The use of double Formvar film to support paraffin sections for light microscopy and subsequent STEM/X-ray microanalysis.
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Adenocarcinoma↗
Biomedical subjects
J Halgunset
Publications and source records attributed to J Halgunset.
Butyrate effects on growth, morphology, and fibronectin production in PC-3 prostatic carcinoma cells.
Sodium butyrate (NaBT) induces differentiation in several transformed cell lines. The present paper describes the effects of NaBT on some transformation-associated parameters in PC-3, a human prostatic carcinoma cell line. NaBT produces a reversible inhibition of cell proliferation, but anchorage-independent growth is more sensitive than monolayer growth. Soft agarose colonies are reduced by over 50% at 0.1 mM, a concentration that hardly affects growth on solid substrata. Monolayer cells respond to NaBT by spreading and flattening, as demonstrated by a combined light and electron microscopic, morphometric technique. After 4 days' exposure to 2 mM NaBT, the average cell covers an area of substratum that is approximately double that covered by control cells. The average cell volume, however, remains unchanged. This flattening is paralleled by an increase in the number of stress fibers, as seen by fluorescence microscopy. Only minor changes are observed in the microtubule and intermediate filament patterns. While control cells contain very little antifibronectin reactive material, substantial amounts of such material appear upon NaBT treatment. The amount of fibronectin increases up to 100-fold in cells exposed to NaBT. The changes observed correspond to a suppression of properties that are generally associated with the malignant phenotype.
Actin Cytoskeleton↗
Light microscopic morphometric analysis of castration effects in the different lobes of the rat prostate.
The morphologic effects of androgen deprivation in the different lobes of the rat prostate were examined by light microscopic morphometry. The prostates of Wistar male rats (260-340 g) were fixed in situ by glutaraldehyde perfusion in castrated animals 1 week after gonadectomy and in intact animals. The ventral (VP), dorsal (DP), and lateral (LP) lobes as well as the coagulating gland (CG) were dissected out, weighed, and processed for light microscopy. Using stereologic methods the following parameters were estimated for each lobe: volume fraction of connective tissue, epithelium and glandular lumina, average epithelial height, average epithelial cell volume, and total number of epithelial cells. Castration leads to a 58-76% reduction of the wet weight of all prostatic lobes. The decrease of glandular tissue is greater in VP than in LP, DP, and CG. In VP and LP, there is a 39-45% reduction of the epithelial height, and this effect is less pronounced in DP and CG. For all lobes, the shrinkage of average epithelial cell volume is in the same range (25-30%). Moreover, in VP and LP, there is a 70% reduction of the total number of cells, whereas the reduction is less in DP and CG. It thus seems that the reduction of prostatic epithelial tissue mass upon castration is due to a reduction of the number of cells as well as a reduction of the volume of individual cells. VP and LP appear to be more androgen-dependent than DP and CG.
Animals↗
Quick sampling and perpendicular cryosectioning of cell monolayers for the X-ray microanalysis of diffusible elements.
A quick sampling and preparation method for freezing of cell monolayers is described. The cells are grown on a large Formvar film supported by a frame of polystyrene. A polyvinylpyrrolidone (PVP) solution is applied to one side of the film forming a flat disc when frozen with a pair of pliers precooled in liquid nitrogen. The PVP solution provides the specimen with sufficient strength and may be used as an elemental standard for absolute quantification if salts of known concentrations are added. Manipulation of the cells prior to freezing is thus restricted to a minimum, which eliminates possible harmful treatments like scraping and centrifugation. The procedure is quickly performed, the freezing being completed within 30 s of the cells having been removed from the culture well. The analytical results reveal low and stable Na:K ratios. Our results confirm that cells in vitro are comparable to cells in vivo with respect to elemental composition.
Adenocarcinoma↗
Toxicity of n-C9 to n-C13 alkanes in the rat on short term inhalation.
Male Sprague Dawley rats were exposed to inhalation of n-C9 to n-C13 alkanes close to air saturation at 20 degrees (4438, 1369, 442, 142 and 41 p.p.m., respectively) for 8 hours and observed for the following 14 days. In addition, exposure to higher and lower concentrations of n-C9 was performed. The concentration of alkane in the brain after exposure exceeded that of blood for the lower alkanes, while the higher alkanes possessed a brain/blood ratio equal to or less than unity. Gross ataxia, general and focal seizure and spasms were observed in animals exposed to n-C9 in the range from 5280 to 3560 p.p.m. No toxic effects were observed in animals exposed to 2414 p.p.m. of n-C9 or to the other alkanes. An LC50 value for n-C9 of 4467 +/- 189 p.p.m. was estimated. Despite the clinical improvement in animals surviving the n-C9 exposure of 4438 p.p.m. (6/10), severe cerebellar damages were found at autopsy at the end of the observation period, with a loss of Purkinje cells as the most prominent feature. Immediate post mortem examination (4/10) showed marked vascular congestion of the liver as well as slight fatty degeneration but no cerebellar damage. No abnormalities were observed in animals exposed to the other alkanes. The significant distribution in the brain of the n-C9 alkane, the clinical signs of cerebellar dysfunction and the damage of cerebellar neurons would suggest CNS to be a possible target organ for the toxic effects of the n-C9 alkane.
Administration, Inhalation↗
Subcellular concentrations of calcium, zinc, and magnesium in benign nodular hyperplasia of the human prostate: X-ray microanalysis of freeze-dried cryosections.
Biopsies from human prostates were obtained from normal and hyperplastic glands. The intracellular concentrations of calcium, zinc, and magnesium were analyzed using X-ray microanalysis of freeze-dried cryosections. Two prostate biopsies were obtained from kidney donors, ages 19 and 50 years, without any sign of benign nodular hyperplasia. The normal tissues were frozen within 15 min after circulatory arrest. The central part of biopsies from eight elderly men suffering from benign nodular hyperplasia were frozen within 30 s after excision. Adjacent tissue was processed for light microscopy and histopathological diagnosis. All samples were fresh-frozen using liquid nitrogen cooled pliers, without the use of any freeze-protection, fixation, or staining. In both the normal and the hyperplastic prostates high concentrations (up to above 100 mmol/kg dry weight) of zinc were present in electron dense bodies in the cytoplasm of the epithelial cells. Together with zinc, about equal concentrations of magnesium were found. Calcium was detected in 4 to 8 times the concentration of zinc. Significant, positive correlation between calcium and zinc as well as between calcium and magnesium in the cytoplasm was a typical finding in both normal and hyperplastic glands. In six of eight patients, older than 60 years of age, high levels of calcium (17.0-38.8 mmol/kg dry weight) were observed in the nuclei of the epithelial cells, while very low values were found in the remaining two. In the two younger cases (19 and 50 years of age), the nuclear calcium level in prostatic epithelium was relatively low (about 10 mmol/kg dry weight). These observations suggest that an increase of intranuclear calcium with advancing age may be of pathogenetic significance to growth disturbances in the prostate.
Adult↗
Retinoic acid (RA): an inhibitor of 5 alpha-reductase in human prostatic cancer cells.
The effect of retinoic acid (RA) on testosterone metabolism was examined in a prostatic cancer cell line of human origin, PC-3. In cells growing as monolayers as well as in cell homogenates RA causes a dose-dependent inhibition of the 5 alpha-reductase activity, thus preventing the conversion of testosterone into its hormonally active metabolite, dihydrotestosterone. Fifty per cent inhibition of the enzyme activity occurred at an RA concentration of 2 x 10(-5)M. The pattern of inhibition was that of a non-competitive inhibitor. However, when incubations were performed in the presence of varying amounts of NADPH, it turned out that RA exerts its effect by competitive inhibition of the cofactor action. Although the severe toxicity of RA precludes its systemic use as a 5 alpha-reductase inhibitory drug in humans, the possible anti-androgenic effect of other, less toxic, retinoids should be investigated.
5-alpha Reductase Inhibitors↗
Short-term effects of radiographic contrast media on monolayer cell cultures and hepatocytes.
Short-term effects of nine different contrast media, saline, sucrose, and mannitol on monolayer cell cultures and isolated rat hepatocytes were studied. Conventional high osmolal ionic contrast media (Na-metrizoate, Na-iothalamate, meglumine/Na-diatrizoate, meglumine-calcium-metrizoate) and the new, low-osmolal, nonionic (metrizamide, iopamidol, iohexol) and ionic dimer (meglumine/Na-ioxaglate) were tested. Dilutions of different contrast media at the same final osmolality produced similar effects on cultured cells and on isolated hepatocytes as assessed by the leakage of cytoplasmic lactate-dehydrogenase. This short-term toxicity seemed to be a function of the osmolality and of the exposure time. The effect of saline, sucrose, and mannitol was equal to that of contrast media at the same osmolality.
Animals↗
Cytostatic effects of radiographic contrast media in synchronized cell cultures.
The cytostatic effects of conventional high osmolal ionic contrast media (meglumine-calcium metrizoate and Na-metrizoate) and new low osmolal nonionic contrast media (iohexol and iopamidol) in synchronized cell cultures were tested. The cell-cycle prolongation was most pronounced when the contrast media were added in the G1 phase, but there was also a marked effect when the contrast media were added in the S phase or late in the G2 phase. The cytostatic effect even persisted into the first cell cycle following the termination of the exposure. All four contrast media exerted effects stronger than that of equiosmolal saline. Iohexol and iopamidol produced a more severe effect than meglumine-calcium metrizoate and Nametrizoate at equal osmolality. Thus, the cytostatic effect of contrast media cannot be explained only by hypertonicity; the contrast media must have an additional specific cytostatic effect. When the cytostatic effect was related to iodine concentration, the new low osmolal nonionic contrast media influenced the cell cycle less than the conventional high osmolal ionic contrast media.
Cell Cycle↗
[Myocarditis as a cause of sudden death in children and young adults].
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Adolescent↗
Effects of radiographic contrast media on monolayer cell cultures.
The relationship between iodine concentration, osmolality, and toxicity for nine different contrast media was studied. High osmolal conventional ionic contrast media (Na-metrizoate, Na-iothalamate, meglumine/Na-diatrizoate, meglumine-calcium-metrizoate) and the new low osmolal nonionic (Metrizamide, iopamidol, iohexol) and ionic dimer (Meglumine/Na-ioxaglate) contrast media were tested. Monolayer cell cultures of human cervical carcinoma in situ cells were used as a test system. The toxicity of contrast media on cell cultures was strongly dependent on the osmolality, and different contrast media with the same osmolality had about similar effects on the cell cultures. However, contrast media seem to have some additional and more specific effects since equiosmolal saline and mannitol were better tolerated. When the toxicity was related solely to iodine concentration it emerged that the new low osmolal contrast media were much better tolerated than the high osmolal conventional contrast media.
Carcinoma in Situ↗
[Analytic electron microscopy. A research method used in diagnosis].
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Aged↗
Stereological estimation of average cell volume in monolayer culture by combined light and electron microscopy.
In order to convert stereological ratio estimates into 'absolute' values ('per cell' values) the average cell volume must be estimated. The present paper describes a stereological method based on well-known point counting procedures for the estimation of average cell volumes in monolayer cultures fixed in situ. This method involves estimation of the average attachment area per cell by light microscopy combined with estimation of the attachment membrane surface density by electron microscopy. There is no need for any assumption as to cellular or nuclear shape. The method has been tested on an established cell line, NHIK 3025, and shows a good accuracy. It has also been used to analyse the volume changes that take place in human monocytes during monolayer culture, demonstrating a 28-fold increase of the average cell volume over 10 days.
Carcinoma↗
Human monocyte mediated cytotoxicity to K-562 cells: a freeze-fracture-, scanning- and thin section electron microscopic study.
The structural features of "natural"human monocyte-mediated cytotoxicity towards K-562 leukemia cells in vitro have been examined. Human monocytes bound K-562 cells firmly and mediated a slow cytolysis of the leukemia cells. Monocyte binding of target cells was shown to be trypsin sensitive. Freeze-fracture and thin section electron microscopy revealed that effector and target cells were separated by a irregular space larger than 20 nm. There was no evidence for the involvement of specialized membrane junctions or organelle transfer between monocytes and target cells. Scanning electron microscopy revealed that K-562 cells bound to monocytes progressively lost their microvilli. This process started in the membrane areas close to the effector-target cell interaction. The results suggest that binding of target cells by monocytes followed by action of short-range soluble cytotoxic mediators may be the mechanism for the monocyte-mediated cytotoxicity towards K-562 cells.
Animals↗
Effects on the ATP content of cultured cells after radiographic contrast media exposure. Evidence for accumulation of contrast media in cultured cells.
The ATP content of cultured cells after exposure to meglumine-calcium metrizoate, sodium metrizoate, iohexol, iopamidol and saline was studied. Initially, the ATP content diminished rapidly for a short period and thereafter slowly during the incubation. After incubation with contrast media or saline, the ATP content slowly increased to normal when the cells were reincubated with fresh nutrient medium. Different contrast media and saline with the same final osmolality produced a similar effect on the ATP content of the cultured cells. Cellular association of meglumine-sodium diatrizoate, sodium metrizoate, sodium-iothalamate, iohexol and iopamidol was also examined. The established cell line NHIK 3025 as well as primary cultures of human umbilical endothelium were found to accumulate contrast media in a time- and concentration-dependent manner. When the incubation was carried out at 4 degrees C, the cellular accumulation of contrast medium was less than 35 per cent of that seen at 37 degrees C. It therefore seems that energy-dependent processes are involved to some degree.
Adenosine Triphosphate↗