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Staphylokinase obtains plasminogen activating activity by forming a complex with plas-minogen. Although the enzymatic activity of staphylokinase is enhanced by fibrin, how fibrin enhances enzymatic activity has not been determined yet. The effects of fibrin, or fibrinogen fragments, on the activation of plasminogen by staphylokinase was investigated using CNBr-digested fibrinogen fragments (FCB-2 and FCB-5) and plasmin-degraded cross-linked fibrin fragments ((DD)E complex, DD fragments and E fragments). Kinetic analysis of the activity of staphylokinase revealed that its plasminogen activating activity, which was expressed as kcatlKm, was enhanced by FCB-2 (10-fold) and FCB-5 (5-fold). These fibrin fragments caused 38-, 30-, and 8.5-fold increases in activity for the DD fragment, (DD)E complex and E fragment, respectively. Although a,-antiplasmin inhibited the activation of plasminogen by staphylokinase, FCB-2 abolished its inhibitory effects, and the plasminogen activating activity of staphylokinase was restored. The inhibitory effects of a,-antiplasmin on the activation of mini-plasminogen by staphyloki-nase were less than for Glu-or Lys-plasminogen, and the inhibitory effect of a,-antiplasmin was not altered by fibrin or EACA. These findings indicate that the staphylokinaselplasmin-(ogen) complex reacts with fibrin even in the presence of a,-antiplasmin, and efficient plasminogen activation takes place on the surface of fibrin.

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Background Severe aortic stenosis (AS) is increasing in the aging society and is a serious condition for anesthetic management. However, approximately one-third of patients with severe AS are asymptomatic. Echocardiography is the most reliable method to detect AS, but it takes time and is costly. Methods Data were obtained retrospectively from patients who underwent surgery and preoperative transthoracic echocardiography (TTE). LVH on ECG was determined by voltage criteria (Sv 1 + Rv 5 or 6 ≥3.5 mV) and/or the strain pattern in V 5 and V 6 . Severe AS was defined as a mean transaortic pressure gradient ≥40 mmHg or aortic valve area ≤1.0 cm 2 by TTE. Results Data for 470 patients aged 28–94 years old were obtained. One hundred and twenty-six patients had severe AS. LVH on ECG by voltage criteria alone was detected in 182 patients, LVH by strain pattern alone was detected in 80 patients and LVH by both was detected in 55 patients. Multivariable logistic analysis revealed that LVH by the strain pattern or voltage criteria, diabetes mellitus, and age were significantly associated with severe AS. The AUC for the ROC curve for LVH by voltage criteria alone was 0.675 and the cut-off value was 3.84 mm V, and the AUC for the ROC for age was 0.675 and the cut-off value was 74 years old. Conclusion Our study suggests that patients who are 74 years old or over with LVH on ECG, especially those with DM, should undergo preoperative TTE in order to detect severe AS.