Nico Lindemann

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A major problem for the in vitro engineering of larger tissue equivalents like those required in reconstructive surgery is the lack of solutions for sufficient nutrition and oxygenation. The starting point of our investigation was the question of whether the principles of in vitro angiogenesis can be applied and utilized for tissue engineering. A soft(More)
The vascular endothelium is a cellular interface between the blood and the interstitial space of tissue, which controls the exchange of fluid, solutes and cells by both transcellular and paracellular means. To accomplish the demands on barrier function, the regulation of the endothelium requires quick and adaptive mechanisms. This is, among others,(More)
Endothelial junctions are dynamic structures organized by multi-protein complexes that control monolayer integrity, homeostasis, inflammation, cell migration and angiogenesis. Newly developed methods for both the genetic manipulation of endothelium and microscopy permit time-lapse recordings of fluorescent proteins over long periods of time. Quantitative(More)
The in vitro development of a vascular stroma might be a solution for the engineering of vascularized tissues, however, in vitro stability of capillary-like structures is limited. In order to test the influence on maintenance of capillary-like structures, human growth hormone (hGH) was added in concentrations of 0.5, 5, 50, and 500 ng/mL in an in vitro(More)
Recent data are consistent with the presence of two 17 beta-hydroxysteroid oxidoreductase (17 beta-HOR) activities in placental homogenates. One is localized to intracellular membrane fractions. The conversion of 17 beta-estradiol (E2) to estrone (E1) by this enzyme can be completely inhibited in vitro by C19 and C21 steroids. The second activity is(More)
Hepatotoxicity occurs in animals after administration of large doses of acetaminophen and cocaine and is thought to result from production of reactive metabolites of these parent drugs by cytochrome P450. Because cimetidine binds to cytochrome P450 and inhibits hepatic drug metabolism in both humans and animals, we determined the effects of cimetidine(More)
The utilization of in vitro angiogenesis in tissue engineering might be useful in order to establish an artificial vascular network. However, it remains unclear how far the in vitro preformation of vascular structures may contribute to the perfusion of larger artificial tissue aggregates regarding the improvement of oxygenation and nutrition. In an in vitro(More)
During storage at 4 degrees C, the 17 beta-hydroxysteroid dehydrogenase activity of human placental microsomes with estradiol-17 beta was more stable than that with testosterone. In order to evaluate the basis for this difference, kinetics with C18-, C19-, and C21- steroids as substrates and/or inhibitors was studied in conjunction with an analysis of the(More)
Various naturally occurring steroids, synthetic steroid derivatives and non-steroidal hormone agonists and antagonists were assayed as inhibitors of human placental 17 beta-HSD activities. Microsomal 17 beta-HSD was inhibited by C18-, C19- and C21-steroids. Soluble 17 beta-HSD was highly specific for C18-steroids. In contrast to the soluble activity, the(More)
We have modified our radiometric assay for ethylmorphine N-demethylase to examine the metabolism of codeine. We find that the current assay gives excellent separation of metabolites with a zero time activity of 0.08%. The N- and O-demethylations are linear for up to 30 min with up to 1 mg/ml of microsomal protein. The pH profiles show slightly different(More)