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Biomedical subjects

D Guy

Publications and source records attributed to D Guy.

16 recordsLinked to original sources
PubMed1995

Successful repair of a ruptured postinfarct pseudoaneurysm of the left ventricle.

We report a case of a 60-year-old woman who underwent emergency surgical repair of a ruptured pseudoaneurysm of the left ventricle 10 days after acute myocardial infarction. The repair consisted of oversewing the rupture (2 cm long) on the posterior wall under cardiopulmonary bypass. The patient made a satisfactory recovery.

Aneurysm, False↗
PubMed1989

Rate of weight loss during underfeeding: relation to level of physical activity.

The kinetics and bioenergetic-metabolic determinants of weight loss were examined in obese women ingesting 900 kcal/d for 5 weeks. The patients were assigned either to a sedentary group (n = 5) or to an exercise group (n = 6) in which the participants expended an additional (X +/- SD) 346 +/- 61 kcal/d in aerobic physical activity. The percentage weight loss and the fractional rates (K1 = fast component; K2 = slow component) of weight loss were almost identical between the two groups. The failure of added exercise to increase the velocity of weight loss could not be explained by differences between the groups in any of the following: gastrointestinal energy and nitrogen (N) absorption; fractional rates of urinary urea N and total N loss; or the thermic effect of the formula diet. The cumulative and fractional rates of protein (ie N) loss were also similar between the groups. The exercise group lost more fat (5.3 +/- 1.0 kg) than the non-exercise group (4.4 +/- 1.6 kg, P less than .001) as measured by underwater weighing. The maximum between-group difference in the rate of fat loss, as determined by energy-N balance, occurred during early underfeeding. With continuation of the 900 kcal/d diet, the between-group differences in the rate of fat loss diminished. The exercise subjects significantly lowered their resting heat losses relative to the non-exercise subjects (P less than .025). This in turn reduced the degree of negative energy balance in the more energy-deficient exercise group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Expenditures for nonspecific back injuries in the workplace.

This study reports results based on the 29,421 Tennessee Workers' Compensation claims that were closed in 1986. The study encompasses over $160 million in paid claims. Nearly 8000 cases (27%) involved back injuries, of which more than 90% were nonspecific. Forty percent of the total expenditures were for these nonspecific back injuries. Counterpart data on 8696 injuries involving extremities are included for comparison. Medical expenses account for about 40% of all payments. Data concerning time intervals between injury and return to work are provided. Separate analyses reveal characteristics of those subjects in the highest total expenditure decile, the 2941 subjects who received 57% of total dollar payments. This report provides fiscal data supporting recent appeals for a reappraisal of the clinical management of nonspecific back problems.

Back Injuries↗
PubMed1988

Chemotactic activity of endothelial cell-derived interleukin 1 for human tumor cells.

Endothelium and the vascular basement membrane form important barriers between the circulation and extravascular compartment. Cancer cell motility contributes to the passage of metastatic cells across this barrier, an essential step in tumor dissemination. In this study we found that the conditioned media of human endothelial monolayers contained a chemoattractant for neoplastic cells and that the chemoattractant activity was greater in the media of cultures which had been stimulated 4 h previously with 10 micrograms/ml bacterial lipopolysaccharide or the peptide formyl-L-methionyl-L-leucyl-L-phenylalanine at a concentration of 10(-6) M. The generation of this activity correlated with the expression of intracellular mRNA for interleukin 1 (IL-1) and with the presence of IL-1 biological activity in the conditioned media. The chemotactic activity in these media was lost after they had been incubated with anti-IL-1. Finally, recombinant human IL-1 alpha and IL-1 beta stimulated dose-dependent, random, and directed migration of human tumor cell populations in the Boyden chamber assay. Thus, this paper describes a mechanism by which the production of IL-1 by endothelial cells could modulate the behavior of tumor cells within the circulation.

Cell Movement↗
PubMed1980

Surface properties of cells isolated from non-metastasizing and metastasizing hamster lymphosarcomas.

Present evidence suggests that the cell surface has an important role in metastasis. To examine this idea further, the surface properties of single cells isolated from the primary growths of a liver-metastasizing (ML) and a non-metastasizing (NML) lymphosarcoma were compared for adhesion to cell monolayers, cytopherometry, isoelectric focusing, adhesion to immobilized lectins and surface labelling with lactoperoxidase-catalysed radioiodination. It was found that the ML cells had increased adhesion to 3 out of 4 of the monolayers studies; a lower overall surface charge but greater peripheral concentrations of charge; and increased surface expression of the fucose moiety. No consistent difference between the two cell types was detected in the electrophoretic pattern of the labelled surface proteins. These findings are discussed in the light of present knowledge of the cell surface, and it is concluded that the significance of any of the observed changes in relation to metastasis has yet to be established.

Animals↗
PubMed1979

Surface protein distributions in cells isolated from solid tumours and their metastases.

Methods have been developed which isolate single viable cells from the primary growths of two tumour systems (a lymphosarcoma and a carcinoma) and their secondary deposits. Subsequent comparisons of the surface-membrane structure of pairs of these primary and secondary cells, using lactoperoxidase-catalysed radioiodination coupled with polyacrylamide-gel electrophoresis, suggest that their overall structures are qualitatively very similar. This latter picture is still maintained when the isolated cells are treated with trypsin or incubated in complete medium before radioiodination. Analysis of the incorporated label into defined sections of the electrophoretic patterns revealed small quantitative differences between primary and secondary cells. In particular, slightly reduced incorporation into certain surface components of secondary cell preparations was seen. However, these did not occur for all the animals investigated, and also they did not consistently occur if the isolated cells were incubated in complete medium. The most similar overall change observed for the two tumour systems was a slight reduction in the secondary cells of a 20K mol. wt surface component.

Animals↗
PubMed1979

A simple lectin-mediated cell-adhesion method for investigating the cell surface.

A very simple, rapid and reproducible method has been developed for studying the interaction of lectins with the cell surface. This involves determining the number of adherent cells after shaking cell suspensions in Petri dishes which have had a lectin coupled to their surface using 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfonate. Using concanavalin A coupled to 60 mm diameter dishes and between 1.5 and 2 x 10(6) tumour cells, this adhesion reached a maximum after 10 min shaking. Maximum cell adhesion also varied according to the particular lectin used. Adhesion was absent or was very low if cells were shaken in untreated dishes, or in dishes coupled to bovine serum albumin, or in the presence of the lectin-specific sugar-competitor. Under conditions of maximum cell adhesion, the binding of two different lymphosarcoma lines to four different lectins was very similar, whereas the binding of a carcinoma line to these lectins was completely different from that observed for the lymphosarcomas.

Animals↗
PubMed1977

Radioiodination studies of tumour cell-surface proteins after different disaggregation procedures.

The surface of single cells isolated from solid tumours by either a mechanical or an enzymatic method have been compared, using lactoperoxidase-catalyzed radioiodination of the tyrosine-containing proteins. Qualitatively, the patterns of surface labelling were similar, and duplicate experiments indicated that each method of isolation gave reproducible results. Analysis of incorporated label into 4 defined sections of the electrophoretic pattern illustrated quantitative differences. When the cells were isolated mechanically, the incorporation into low-mol.- wt. components was considerably reduced, whereas that into the high-mol.-wt. components was unaffected. Treatment of enzymatically isolated cells with trypsin also reduced incorporation into low-mol.-wt components.

Animals↗
PubMedDate not supplied

Nitrogen utilization from elemental diets.

Repletion experiments were performed in malnourished, chair-adapted primates to explore recently reported differences in nitrogen utilization from elemental diets. Two elemental diets were fed consecutively for 8 days through a gastrostomy. Diet C (maltodextrins, peptides, crystalline amino acids) resulted in: larger weight gain (F1,6 = 17.93, p less than 0.01); smaller decrease of serum albumin (F1,5 = 11.2, p less than 0.015), larger increase in total iron binding capacity (F1,6 = 30.6, p less than 0.002), and a more positive nitrogen balance (F1,6 = 30.4, p less than 0.002) than diet V (glucose oligosaccharides, crystalline amino acids). Diet C was considered to be more effective in the nutritional repletion of the study animals. Additional experiments were performed in normal human volunteers to investigate the metabolic fate of ingested glutamine and whether the rapid catabolism and excretion of the amido nitrogen of this amino acid, which constitutes 11.56% of total nitrogen in diet V, could explain the differences observed in primates in our study and in human subjects by other authors. Six normal volunteers were fed 15N amino glutamine, 15N alanine, or 15N H4Cl. Similar amounts of 15N from Gln and Ala were excreted in 10 hr. The amido group of glutamine does not seem to be metabolized differently from the alpha-amino group of alanine under the conditions of the study. The marked differences in nitrogen utilization from the study diets could not be explained by the presence of relatively large amounts of glutamine in one of them.

Adult↗