PubMed Health⌕ Search

Biomedical subjects

E Schram

Publications and source records attributed to E Schram.

17 recordsLinked to original sources
PubMed1989

Improved ATP methodology for biomass assays.

ATP methodology needs to be further standardized and improved in order to avoid the pitfalls that have sometimes hampered its application to biomass assays. The following steps have been reconsidered as far as the bacteriological applications is concerned: (a) destruction of free and somatic ATP: replacement of apyrase by mammalian ATPase, more readily accessible to specific inhibition; (b) extraction of bacterial ATP: protection of luciferase by lipids against inhibitory effect of cationic detergents with production of a constant light response. New methods are proposed for the calibration of luminometers and for the matching of sample holders in multichannel instruments. The limit of sensitivity of ATP assays is discussed in the light of currently available reagents and instruments.

Adenosine Triphosphate↗
PubMed1987

Glucose and erythrocyte ATP: distinctive effects of dipyridamole and of ticlopidine.

This experiment suggests the following points: 1. Erythrocytes in control patients and in atherosclerosis patients seem to have a variable grade of affinity for adenosine and for plasma glucose. This variable grade seems to fix the level of the adenosine triphosphate (ATP) reserves and induces the erythrocytes' deformability. 2. The drop in the level of ATP reserves that induces the poor deformability of the erythrocytes in atherosclerosis patients would appear to be caused by two consecutive shortages: first a shortage that seems to be related to a deficiency of erythrocyte adenosine as the ATP shortage disappears with dipyridamole treatment and then a shortage induced by the lack of erythrocyte glucose and suppressed by the addition of ticlopidine to the dipyridamole treatment.

Adenosine↗
PubMed1986

Platelet hyperaggregability, blood prostacyclin and dipyridamole.

This study demonstrates the presence of PGI2 in blood and its influence on platelet retention tests, possibly by the intermediate of a releasing system in the columns, which is followed by a proximate recuperation on the erythrocyte sites after the passage. The presence of prostacyclin on the erythrocyte sites seems to depend upon the red cell deformability in relation to the good condition of their erythrocyte ATP reserve. The load of the erythrocyte sites increases with the daily dose of dipyridamole. The maximum load of the sites appears to be reached with a daily dose of dipyridamole 450 mg. Approximately 10% of the atherosclerosis patients who have been treated by dipyridamole keep their platelet hyperaggregability and their abnormally lowered prostacyclin level.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

Respiratory profiles of grain handlers and sedentary workers.

During 1978, grain handlers employed at three large inland grain terminals were studied along with an equal number of office workers matched for sex, age and smoking history. Respiratory symptoms and spirometric abnormalities were no more frequent in 16 grain handlers who were non-smokers than in their controls. However, 20 grain handlers who were smokers complained significantly more (P less than 0.01) of grade 1 dyspnea and had significantly lower ratios of forced expiratory volume in the first second to forced vital capacity (P less than 0.05) than their controls. Only 3% of the grain handlers were sensitive to grain dust, and 18% were found to be atopic but to have good lung function. A family history of asthma or allergic rhinitis was no more frequent in the grain handlers than in the control subjects. We conclude that the combination of cigarette smoking and exposure to grain dust causes a deterioration in lung function.

Alberta↗
PubMedDate not supplied

Bioluminescent assay of ATPase activity in embryonic material using firefly luciferase.

The continuous bioluminescent assay of ATP has been adapted to the study of Mg2+-dependent ATPases, including the (Na+; K+) pump, in amphibian tissues. A discrete bioluminescent assay procedure for ATPase has also been developed. Components of the firefly luciferase assay reagent modify the observed ATPase activity but this can be circumvented by performing discrete instead of continuous measurements of enzyme activity. In assays with commercial ATPase preparations the continuous bioluminescent assay procedure gave ATPase activities 2.2-fold lower than obtained with the discrete procedure. In Xenopus oocyte or egg homogenates, in contrast, the total ATPase activity measured is stimulated eight times by the luciferase reagent, mainly through an unexplained activation of a Mg2+-independent ATPase. In other tissues, such as Xenopus brain homogenates, both the continuous and discrete monitoring procedures are equally suitable for the determination of ATPase activity.

Animals↗