Potential tumour doubling time: determination of Tpot for various canine and feline tumours

Spontaneous tumours in dogs and cats are an excellent model for clinical human research, such as in developing proton conformation radiotherapy for humans. The kinetics of tumour cells can be used effectively to predict prognosis and response to therapy in patients with tumours. Knowledge of the kinetic parameters in these tumours is therefore important. In the present study the kinetic parameters evaluated included the labelling index (LI), relative movement (RM), mitotic index (MI), and potential doubling time (Tpot). These parameters were determined using in vivo labelling with bromodeoxyuridine, flow cytometry and histological preparation. Samples were obtained and evaluated from 72 dogs and 20 cats, presenting as patients in our clinic. Within the groups of epithelial and mesenchymal tumours from dogs and cats, the kinetic parameters LI, RM and MI were compared with Tpot. Significant correlations were observed for the comparison Tpot and LI. No correlation was found between Tpot and R

Ferromagnetic resonance of magnetite biominerals traces redox changes

Redox variations govern a multitude of key geochemical and microbiological processes within lacustrine and marine systems, yet the interpretation of these geological archives can be limited because redox-sensitive microorganisms leave behind sparse fossil evidence. Here, we assess a biologically controlled magnetic proxy through investigation of a well-constrained sedimentary record covering a perturbation of redox-conditions driven by a complete trophic cycle in Lake Constance. Ferromagnetic resonance spectroscopy of sediments reveals strong uniaxial anisotropy, indicative of single-domain magnetite particles in intact or fragmentary chain arrangements, which are an unambiguous trait of magnetotactic bacteria (MTB) and their magnetofossil remains. We show that biogenic magnetite formed intra-cellularly in MTB faithfully records changing redox-conditions at or close to the sediment water-interface. Biogenic magnetite within sedimentary records points to the proliferation of MTB parallel to a decline in water column dissolved oxygen and the formation of sulfidic surface sediments in Lake Constance associated with an episode of eutrophication (1955–1991). We conclude that magnetofossils may serve as a sensitive geological proxy to reconstruct dynamic redox-changes along the sediment-water interface and bottom waters.ISSN:0012-821XISSN:1385-013

Potential tumour doubling time: determination of Tpot for various canine and feline tumours

Spontaneous tumours in dogs and cats are an excellent model for clinical human research, such as in developing proton conformation radiotherapy for humans. The kinetics of tumour cells can be used effectively to predict prognosis and response to therapy in patients with tumours. Knowledge of the kinetic parameters in these tumours is therefore important. In the present study the kinetic parameters evaluated included the labelling index (LI), relative movement (RM), mitotic index (MI), and potential doubling time (Tpot). These parameters were determined using in vivo labelling with bromodeoxyuridine, flow cytometry and histological preparation. Samples were obtained and evaluated from 72 dogs and 20 cats, presenting as patients in our clinic. Within the groups of epithelial and mesenchymal tumours from dogs and cats, the kinetic parameters LI, RM and MI were compared with Tpot. Significant correlations were observed for the comparison Tpot and LI. No correlation was found between Tpot and R