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Biomedical subjects

G Bennett

Publications and source records attributed to G Bennett.

At least 145 records · Page 8Linked to original sources
PubMed1979

Comparison of droperidol, haloperidol and prochlorperazine as postoperative anti-emetics.

The results of this study demonstrate that prochlorperazine, haloperidol and droperidol are all effective post-operative anti-emetic compounds when compared to saline but vary in onset of activity and duration of action. Haloperidol has the shortest onset of action, being effective within 30 minutes of intravenous administration. Prochlorperazine has an intermediate onset of action and droperidol is the slowest of the three compounds but the only one to provide significant anti-emesis 4-24 hours following administration. Our data suggest that a combination of haloperidol and droperidol may be more effective as an anti-emetic than any one of the compounds used alone.

Droperidol↗
PubMed1978

Synthesis and migration of glycoproteins in cells of the rat thymus, as shown by radioautography after 3H-fucose injection.

Young male rats received a single intravenous injection of 3H-fucose and were killed after various time-intervals. Light- and electron-microscopic radioautographic studies of the thymus in animals killed shortly after injection showed that all of the different cell types present incorporated 3H-fucose label. The heaviest uptake occurred in macrophages and in hypertrophic epithelial cells located near the cortico-medullary border. Somewhat lighter incorporation was observed in medullary and cortical stellate epithelial cells and in cells designated as special cells, while the lightest reaction appeared over lymphocytes. In all cells the label was localized initially to the Golgi apparatus, where, presumably, it was incorporated into glycoproteins. With time, some of the labeled putative glycoproteins in all cell types migrated to the plasma membrane. In macrophages, much of the label migrated to lysosomal bodies, while in the special cells the label migrated to dense bodies which may also be of lysosomal nature. In stellate and hypertrophic epithelial cells much of the label migrated to characteristic vacuoles. The possible relationship between the observed glycoprotein synthesis in these cells and hormone production is discussed.

Animals↗
PubMed1977

Formation and turnover of plasma membrane glycoproteins in kidney tubules of young rats and adult mice, as shown by radioautography after an injection of 3H-fucose.

The formation and turnover of the glycoproteins of the plasma membrane have been investigated by quantitative radioautography in the kidney tubules of young rats and adult mice killed at various time intervals after an intravenous injection of 3H-fucose. In young (40 g) rats killed five to ten minutes after the injection, radioautographs of distal tubule cells show that the Golgi apparatus contained about 85% of the cell label. By 30 hours, only 8% of the label remained in this organnele, whereas 67% was in the plasma membrane, indicating that most of the label had migrated from Golgi apparatus to this membrane. Similarly, in proximal tubule cells, about 82% of the label was initially in the Golgi apparatus, but less than 2% remained at 30 hours, at which time 78% was in the plasma membrane. In the latter cells, the apical tubules and vacuoles became heavily labeled before the apical microvilli did and, therefore, may be involved in the transit of label from the Golgi apparatus to the microvillous membrane. The results are interpreted to mean that, in kidney tubule cells, the Golgi apparatus is the site of a continuous incorporation of fucose into glycoproteins and that these migrate to the plasma membrane. In fully formed cells, such a conclusion would imply a continuous turnover of plasma membrane glycoproteins. However, in the rapidly growing kidney of young rats many new cells are added daily, the growth of which might involve net addition as well as turnover of glycoproteins. Accordingly, the experiment has been repeated in adult mice, in which the cells are assumed to be fully formed. Furthermore, since turnover implies eventual decrease of incorporated label, some of the animals have been killed at longer intervals, up to 27 days after injection. In these adult mice, as in young rats, prompt Golgi uptake and subsequent migration of label to the plasma membrane were observed in distal and proximal tubules cells. With time the label content of the plasma membrane decreased gradually, and by 27 days had virtually disappeared. From grain counts, it is concluded that the mean half-life of glycoproteins in the apical membrane of distal tubule cells is about two days, whereas in both the apical and basal membranes of proximal tubule cells, it is slightly over three days.

Age Factors↗
PubMed1977

Secondary liposarcoma of the ovary.

This report is the first description of a secondary ovarian liposarcoma. The primary growth was in the mediastinum. The growth rate of the ovarian tumor was very rapid, but the patient died of cardiopulmonary causes. The mode of spread is discussed, and it probably occurred by transcelomic migration and surface implantation.

Adult↗
PubMed1977

A non-chromatographic radioimmunoassay of testosterone in serum.

Convenient methodology based on separation of testosterone from non-alcoholic neutral steroids by means of a sulfation procedure has been developed for the radioimmunoassay (RIA) of testosterone in male and in female serum. When coordinated with our previously published non-chromatographic procedure (1) for the RIA of estrone and 17 beta-estradiol in serum all 3 steroids can be determined in the same specimen. With only minor modification (14) progesterone also can be determined. Validation of the procedure was based on: 1. agreement between results obtained using TLC and sulfation to fractionate testosterone (r=0.99; b=1.03), 2. accurate recovery of different quatities of testosterone added to serum, 3. independence of the concentration of testosterone and volume of serum used for assay, 4. low procedural blanks (1.1+/-0.7 pg), 5. low intra-assay (4.7-4.8%) and interassay (4.8-8.8%) variability and 6. correspondence of observed values for testosterone in male serum (7.00+/-2.03 ng/ml) and in femal serum (420+/-115 pg/ml) with those reported previously by others.

Animals↗
PubMed1974

Migration of glycoprotein from the Golgi apparatus to the surface of various cell types as shown by radioautography after labelled fucose injection into rats.

A single intravenous injection of L-[(3)H]fucose, a specific glycoprotein precursor, was given to young 35-45 g rats which were sacrificed at times varying between 2 min and 30 h later. Radioautography of over 50 cell types, including renewing and nonrenewing cells, was carried out for light and electron microscope study. At early time intervals (2-10 min after injection), light microscope radioautography showed a reaction over nearly all cells investigated in the form of a discrete clump of silver grains over the Golgi region. This reaction varied in intensity and duration from cell type to cell type. Electron microscope radioautographs of duodenal villus columnar cells and kidney proximal and distal tubule cells at early time intervals revealed that the silver grains were restricted to Golgi saccules. These observations are interpreted to mean that glycoproteins undergoing synthesis incorporate fucose in the saccules of the Golgi apparatus. Since fucose occurs as a terminal residue in the carbohydrate side chains of glycoproteins, the Golgi saccules would be the site of completion of synthesis of these side chains. At later time intervals, light and electron microscope radioautography demonstrated a decrease in the reaction intensity of the Golgi region, while reactions appeared over other parts of the cells: lysosomes, secretory material, and plasma membrane. The intensity of the reactions observed over the plasma membrane varied considerably in various cell types; furthermore the reactions were restricted to the apical surface in some types, but extended to the whole surface in others. Since the plasma membrane is covered by a "cell coat" composed of the carbohydrate-rich portions of membrane glycoproteins, it is concluded that newly formed glycoproteins, after acquiring fucose in the Golgi apparatus, migrate to the cell surface to contribute to the cell coat. This contribution implies turnover of cell coat glycoproteins, at least in nonrenewing cell types, such as those of kidney tubules. In the young cells of renewing populations, e.g. those of gastro-intestinal epithelia, the new glycoproteins seem to contribute to the growth as well as the turnover of the cell coat. The differences in reactivity among different cell types and cell surfaces imply considerable differences in the turnover rates of the cell coats.

Animals↗