Andreas Seyfang

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Stem cells and cancer cells maintain telomere length mostly through telomerase. Telomerase activity is high in male germ line and stem cells, but is low or absent in mature oocytes and cleavage stage embryos, and then high again in blastocysts. How early embryos reset telomere length remains poorly understood. Here, we show that oocytes actually have(More)
Recent evidence that Trypanosoma brucei synthesizes stage-regulated phosphotyrosine containing proteins and protein kinases stimulated us to assay bloodstream and insect stages of Trypanosoma cruzi and both pleomorphic and monomorphic clones of T. brucei for tyrosine phosphatase activity. Bloodstream and procyclic insect stages of T. brucei contained a(More)
Trypanosoma brucei bloodstream forms express a densely packed surface coat consisting of identical variant surface glycoprotein (VSG) molecules. This surface coat is subject to antigenic variation by sequential expression of different VSG genes and thus enables the cells to escape the mammalian host's specific immune response. VSG turnover was investigated(More)
All parasitic protozoa studied to date are incapable of purine biosynthesis and must therefore salvage purine nucleobases or nucleosides from their hosts. This salvage process is initiated by purine transporters on the parasite cell surface. We have used a mutant line (TUBA5) of Leishmania donovani that is deficient in adenosine/pyrimidine nucleoside(More)
OBJECTIVE This study analyzed a relationship between prenatal mood states and serologic evidence of immune response to Toxoplasma gondii. A secondary aim was to determine whether thyroid peroxidase autoantibody status was related to T gondii status. STUDY DESIGN Pregnant women (n = 414) were measured at 16-25 weeks' gestation with demographic and mood(More)
This paper presents a new guideline authoring tool, called Guideline Markup Tool (GMT). It proposes two useful features, which are missing in existing tools. First, it facilitates the translation of a free-text guideline into a formal representation, providing special XML macros. Second, it can be used to create links between the original guideline and its(More)
In preterm infants receiving supplemental oxygen, manual control of the inspired oxygen fraction is often time-consuming and inappropriate. We developed a system for automatic oxygen control and hypothesized that this system is more effective than routine manual oxygen control in maintaining target arterial oxygen saturation levels. We performed a(More)
Site-directed mutagenesis is a powerful tool to explore the structure-function relationship of proteins, but most traditional methods rely on the mutation of only one site at a time and efficiencies drop drastically when more than three sites are targeted simultaneously. Many applications in functional proteomics and genetic engineering, including codon(More)
Glucose transport in the bloodstream form of the protozoan parasite Trypanosoma brucei was characterized by enzymatically measuring the D-glucose uptake. Uptake kinetics showed a concentration-dependent saturable process, typical for a carrier-mediated transport system, with an apparent Km = 0.49 +/- 0.14 mM and Vmax = 252 +/- 43 cell(More)
An important application of both data abstraction and plan execution is the execution of clinical guidelines and protocols (CGP), both to validate them against a large set of test cases and to provide decision support at the point of care. CGPs can be represented and executed as a hierarchy of skeletal plans. To bridge the gap between low-level data and(More)