Individual behavior differences related to induced tumor growth in the female Syrian hamster: two studies.

The relationship of individual behavioral differences to induced tumor growth and to Natural Killer (NK) cell activity was investigated in the Syrian hamster in the context of a long-term natural stressor (group social interaction). In the first sub-experiment, 90-day-old females had blood drawn for NK cell assays. Animals were then placed in groups of ten, and two samples of behavior were obtained on videotape.

Stress-behavior interactions in hamster tumor growth.

The aim of this study was to investigate the effects of a mechanical stressor and individual behavior differences (separately and in combination) on tumor development in the female Syrian hamster. Studies by other investigators have documented the tumor-enhancing effects of such mechanical stressors as rotational stress. Previous studies by our group found that both size of tumor and time to tumor detection were significantly related to a dimension we call "activation.

Silicon-containing granules of rat liver, kidney and spleen mitochondria. Electron probe X-ray microanalysis.

Isolated rat liver mitochondria containing granule aggregates (25-75 nm in diameter) and small (5-10 nm) electron opaque granules were examined by electron probe X-ray microanalysis. The granule aggregates gave an intense Si signal, while the small granules gave both Si and P signals. Isolated mitochondria of rat liver, spleen and kidney, subjected to detergent solubilization and differential centrifugation, produced two granule fractions: (1) a 10,000 g fraction consisting predominantly of granule aggregates (25--75 nm) composed of smaller granules (5--10 nm in diameter), and (2) a 10,000--30,000 g fraction of non-aggregated small granules (5-10 nm).

Silicon in rat liver organelles: electron probe microanalysis.

Electron probe microanalysis of unfixed freeze-substituted rat liver tissue embedded in Spurr's low viscosity epoxy resin demonstrated the occurrence of Si as well as P, S, and Cl in the nucleus, nucleolus, mitochondria, and rough endoplasmic reticulum. Chemical analysis confirmed that the Si in the organelles did not originate from instrumental contaminants. This suggests that Si may be involved in the biochemistry of these subcellular organelles.

Evaluation of silicon and germanium retention in rat tissues and diatoms during cell and organelle preparation for electron probe microanalysis.

Chemical, radiochemical and x-ray microanalysis assays were used to define parameters of silicon (Si) retention during preparation og biologic samples (rat liver, spleen, kidney, lung, diatoms and cell organelles) for x-ray microanalysis, Due to its longer half-life 68-Fe was used in some cases to trace SI. Leaching of Si from cells and organelles by the aqueous preparation media was overcome by use of the freeze-substitution process. Cells were treated with 30% glycerol hypertonic sucrose medium to reduce ice damage.

Similarity in uptake and retention of trace amounts of 31 silicon and 68 germanium in rat tissues and cell organelles.

Uptake of Si and Ge (chemical analogue of Si) in rat tissues was compared to establish their subcellular localization and determine if Ge could be used to trace Si in situ. 31Si and 68Ge were found in tissues and in cell organelles after injection of 31Si (OH) 4 or 68Ge (OH) 4. Accumulation of 31Si and 68Ge in the tissues increased for 30 minutes, declined rapidly about 30 minutes and then was gradually but steadily depleted.

Utilization of model membranes in a test for the mechanism of ethylene action.

Reversible alteration of the surface tension of thin films of lipids, proteins and mixtures of both resulted when the thin films were treated with ethylene and other aliphatic gases. This effect appeared to be a nonspecific surface effect related to the molecular size of the gases. Ethylene produced no change which would ascribe to it any specific properties in this test system.

A Lack of Specificity for Ethylene-induced Mitochondrial Changes.

A critical evaluation was made of the hypothesis that the primary mode of action of ethylene in inducing physiological responses is by changing the permeability of cell organelles. The parameter investigated was the evaluation of the influence of ethylene and other gases on mitochondrial oxidation and swelling. Spectrometric evidence demonstrated that mitochondria prepared with good respiratory control can be induced to swell more rapidly with ethylene and other aliphatic gases (ethane, propene, propane, I-butene) in test solutions of 0.