Biomedical subjects

Andreas Wagner

Publications and source records attributed to Andreas Wagner.

57 records · Page 4Linked to original sources

PubMed2002

Estimating coarse gene network structure from large-scale gene perturbation data.

Large scale gene perturbation experiments generate information about the number of genes whose activity is directly or indirectly affected by a gene perturbation. From this information, one can numerically estimate coarse structural network features such as the total number of direct regulatory interactions and the number of isolated subnetworks in a transcriptional regulation network. Applied to the results of a large-scale gene knockout experiment in the yeast Saccharomyces cerevisiae, the results suggest that the yeast transcriptional regulatory network is very sparse, containing no more direct regulatory interactions than genes. The network comprises >100 independent subnetworks.

Gene Deletion↗

PubMed2002

Ramipril prior to thrombolysis attenuates the early increase of PAI-1 in patients with acute myocardial infarction.

In a placebo-controlled, double-blinded, randomized study we evaluated the effect of ramipril prior to thrombolysis on the course of PAI-1 plasma levels and on the frequency of postinfarct ischemic events in patients with acute myocardial infarction. Fifty-one out of 99 patients received 2.5 mg ramipril orally prior to thrombolysis and 12 h later. The blood samples for determination of PAI-1 plasma levels were collected on admission and 2, 4, 8, 12 and 24 h after thrombolysis. Postinfarct ischemic events were registered until coronary angiography was performed and defined as recurrent chest pain and/or evidence of ischemic signs on the ECG (ST-depression or ST-segment elevation of 1 mm in one or more inferior or anterior leads). Coronary angiography was performed within 7 days after the onset of myocardial infarction. Patients were classified into two groups: those without reperfusion of the infarct-related artery (TIMI grade 0 or 1) and those with reperfusion of the infarct-related artery (TIMI grade 2.3). On admission, PAI-1 plasma levels were similar in both groups (ramipril: 47.1 [4.8] ng/ml; placebo: 49.1 [4.8] ng/ml). The PAI-1AUC was 77.2 [6.7] ng/ml/h in the ramipril group and 95.4 [6.2] ng/ml/h in the placebo group (p = 0.013). Significant differences between groups were observed at 4, 8 and 12 h after thrombolysis (4 h: 85.5 (11.3) vs. 116 (12.3) ng/ml, p < 0.01; 8 h: 79.1 (11.2) vs. 100.9 (9.3) ng/ml, p < 0.01; 12 hrs: 71.3 (9.5) vs. 87.4 (7.7) ng/ml, p < 0.05). The relative frequency of postinfarct ischemic events was significantly lower in the ramipril group (2.5% versus 7.1%, p = 0.001). Additionally, we observed a significant higher rate of TIMI grade 2 and 3 of the infarct-related artery in patients receiving oral ramipril compared to the placebo group (73% versus 54%; p = 0.035). Our study demonstrates a favorable effect of ramipril on the fibrinolytic system after thrombolysis associated with a lower rate of postinfarct ischemic events within the first days after myocardial infarction. Therefore, the application of ramipril prior to thrombolysis appears to be a reasonable concomitant treatment which may reduce early infarct-related complications.

Adult↗

PubMedDate not supplied

Reepithelialization of experimental scalds effected by topically applied superoxide dismutase: controlled animal studies.

Highly reactive metabolites, such as oxygen free radicals, initiate a cascade of inflammatory processes in thermally damaged skin, leading to enhanced tissue loss and delayed wound healing. The extent of tissue necrosis in the zone of stasis is of prognostic significance in the wound healing process. In this study, the effect of oxygen free radical removal by recombinant human-Cu/Zn-superoxide dismutase, given in three different formulations during the inflammatory postburn phase and wound repair, was examined. Recombinant human superoxide dismutase was either injected directly into the lesions, spread as enzyme-containing gel onto the burned tissue, or encapsulated into liposomes consisting of 1,2 dipalmitoy-sn-glycero-3-phosphocholine, cholesterol and stearylamine, suspended into a hydrophilic gel and administered to burned animals immediately after trauma. Controls were treated with plain gel or kept untreated. Edema formation, size of lesions, deepening of necrosis, and reepithelialization were examined. Results indicate that superoxide dismutase treatment resulted in reduced and faster recruitment of edema formation, smaller wound sizes, and minor tissue necrosis compared to the controls, thus resulting in significantly faster reepithelialization after 3 weeks. These animal studies on the efficacy of liposomal oxygen free radical scavenger showed accelerated wound healing in all parameters tested.

Administration, Topical↗