and has recently been associated with a novel IEI. Of patients described to date, it is apparent that SOCS1 haploinsufficiency has a pleiotropic effect in humans. OBJECTIVE: We sought to investigate whether dysregulation of immune pathways, in addition to STAT1, play a role in the broad clinical manifestations of SOCS1 haploinsufficiency. METHODS: We assessed impacts of reduced SOCS1 expression across multiple immune cell pathways utilizing patient cells and CRISPR/Cas9 edited primary human T cells. RESULTS: SOCS1 haploinsufficiency phenotypes straddled across the International Union of Immunological Societies classifications of IEI. We found that reduced SOCS1 expression led to dysregulation of multiple intracellular pathways in immune cells. STAT1 phosphorylation is enhanced, comparably with STAT1 gain-of-function mutations, and STAT3 phosphorylation is similarly reduced with concurrent reduction of Th17 cells. Furthermore, reduced SOCS1 E3 ligase function was associated with increased FAK1 in immune cells, and increased AKT and p70 ribosomal protein S6 kinase phosphorylation. We also found Toll-like receptor responses are increased in SOCS1 haploinsufficiency patients. CONCLUSIONS: SOCS1 haploinsufficiency is a pleiotropic monogenic IEI. Dysregulation of multiple immune cell pathways may explain the variable clinical phenotype associated with this new condition. Knowledge of these additional dysregulated immune pathways is important when considering the optimum management for SOCS1 haploinsufficient patients

Rise and Fall of an Anti-MUC1 Specific Antibody

So far, human antibodies with good affinity and specificity for MUC1, a transmembrane protein overexpressed on breast cancers and ovarian carcinomas, and thus a promising target for therapy, were very difficult to generate.A human scFv antibody was isolated from an immune library derived from breast cancer patients immunised with MUC1. The anti-MUC1 scFv reacted with tumour cells in more than 80% of 228 tissue sections of mamma carcinoma samples, while showing very low reactivity with a large panel of non-tumour tissues. By mutagenesis and phage display, affinity of scFvs was increased up to 500fold to 5,7×10(-10) M. Half-life in serum was improved from below 1 day to more than 4 weeks and was correlated with the dimerisation tendency of the individual scFvs. The scFv bound to T47D and MCF-7 mammalian cancer cell lines were recloned into the scFv-Fc and IgG format resulting in decrease of affinity of one binder. The IgG variants with the highest affinity were tested in mouse xenograft models using MCF-7 and OVCAR tumour cells. However, the experiments showed no significant decrease in tumour growth or increase in the survival rates. To study the reasons for the failure of the xenograft experiments, ADCC was analysed in vitro using MCF-7 and OVCAR3 target cells, revealing a low ADCC, possibly due to internalisation, as detected for MCF-7 cells.Antibody phage display starting with immune libraries and followed by affinity maturation is a powerful strategy to generate high affinity human antibodies to difficult targets, in this case shown by the creation of a highly specific antibody with subnanomolar affinity to a very small epitope consisting of four amino acids. Despite these "best in class" binding parameters, the therapeutic success of this antibody was prevented by the target biology

Groundwater Geophysics : A tool for Hydrogeology

xvi,493 hal,;ill,;20 c

Modellierung historischer Abflussverhältnisse für die Hochwasserprognose

Um historische Durchflussangaben an Flüssen, die in die Hochwasserstatistik eingehen, überprüfen und bewerten zu können, werden 1-D- und 2-D-Wasserspiegellagenberechnungen unter Verwendung historischer morphologischer Daten durchgeführt. Die Methodik sowie ihre Möglichkeiten und Grenzen werden am Beispiel der Elbe im Stadtgebiet von Dresden erläutert.Es wird deutlich, dass die notwendigen Korrekturen auch Auswirkungen auf die Hochwasserstatistik und damit auf die Schutzgrade haben

Geophysikalische Methoden zur Bewertung potenzieller Standorte für die Grundwassergewinnung

Complex geology in glacial terrain makes groundwater exploration challenging for water supply companies. Abrupt lateral changes of geological conditions, for example, raise the risk of unsuccessful exploration drilling. At some locations, local water supply companies experience a large number of dry wells, raising the need for better exploration approaches. The use of geophysical techniques enables the detection and characterization of subsurface structures in terms of aquifers and aquitards. We present two examples in which seismic and resistivity methods are combined for subsurface characterization. A thrust structure is detected in the Varde study area in Denmark and a channel structure is mapped in the Hamburg-Sülldorf study area in Germany. The different imaging characteristics of seismic P‑ and S‑waves are demonstrated. The combination of seismic and resistivity methods enables delineating groundwater-bearing and groundwater-barrier layers down to a depth of 150 m.Interreg North Sea Region ProgrammeLeibniz-Institut für Angewandte Geophysik (3464