| 1. |
- Björnheden, Tom, 1945, et al.
(författare)
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Computerized determination of adipocyte size.
- 2004
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Ingår i: Obesity research. - 1071-7323. ; 12:1, s. 95-105
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Fat cell size is a fundamental parameter in the study of adipose tissue metabolism, because it markedly influences the cellular rates of metabolism. Previous techniques for the sizing of adipocytes are often complicated or time-consuming. The aim of this study was to develop a new, computerized method for rapid and accurate determination of adipocyte size in a cell suspension obtained by incubating human or rat adipose tissue biopsies with collagenase. RESEARCH METHODS AND PROCEDURES: The cell suspension was placed between a siliconized glass slide and a cover slip. Using the reference method [designated as (R)], the cell diameters were determined manually using a microscope with a calibrated ocular. The new method presented here [designated as (C)] was based on computerized image analysis. RESULTS: After two well-defined corrective adjustments, measurements with (R) and (C) agreed very well. The small remaining differences seemed, in fact, to depend on inconsistencies in (R). DISCUSSION: We propose that (C) constitutes a valuable tool to study fat cell size, because this method is fast and allows the assessment of a sufficient number of cells to get reliable data on size distribution. Furthermore, images of cell preparations may be stored for future reference.
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| 2. |
- Leppanen, Olli, et al.
(författare)
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ATP depletion in macrophages in the core of advanced rabbit atherosclerotic plaques in vivo
- 2006
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Ingår i: Atherosclerosis. ; 188:2, s. 323-30
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Tidskriftsartikel (refereegranskat)abstract
- The cores of rabbit plaques in vivo are hypoxic, suggesting that ATP depletion due to an insufficient supply of oxygen and nutrients could contribute to macrophage death in atherosclerotic plaques. During hypoxia, however, macrophages maintain ATP levels by anaerobic glycolysis. To directly assess ATP and glucose metabolites in plaques in vivo, we used bioluminescence imaging to map the concentrations of ATP, glucose, glycogen, and lactate in normal and atherosclerotic rabbit aortas in vivo. Hypoxia was assessed with NITP (7-(4'-(2-nitroimidazol-1-yl)-butyl)-theophylline). Normal aortas and plaques <500 microm thick were not hypoxic and had homogenous concentrations of energy metabolites. In plaques >500 microm thick, however, the cores were characterized by ATP depletion, low concentrations of glucose and glycogen, and a high concentration of lactate. A majority of ATP-depleted macrophages within the core were viable but severely hypoxic and glucose depleted. Hyperoxia in vitro reversed the ATP depletion in macrophages in viable areas of the core. Our findings suggest that ATP depletion contributes to the death of macrophages in atherosclerotic lesions and to the formation of a necrotic core.
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