Karl Decker

Bio: Karl Decker is an academic researcher from University of Freiburg. The author has contributed to research in topics: Tumor necrosis factor alpha & Kupffer cell. The author has an hindex of 50, co-authored 220 publications receiving 12411 citations. Previous affiliations of Karl Decker include National Academy of Sciences of Ukraine.

Energy conservation in chemotrophic anaerobic bacteria.

Abstract: [This corrects the article on p. 100 in vol. 41.].

Biologically active products of stimulated liver macrophages (Kupffer cells)

Abstract: Macrophages belong to the mononuclear phagocyte system that includes the blood monocytes and the various kinds of mobile and sessile macrophages They are recruited from the stem cells of the bone marrow and differentiate under the influence of specific signals [1] [e g the macrophage colonystimulating factor, the granulocyte/macrophage colonystimulating factor and interleukin-3 (IL-3)] via several intermediary stages to mature macrophages [2] (Fig 1) They belong, together with the highly specific immune system, to the body’s defensive machinery Although all macrophages are ultimately derived from the same source (bone marrow) they may in some instances, e g in the liver, also propagate at the site of their final destination [3] Topological factors seem to influence their final differentiation and to endow each type with particular metabolic and structural features One can clearly recognize specific capabilities in the mobile bloodborne macrophages (monocytes), in the individually moving but sequestered (peritoneal and alveolar) macrophages, and in the various sessile tissue macrophages such as those residing in bone marrow, spleen, brain, skin and liver [4,5]

The contraction of hepatic stellate (Ito) cells stimulated with vasoactive substances : possible involvement of endothelin 1 and nitric oxide in the regulation of the sinusoidal tonus

Abstract: We have studied the contractility of liver sinusoidal stellate (Ito) cells stimulated with endothelin 1, nitric-oxide donors and eicosanoids. Contraction and relaxation of stellate cells were detected by the use of a silicone-rubber method that revealed the traction forces exerted by these cells. Endothelin 1 was a strong elicitor for stellate-cell contraction. 78, 55, 59 and 56% of stellate cells were contracted 2.5, 5, 10 and 20 min, respectively, after exposure to 10 nM endothelin 1. The effect of endothelin 1 was dose dependent and still detectable at an endothelin 1 concentration of 100 pM. Concomitantly, an endothelin-dependent formation of inositol phosphates was apparent; values of InsP, InsP2, and InsP3 were 881 +/- 99%, 1965 +/- 368%, and 791 +/- 120% of control, respectively, 20 min after addition of 10 nM endothelin 1. In addition, endothelin 1 caused a transient increase of [Ca2+]i in stellate cells from a basal value of 121 +/- 9 nM to maximal 1015 +/- 86 nM. These endothelin-1 effects were much stronger than those of the thromboxane-A2 analogue U46619 and of prostaglandin F2 alpha. In contrast, Iloprost, prostaglandin E2, and sodium nitroprusside promoted stellate-cell relaxation; for example, 82, 83 and 71% of stellate cells relaxed 5, 10, and 20 min, respectively, after addition of 500 microM sodium nitroprusside to contacted cells. Prostaglandin E2 and Iloprost led to elevation of cAMP levels in stellate cells from a basal value of 9.2 +/- 0.8 pmol/well to 55.1 +/- 8.0 and 122.2 +/- 12.2 pmol/well 10 min after addition of prostaglandin E2 (5 microM) and Iloprost (5 microM), respectively, in the presence of 3-isobutyl-1-methylxanthine (0.5 mM). However, sodium nitroprusside was a trigger for cGMP accumulation. Intracellular cGMP increased from a basal value of 0.9 +/- 0.07 pmol/well to 13.4 +/- 6.7 pmol/well 10 min after addition of 500 microM sodium nitroprusside into the medium. It is interesting that Iloprost and sodium nitroprusside also induced the disappearance of actin stress fibers in contracted cells; F-actin stress fibers became less numerous and de-aggregated; more than 90% of stellate cells were void of stress fibers after 10 microM Iloprost treatment for 30 min. Thus, endothelin 1, eicosanoids and sodium nitroprusside are able to modulate the contractility of stellate cells.(ABSTRACT TRUNCATED AT 400 WORDS)

The NOX Family of ROS-Generating NADPH Oxidases: Physiology and Pathophysiology

Abstract: For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phag...

Microbial Fuel Cells: Methodology and Technology†

Abstract: Microbial fuel cell (MFC) research is a rapidly evolving field that lacks established terminology and methods for the analysis of system performance. This makes it difficult for researchers to compare devices on an equivalent basis. The construction and analysis of MFCs requires knowledge of different scientific and engineering fields, ranging from microbiology and electrochemistry to materials and environmental engineering. Describing MFC systems therefore involves an understanding of these different scientific and engineering principles. In this paper, we provide a review of the different materials and methods used to construct MFCs, techniques used to analyze system performance, and recommendations on what information to include in MFC studies and the most useful ways to present results.

Host-Bacterial Mutualism in the Human Intestine

Abstract: The distal human intestine represents an anaerobic bioreactor programmed with an enormous population of bacteria, dominated by relatively few divisions that are highly diverse at the strain/subspecies level. This microbiota and its collective genomes (microbiome) provide us with genetic and metabolic attributes we have not been required to evolve on our own, including the ability to harvest otherwise inaccessible nutrients. New studies are revealing how the gut microbiota has coevolved with us and how it manipulates and complements our biology in ways that are mutually beneficial. We are also starting to understand how certain keystone members of the microbiota operate to maintain the stability and functional adaptability of this microbial organ.

Energy conservation in chemotrophic anaerobic bacteria.

Abstract: [This corrects the article on p. 100 in vol. 41.].