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Biomedical subjects

D Hey

Publications and source records attributed to D Hey.

At least 19 recordsLinked to original sources
PubMed2006

Proton radiography of a laser-driven implosion.

Protons accelerated by a picosecond laser pulse have been used to radiograph a 500 microm diameter capsule, imploded with 300 J of laser light in 6 symmetrically incident beams of wavelength 1.054 microm and pulse length 1 ns. Point projection proton backlighting was used to characterize the density gradients at discrete times through the implosion. Asymmetries were diagnosed both during the early and stagnation stages of the implosion. Comparison with analytic scattering theory and simple Monte Carlo simulations were consistent with a 3+/-1 g/cm3 core with diameter 85+/-10 microm. Scaling simulations show that protons>50 MeV are required to diagnose asymmetry in ignition scale conditions.

Journal Article↗
PubMed1978

[Clinical and in-vitro studies of the therapeutical range of acetylsalicylic-acid to prevent deep vein thrombosis (author's transl)].

In three consecutive studies, acetylsalicyliclysine using the dosages 0.9 g/48 h, 1.8 g/24 h and 3.6 g/24 h, was examined in order to see its effect in preventing deep vein thrombosis (DVT) after elective hip joint surgery. DVT was diagnosed by the 125-i-fibrinogen-test. No reduction of postoperative DVT was found under any of the administered AS-lysine dosages. The collagen-induced platelet aggregation was significantly decreased in all three groups. However, under the low AS-lysine dosages, aggregation was less inhibited with the incidence of DVT than without DVT. In the group with the 3.6 g-dosage, aggregation was maximally inhibited, without any significant difference related to the occurrence of DVT. The results reveal no therapeutic range of AS-lysine to prevent postoperative venous thrombosis.

Aged↗
PubMed1977

[Informative value of control methods for postoperative supervision of medication with aspirin and heparin (author's transl)].

Under the effect of acetylsalicyl lysin, a postoperative hypercoagulability was ascertained with regard to shortened antithrombin and partial prothrombin times. The inhibition of aggregation was easily demonstrable with a high concentration of collagen in the test batch and showed a striking relationship to the occurrence of thrombosis. Under heparin prophylaxis, normal coagulability was maintained. Since disorders of hemostasis due to therapy occur sporadically, early postoperative raising of the dose of heparin should only be done under regular laboratory controll, to which activated PTT and antithrombin time is well suited.

Aged↗
PubMed1977

The activation of intravascular coagulation by bromocarbamide.

In the rabbit the application of a non-lethal, sleep-inducing dose of bromisovalerianyl carbamide (0.5 g/kg body weight) causes an activation of the coagulation system. This activation is manifested by shortened thrombin and partial thromboplastin times and a decrease of fibrinogen concentration and Factor V activity. In contrast, pentobarbital sodium at a dose (62.5 mg/kg) which causes the same changes in arterial partial oxygen pressure and arterial pH does not influence the coagulation system. The bromocarbamide-induced changes in the coagulation system are not to be considered as a result of hypoxia and acidosis but seem to be caused by early endothelial and tissue lesions which result in the release of procoagulatory substances. In healthy test persons a single dose of 1.5 g bromisovalerianyl carbamide has no demonstrable influence on the system of hemostasis.

Adult↗
PubMed1976

Combined administration of low dose heparin and aspirin as prophylaxis of deep vein thrombosis after hip joint surgery.

The study was carried out on 75 patients undergoing hip joint surgery. The efficacy of a prophylaxis of deep vein thrombosis (DVT) by acetylsalicyclic lysine (ASL) and by a low dose heparin (LDH) combined with the ASL treatment was investigated using the 125I-fibrinogen test. DVT was not significantly decreased by the ASL application (53%) compared to the controls (60%). DVT occurred significantly less under the combined administration (27%) than in the other two groups.

Adult↗
PubMed1975

[Effectiveness of subcutaneous heparin in the prevention of thrombo-embolism after major hip operations (author's transl)].

Low doses of heparin were administered subcutaneously to 103 patients starting the evening before major hip operations, while a further 95 were given calcium heparinate, starting the night after operation in conventional high doses. No anticoagulants were given to 27 patients who served as controls. In none of the patients given anticoagulants was there an increased incidence of postoperative wound complications. But the rate of thrombo-embolism was significantly reduced among those on conventional high doses of heparin. The rate of thromboembolism was also reduced among those on the lower dosage (compared with the control subjects), but this form of prophylaxis was not as effective for patients especially at risk.

Adult↗
PubMed1975

[Effectiveness of thromboembolic prophylaxis in major hip surgery with low doses of heparin using the radiofibrinogen test (author's transl)].

The radiofibrinogentest was applied for early diagnosis of deep vein thrombosis (DVT) in 40 patients with major hip joint operations. A high dosage of Calciumdepotheparin (3 X 1 200 IU/10 kg) administered from the evening of the first postoperative day, proved to be a better prophylaxis of DVT in this kind of operation than a low dosage of heparin that administration was started preoperatively.

Female↗
PubMed1974

Platelet function tests in uraemia and under acetylsalicylic acid administration.

Procollagen-induced platelet aggregation, platelet retention (Hellem II), and platelet factor 3 availability (PF-3) were determinded in a group of healthy volunteers,acetylsalicylic acid (ASA) treated patients and in uraemic patients. ASA ingestion did not influence platelet retention and PF-3 availability. Uraemic patients had apronounced decrease in platelet aggregation and retention and PF-3 availability revealed inconsistent alterations. The relevance of the tests and the benefit of an ASA treatment for prophylaxis of thrombosis in Climino fistulae are discussed.

Aspirin↗