Differences of Matrix Metalloproteinase 2 Expression between Left and Right Ventricles in Response to Nandrolone Decanoate and/or Swimming Training in Mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Matrix metalloproteinase (MMP)-2 plays an important role in the remodeling of left ventricles (LVs) and right ventricles (RVs). We investigated the differences of MMP-2 expression between LV and RV in response to nandrolone decanoate (ND), swimming training (ST), and combined ND and ST (NS) in mice, based on their structural, functional, and biochemical characteristics.</p><p><b>METHODS</b>Totally 28 male C57B1 mice (6 weeks old; 20-23 g) were divided into four groups, including the control (n = 7), ND (n = 6), ST (n = 8), and NS (n = 7) groups. After respective treatments for 8 weeks, echocardiographic examination was used to assess the cardiac structure and function. Van Gieson stain was used to examine the fibrosis of LV and RV in response to different treatments, and Western blotting analysis was performed to explore different MMP-2 expressions between LV and RV in response to ND and/or ST. Analysis of variance was used for comparing the four groups.</p><p><b>RESULTS</b>At 8 weeks, right ventricular dimension/body weight in the ND group was larger than the other three groups (F = 7.12, P < 0.05) according to the echocardiographic examination. Fibrosis induced by ND administration was increased more in RV (2.59%) than that in LV (2.21%). MMP-2 expression of the ND group in RV was significantly greater than the control and NS groups in RV and the corresponding ND group in LV.</p><p><b>CONCLUSION</b>The experimental data support the hypothesis that ND administration induces greater MMP-2 expression increase in RV compared to LV, leading to consequent RV dilation.</p>

Effects of low molecular weight heparin on clot rate and activated clotting time: an in vitro study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Due to lack of point-of-care testing, the use of low-molecular-weight heparin (LMWH) therapy in some special patients is restricted. This study was designed to explore the effects of LMWH on clot rate (CR) and activated clotting time (ACT), and to search for an appropriate method for bedside monitoring of anticoagulant activity of LMWH.</p><p><b>METHODS</b>Thirty-two healthy volunteers were selected from the staff of Beijing Tongren Hospital. CR and ACT were measured with different reagents (glass beads, diatomite, kaolin and magnetic bar) on blood samples spiked with increasing concentrations of LMWH (dalteparin, 0.2-1.8 IU/ml). Correlations between concentrations of LMWH and values of CR and ACT were analysed based on the data obtained and regression analysis was performed to establish a regression equation.</p><p><b>RESULTS</b>With the increase in doses of dalteparin, CR values reduced gradually. The values of CR of four reagents (glass beads, diatomite, kaolin and magnetic bar) were 20.4-4.5 IU/min, 27.4-6.9 IU/min, 27.5-7.9 IU/min and 7.8-0.1 IU/min respectively and an linear relationship was observed between the CR values and dalteparin concentrations (P < 0.05). The values of ACT were 173-615 seconds, 130-270 seconds, 123-226 seconds, 337-1411 seconds respectively, which showed a linear regression between the ACT values and dalteparin concentrations (P < 0.01). Differences in slope of the regression curves of ACT were observed with all the reagents tested (glass beads 248.2 s/IU, diatomite 74.8 s/IU, kaolin 58.2 s/IU and magnetic bar 1112.2 s/IU, P < 0.01). While the minimum concentration of dalteparin was 0.2 IU/ml, 0.4 IU/ml, 1.4 IU/ml and 0.2 IU/ml separately, the ACT values of the four coagulants (glass beads, diatomite, kaolin and magnetic bar) were beyond the normal limit and showed a noticeable increase respectively (P < 0.01).</p><p><b>CONCLUSIONS</b>This study showed that there was an excellent linear relationship between the CR and ACT values and dalteparin concentrations for all the four reagents (glass beads, diatomite, kaolin and magnetic bar) in vitro. The sensitivity of different coagulation reagents to LMWH different. Choosing a suitable reagent, both CR and ACT were possible to be used as a convenient bedside test for LMWH.</p>

An angiographic trial to evaluate the efficacy and safety of tenecteplase in Chinese patients with acute myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>In this randomized, open-label, multicenter, angiographic trial, we compared the efficacy and safety of tenecteplase (TNK-tPA) with alteplase (rt-PA) in Chinese patients with acute myocardial infarction.</p><p><b>METHOD</b>Patients with acute ST-elevation myocardial infarction and pain to hospital time within 6 hours from October 2002, to March 2004 were randomly assigned a body weight-adjusted bolus of TNK-tPA (0.53 mg/kg over more than 10 s, n = 58) or front loaded rt-PA (< or = 100 mg, n = 52). Coronary angiography was performed at 90 min after initiating study drugs. All patients received aspirin and heparin (target activated partial thromboplastin time: 50-70 s). The primary end point of the trial was the rate of TIMI grade 3 flow at 90 minutes. Other end points included the rate of TIMI grade 2/3 flow at 90 minutes, all cause mortality at 30 days, the moderate/severe hemorrhage without intracranial hemorrhage (ICH) and ICH within 30 days.</p><p><b>RESULTS</b>TIMI grade 3 flow at 90 minutes (68.4% vs. 66.7%, P = 1.00), TIMI grade 2 or 3 at 90 minutes (89.5% vs. 80.4%, P = 0.278), total mortality at 30 days (13.8% vs. 9.6%, P = 0.565), the rate of moderate/severe hemorrhage (8.6% vs. 5.8%, P = 0.72) and incidence of ICH (3.5% vs. 1.9%, P = 1.00) were all similar in TNK-tPA treated patients compared to rt-PA treated patients.</p><p><b>CONCLUSION</b>The efficacy of single-bolus, weight-adjusted TNK-tPA fibrinolytic regimen is equivalent to front-loaded alteplase in terms of the rates of TIMI grade 3 flow, TIMI 2 or 3 flow. Incidences of moderate/severe hemorrhage, ICH and 30-days mortality were similar in TNK-tPA and rt-PA treated patients.</p>

In vitro anticoagulation monitoring of low-molecular-weight heparin / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although low-molecular-weight heparin has replaced unfractionated heparin to become the primary anticoagulation drug for treatment of acute coronary syndrome, there is no convenient bedside monitoring method. We explored the best laboratory monitoring method of low-molecular-weight heparins (enoxaparin, dalteparin, and nadroparin) by use of the Sonoclot coagulation analyzer to monitor the activated clotting time.</p><p><b>METHODS</b>A total of 20 healthy volunteers were selected and 15 ml of fasting venous blood samples were collected and incubated. Four coagulants, kaolin, diatomite, glass bead, and magnetic stick, were used to determine the activated clotting time of the low-molecular-weight heparins at different in vitro anti-Xa factor concentrations. A correlation analysis was made to obtain the regression equation. The activated clotting time of the different low-molecular-weight heparins with the same anti-Xa factor concentration was monitored when the coagulant glass beads were applied.</p><p><b>RESULTS</b>The activated clotting time measured using the glass beads, diatomite, kaolin, and magnetic stick showed a linear correlation with the concentration of nadroparin (r = 0.964, 0.966, 0.970, and 0.947, respectively). The regression equation showed that the linear slopes of different coagulants were significantly different (glass beads 230.03 s/IU, diatomite 89.91 s/IU, kaolin 50.87 s/IU, magnetic stick could not be calculated). When the concentration of the anti-Xa factor was the same for different low-molecular-weight heparins, the measured activated clotting time was different after the application of the glass bead coagulant.</p><p><b>CONCLUSIONS</b>The glass bead coagulant is most feasible for monitoring the in vitro anticoagulation activity of nadroparin. The different effects of different low-molecular-weight heparins on the activated clotting time may be related to the different anti-IIa activities.</p>