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H Schreyen

Publications and source records attributed to H Schreyen.

4 recordsLinked to original sources
PubMed1984

Complement activation in patients at risk of developing the adult respiratory distress syndrome.

In this prospective study of 50 patients, 36 of whom developed the adult respiratory distress syndrome (ARDS), early and intense complement activation was demonstrated. These patients were at risk of the ARDS because of multiple injuries, major abdominal surgery, acute pancreatitis, severe burns, or disseminated intravascular coagulation. Abnormal C3 consumption (as measured by the C3d/C3 ratio) and elevated plasma C5a-like activity (as measured by a leukocyte aggregation assay) were associated with, respectively, 84 and 86% of cases of ARDS. Both tests were more sensitive indicators of complement consumption than were assays of total hemolytic complement activity (CH50) or total C3. The C3d/C3 ratio showed a close, inverse correlation with CH50 in 47 healthy subjects, and was increased in 12 control patients after minor surgery. The C5a-like activity was found only in patients at risk of ARDS; it was highly associated with clinical conditions that predispose to the ARDS, but it cannot be considered as a real predictor of ARDS occurrence in these patients. Sequential samples from both sides of the pulmonary circulation showed initial pulmonary clearance followed by the release of C5a-like activity. No simultaneous changes in C3 levels were found, suggesting the possible presence of modulating factors. These observations suggest that other factors (e.g., hypoxia and metabolic cascades) may influence the development of ARDS.

Complement Activation↗
PubMed1978

[Integration othe MG 50 into the routine of a hospital transfusion center].

Groupamatic MG 50 equipment looks to be quite well adapted to suit the needs of small or medium size blood transfusion centers, in which the number of blood grouping determinations daily processed is in the range of 100 to 500. In its present configuration (after some modifications have been brought in), the MG 50 offers significant advantages which will be discussed in detail. For a batch of 58 samples tested in one hour on twelve channels a single technician is required instead of 3 to 4; sample supply of equipment is therefore made in a more regular way. In case of run interrupt a single series of 12 determinations is implicated and can be immediately checked. The whole analysis process is limited to twice 11 minutes due to the continuous agitation of discs. The tubing pump priming is automatically performed and the reagent homogeneity is better insured; the presence of dilution tubes is easily controlled. Different programs are easily interchangeable and make the use of equipment smooth. We do think that MG 50 allows a better distribution of work throughout the day and accepts emergency blood grouping requests without any special difficulty.

Autoanalysis↗
PubMedDate not supplied

Intermediate and long-acting insulin preparations without protamine sulphate are complement activators in vitro.

Recently, we have documented an abnormal in vivo complement metabolism in Type 1 diabetic children treated with monocomponent porcine insulin Monotard MC and its correction after switch-over to human insulin Protaphane HM. This prompted us to investigate the ability of different kinds of insulin preparations to induce complement activation in vitro. Freshly collected serum samples from healthy blood donors were incubated with commercial rapid and intermediate or long-acting (by protamine sulphate (PS) or zinc) insulin preparations for 2 hours at 37 degrees C. The C3d content of the supernatants was measured by turbidimetry as a marker of C3 complement fraction consumption. Only long-acting preparations of insulins without protamine sulphate were associated with highly significant increased levels of C3d, whatever the source of insulin, animal or human. Moreover, addition of exogenous protamine sulphate was able to inhibit the C3 conversion. This effect was dose-dependent and peaked at the concentration of commercial NPH insulin preparations. The mechanism by which protamine sulphate inhibits complement activation in vitro could be related to its ability to interfere with the physical nature of the solid surfaces presented by the insulin crystals. Indeed, insulin crystals were rapidly cleared (< 5 min) in the incubated serum when small doses of protamine sulphate were added. The complement activating capacity of long-acting insulin without protamine was dose dependent, equivalent to the known complement activator Zymosan, and abolished in the presence of EDTA. In conclusion, the present study has documented the ability of some protracted insulin preparations to activate the complement system in vitro if they are devoided of protamine sulphate. On the other hand, short-acting and NPH insulins are not complement activators.

Animals↗