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Biofilm-derived Planktonic Cell Yield: A Mechanism for Bacterial ProliferationBester, Elanna 14 February 2011 (has links)
The development of biofilms at solid-liquid interfaces has been investigated extensively, whereas the yield of planktonic cells from biofilms has received comparatively little attention. The detachment of single cells from biofilms has been attributed mainly to the erosive action of flowing liquid or the dispersal of cells from within biofilm microcolonies. The result has been an underestimation of the active role that biofilms can play in microbial proliferation through the production and release of planktonic cells to the environment.
In this study, the cultivation of Pseudomonas sp. strain CT07 biofilms in conventional flowcells, glass tubes and a novel CO2 evolution measurement system was utilized to show that biofilm-derived planktonic cell yield was initiated within 6 hours of initial surface colonization and increased in conjunction with biofilm development. The magnitude of the yield was influenced by the metabolic activity of the biofilm, which was in turn dependent on environmental conditions, such as carbon availability. The physiologically active region of the biofilm was responsible for the yield of significant numbers of planktonic cells (~107 CFU.cm-2.h-1), whereas a less active biofilm zone was optimized for survival during unfavourable conditions and shown to be responsible for the subsequent re-establishment of biofilm structure, activity and cell yield. Despite the yield of numerically considerable numbers of planktonic cells (~1010 CFU), a carbon balance revealed that the carbon investment required to maintain this yield was insignificant (~1%) compared to the amount of carbon channelled into CO2 production (~54%). Together, these results indicate that biofilm-derived planktonic cell yield represents an efficient proliferation mechanism and support the view that the biofilm lifestyle affords microbes a dual survival-proliferation strategy, where the dominant strategy depends on the prevailing environmental conditions. An alternative model of biofilm development is presented to account for planktonic cell yield during all stages of biofilm development.
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Staufen Regulates Eye DevelopmentCockburn, Diane M. 06 December 2011 (has links)
Despite their undisputed importance to embryonic growth, the role of mRNA transport proteins in the developing visual system has been widely uncharacterized. Through RNA interference, this study aims to discover the function of Staufen 2 (Stau2), an mRNA transport protein, in chick eye development. When Stau2-miRNA was electroporated into the E1.5 primary optic vesicle, two days later they exhibited a reduction of eye size by 47%, whereas control miRNA did not significantly change eye size. TUNEL, β-III tubulin and BrdU staining were used to analyze the retinal apoptotic, differentiation and proliferative levels respectively, in response to Stau2 knockdown. These data suggest that the small eye is a result of a decrease in proliferation, and not cell death or pre-mature differentiation. Rescue experiments were done with each of the three Stau2 isoforms and confirmed both the direct effect of Stau2-miRNA and the involvement of these isoforms in eye development.
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Immunhistochemische Analyse von Haut- und Nierenbiopsien bei der ANCA-assoziierten Vaskulitis am Beispiel der Wegener'schen Granulomatose : eine Untersuchung zur Beurteilung von Proliferation und Apoptose /Wilke, Susanne. January 2005 (has links)
Zugl.: Berlin, Charité, University-Med., Diss., 2005.
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The chemistry and in vitro cytotoxicity study of manganese oxide nanostructuresChan, Yiu-ming, January 2007 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available in print.
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Hairy and enhancer of split 1 (Hes1) and Krüppel-like factor 4 (K1f4) in enteric neural crest cellSit, Yu-lam, Francesco. January 2007 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available in print.
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Die Retinogenese im dreidimensionalen Zellkultursystem des Huhns eine zell- und molekularbiologische Studie neurotropher Funktionen der Zytokine GDNF, BDNF und PEDF /Eberhardt, Katja. Unknown Date (has links) (PDF)
Darmstadt, Techn. Universiẗat, Diss., 2007.
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Olfactory ensheathing glia : an investigation of factors affecting responsiveness of these cells in vitro and in vivo /De Mello, Thalles R. B. January 2006 (has links)
Thesis (Ph.D.)--University of Western Australia, 2006.
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Rapamycin verhindert das Remodeling pulmonaler Gefässe in chronisch hypoxischen Mäusen /Stieger, Philipp. January 2007 (has links)
Zugl.: Giessen, Universiẗat, Diss., 2007.
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The N-terminal domain of the Y-box binding protein YB-1 plays a major role in cell proliferation and apoptosisKhandelwal, Payal, January 2008 (has links) (PDF)
Thesis (Ph.D.)--University of Tennessee Health Science Center, 2008. / Title from title page screen (viewed on July, 31, 2008). Research advisor: Ramareddy V. Guntaka, Ph.D. Document formatted into pages (xiii, 111 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 90-111).
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Der Effekt von Sirolimus auf die reaktive Zellproliferation und Apoptose in einem humanen ex vivo Restenose-ModellZellmann, Svenja, January 2007 (has links)
Ulm, Univ., Diss., 2007.
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