Haruyuki Yuasa

Effectiveness of simplified chest compression-only CPR training program with or without preparatory self-learning video: a randomized controlled trial.

OBJECTIVES To evaluate the effectiveness of 1-h practical chest compression-only cardiopulmonary resuscitation (CPR) training with or without a preparatory self-learning video. METHODS Participants were randomly assigned to either a control group or a video group who received a self-learning video before attending the 1-h chest compression-only CPR training program. The primary outcome measure was the total number of chest compressions during a 2-min test period. RESULTS 214 participants were enrolled, 183 of whom completed this study. In a simulation test just before practical training began, 88 (92.6%) of the video group attempted chest compressions, while only 58 (64.4%) of the control group (p<0.001) did so. The total number of chest compressions was significantly greater in the video group than in the control group (100.5+/-61.5 versus 74.4+/-55.5, p=0.012). The proportion of those who attempted to use an automated external defibrillator (AED) was significantly greater in the video group (74.7% versus 28.7%, p<0.001). After the 1-h practical training, the number of total chest compressions markedly increased regardless of the type of CPR training program and inter-group differences had almost disappeared (161.0+/-31.8 in the video group and 159.0+/-35.7 in the control group, p=0.628). CONCLUSIONS 1-h chest compression-only CPR training makes it possible for the general public to perform satisfactory chest compressions. Although a self-learning video encouraged people to perform CPR, their performance levels were not sufficient, confirming that practical training as well is essential. (UMIN000001046).

Effects of fibrin and α2‐antiplasmin on plasminogen activation by staphylokinase

Staphylokinase obtains plasminogen activating activity by forming a complex with plasminogen. 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 kcat/Km, 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 α2‐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 a2‐antiplasmin on the activation of mini‐plasminogen by staphylokinase were less than for Glu‐or Lys‐plasminogen, and the inhibitory effect of α2‐antiplasmin was not altered by fibrin or EACA. These findings indicate that the staphylokinase/plasmin‐(ogen) complex reacts with fibrin even in the presence of α2‐antiplasmin, and efficient plasminogen activation takes place on the surface of fibrin.

Kinetic analysis of plasminogen activation by staphylokinase/plasminogen complex in the presence of fibrin

Staphylokinase (SAK) expresses plasminogen activator activity by forming a complex with plasminogen. In order to elucidate the mechanism for the expression of enzymatic activity of the complex, a cross-linked staphylokinase/plasminogen (SAK/plg) complex was produced with disuccinimidyl suberate, and its enzymatic characteristics were compared with those of a streptokinase/plasminogen (SK/plg) complex. SAK/plg complex and SK/plg complex showed a band with a molecular weight of 110 kDa and 140 kDa by SDS-PAGE under non-reduced condition, respectively. Both complexes exhibited plasminogen activator activity in a concentration-dependent manner on fibrin film and synthetic chromogenic substrate assay. The kinetic analysis of enzymatic activity of both complexes was performed. The plasminogen activator activity of SAK/plg complex was enhanced about 5-fold in the presence of FCB-2. However, SK/plg complex showed only 1.7-fold increase in the presence of FCB-2. These findings indicate that the SAK/plg complex reacts with fibrin, and efficient plasminogen activation is induced on fibrin surface.

Fibrinolytic activity in liver tissues of stroke-prone spontaneously hypertensive rats.

1. Plasminogen activator activity was detected in the extract solution of the liver tissues of both stroke‐prone spontaneously hypertensive rats (SHRSP) and Wistar‐Kyoto (WKY) rats by the synthetic substrate assay.

Evaluation of Airway Scope at Improving the Success Rate of the First Intubation Attempt by Nonexpert Physicians: A Randomized Crossover Manikin Study

Purpose. The aim of the study was to assess the performance of Airway Scope (AWS) on the first attempt at intubation in manikins by nonexpert physicians. Methods. A randomized crossover trial involving seven scenarios. Participants: residents of a cardiovascular hospital. In group A, the AWS procedure was performed first followed by Machintouch Laryngoscopy (ML), while in group B the ML procedure was performed first and then the AWS. The primary outcome assessed was the success of first intubation attempt in a normal scenario. The secondary outcome assessments were success in six other scenarios, and also elapsed time and dental trauma caused in all scenarios. Results. There were 34 participants. All AWS-assisted intubations were successfully completed, but one ML-assisted intubation failed in the normal scenario (). The outcomes achieved by the AWS in scenarios involving cervical immobilization (), tongue edema (), pharyngeal obstruction (), and jaw trismus () were superior to those obtained with the ML. Conclusions. Use of AWS-assisted intubation in manikin scenarios results in a significantly high intubation success rate on the first attempt by nonexpert physicians. These findings suggest this new device will be useful for nonexpert physicians in emergency situations.

Effect of sodium ozagrel on platelet rich plasma clot lysis

Abstract Sodium ozagrel inhibits platelet aggregation through thromboxane (TX) synthetase inhibition. In vitro, the combination of antiplatelet agents with plasminogen activators (PAs) is more effective for thrombolytic therapy than are PAs alone. Therefore, the influence of sodium ozagrel on platelet rich plasma (PRP) clot lysis was investigated in this study. Firstly, PRP clot lysis was performed: PRP clots containing sodium ozagrel were lyzed by a urokinase-type PA. PRP clot lysis was significantly enhanced by sodium ozagrel in a dose-dependent manner. Secondly, clot solubility was investigated by a urea solubility test. The solubility of PRP clots was enhanced by sodium ozagrel in a dose-dependent manner. Moreover, the influence of sodium ozagrel on the density of PRP clots was studied. The density of the PRP clots was decreased by sodium ozagrel in a dose-dependent manner. PAI-1 antigen which was released from activated platelets was reduced by sodium ozagrel in a dose-dependent manner. These findings indicate that the enhancement of PRP clot lysis by sodium ozagrel is due to enhanced solubility, decreased density and reduced PAI-1 antigen release.