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T Funke

Publications and source records attributed to T Funke.

11 recordsLinked to original sources
PubMed2005

CR-EST: a resource for crop ESTs.

The crop expressed sequence tag database, CR-EST (http://pgrc.ipk-gatersleben.de/cr-est/), is a publicly available online resource providing access to sequence, classification, clustering and annotation data of crop EST projects. CR-EST currently holds more than 200,000 sequences derived from 41 cDNA libraries of four species: barley, wheat, pea and potato. The barley section comprises approximately one-third of all publicly available ESTs. CR-EST deploys an automatic EST preparation pipeline that includes the identification of chimeric clones in order to transparently display the data quality. Sequences are clustered in species-specific projects to currently generate a non-redundant set of approximately 22,600 consensus sequences and approximately 17,200 singletons, which form the basis of the provided set of unigenes. A web application allows the user to compute BLAST alignments of query sequences against the CR-EST database, query data from Gene Ontology and metabolic pathway annotations and query sequence similarities from stored BLAST results. CR-EST also features interactive JAVA-based tools, allowing the visualization of open reading frames and the explorative analysis of Gene Ontology mappings applied to ESTs.

Crops, Agricultural↗
PubMed1990

The singularly perturbed Hodgkin-Huxley equations as a tool for the analysis of repetitive nerve activity.

A qualitative analysis of the Hodgkin-Huxley model (Hodgkin and Huxley 1952), which closely mimics the ionic processes at a real nerve membrane, is performed by means of a singular perturbation theory. This was achieved by introducing a perturbation parameter that, if decreased, "speeds up" the fast variables of the Hodgkin-Huxley equations (membrane potential and sodium activation), whereas it does not affect the slow variables (sodium inactivation and potassium activation). In the most extreme case, if the perturbation parameter is set to zero, the original four-dimensional system "degenerates" to a system with only two differential equations. This degenerate system is easier to analyze and much more intuitive than the original Hodgkin-Huxley equations. It shows, like the original model, an infinite train of action potentials if stimulated by an input current in a suitable range. Additionally, explanations for the increased sensitivity to depolarizing current steps that precedes an action potential can be found by analysis of the degenerate system. Using the theory of Mishchenko and Rozov (1980) it is shown that the degenerate system does not only represent a simplification of the original Hodgkin-Huxley equations but also gives a valid approximation of the original model at least for stimulating currents that are constant within a suitable range.

Action Potentials↗
PubMed1989

[The pharmacology of the lipoxygenase inhibitors oxphaman (1-(2,5-dihydroxybenzylidene)aminoadamantane) and oxphalin (1-(3,4-dihydroxybenzylidene)-2,4,6-trimethylaniline].

Oxphaman and particularly oxphalin, among other phenolic azomethines, have been proven as strong inhibitors of lipoxygenases (LOX) from reticulocytes, soybean, thrombocytes as well as of quasi-LOX (hemoglobin) with IC50 values which correspond with those of known LOX inhibitors. The 5-LOX is likewise strongly, the cyclooxygenase of sheep seminal vesicles only weakly inhibited. Nevertheless, antiinflammatory effectivity was found in some carrageenin-induced inflammatory models of the rat as well as in the arachidonic acid- and croton oil-induced ear oedema of the mouse. Adjuvant arthritis, experimental pain, skin permeability and allergy models (anaphylactic paw oedema, cutaneous anaphylaxis, asthma, picryl chloride ear oedema) were not, only weakly or irregularly influenced. In the guinea pig ileum a certain antihistaminic, anticholinergic and leukotriene antagonistic activity was found. An inflammation-induced vasodepression (anaphylactic shock, dextran paw oedema. UV irradiation) was dose-dependently prevented or even reversed, obviously on the basis of oxygen radical scavenging.

Adamantane↗
PubMed1988

Action of metal chelators on lipoxygenases, cyclooxygenase and on inflammation-induced vasodepression.

Metal complexing agents could exert antiinflammatory activity by inhibition of oxygen radical production, by inhibition of eicosanoid synthesis and by inhibition of metalloenzymes. We found a moderate antiedema activity of the iron (II)/iron (III)-chelator combination, o-phenanthroline/desferrioxamine, which could refer to an involvement of iron ions in the inflammatory reaction. The newly synthetized complexing agent ethylene-diimino-dibutyric acid caused weak antiedema and antivasodepressor effects which remain to be explained. Altogether, the in vivo effects of the metal chelators were rather weak. In vitro, only desferrioxamine produced a remarkable inhibition of two lipoxygenases.

Animals↗
PubMed1988

Role of eicosanoids in inflammatory reactions of rats.

Nonsteroidal antiinflammatory agents of several subgroups, regarding eicosanoid-producing enzyme inhibition, have been tested in vitro and in vivo. There was no overt correlation between cyclooxygenase and/or lipoxygenase inhibition in vitro and antiinflammatory effects. It is possible that eicosanoids do not play a key role as inflammatory mediators, i.e. that the course of the life-protecting inflammatory reaction is ensured by an ensemble of mediators, cellular events and further mechanisms of the whole living organism.

Animals↗
PubMed1985

Dialysis-induced cardiac arrhythmias: fact or fiction? Importance of preexisting cardiac disease in the induction of arrhythmias during renal replacement therapy.

Frequency and grade of premature ventricular depolarizations were assessed in 10 patients on maintenance renal replacement therapy. All medication was withdrawn prior to the study. Each patient was treated sequentially by 8 different methods [acetate and bicarbonate hemodialysis (HD), hemofiltration, hemodiafiltration, ultrafiltration, use of 5 different membranes]. Despite marked changes in serum electrolyte concentrations there was no difference in frequency or grade of premature ventricular beats between the periods before, during, and after renal replacement therapy. Comparison of the 8 methods tested revealed no superiority of 1 method during the observation period of 192 h for each patient. In a second group of 8 patients with confirmed coronary artery disease, acetate HD had no effect on grade and frequency of ventricular arrhythmias, although arrhythmias occurred more often (p less than 0.05) and were more dangerous. We therefore conclude that the incidence of ventricular arrhythmias is primarily dependant on the presence of preexisting coronary artery disease and that HD or related methods do not increase the risk of ventricular ectopies in patients without digitalis medication.

Adult↗