Comparison of unfractionated heparin, low-molecular-weight heparin, low-dose and high-dose rivaroxaban in preventing thrombus formation on mechanical heart valves: results of an in vitro study

2011 ◽  
Vol 32 (4) ◽  
pp. 417-425 ◽  
Author(s):  
Anja Kaeberich ◽  
Iris Reindl ◽  
Uwe Raaz ◽  
Lars Maegdefessel ◽  
Alexander Vogt ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Heart Valves ◽  
Low Dose ◽  
Thrombus Formation ◽  
In Vitro Study ◽  
Mechanical Heart Valves ◽  
Low Molecular Weight ◽  
High Dose

Neutralization of a Low Molecular Weight Heparin (LHN-1) and Conventional Heparin by Protamine Sulfate in Rats

1986 ◽  
Vol 56 (03) ◽  
pp. 318-322 ◽  
Author(s):  
V Diness ◽  
P B Østergaard
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Thrombus Formation ◽  
Experimental Models ◽  
Protamine Sulfate ◽  
Low Molecular Weight ◽  
Antithrombotic Effect ◽  
Higher Doses

SummaryThe neutralization of a low molecular weight heparin (LHN-1) and conventional heparin (CH) by protamine sulfate has been studied in vitro and in vivo. In vitro, the APTT activity of CH was completely neutralized in parallel with the anti-Xa activity. The APTT activity of LHN-1 was almost completely neutralized in a way similar to the APTT activity of CH, whereas the anti-Xa activity of LHN-1 was only partially neutralized.In vivo, CH 3 mg/kg and LHN-1 7.2 mg/kg was given intravenously in rats. The APTT and anti-Xa activities, after neutralization by protamine sulfate in vivo, were similar to the results in vitro. In CH treated rats no haemorrhagic effect in the rat tail bleeding test and no antithrombotic effect in the rat stasis model was found at a protamine sulfate to heparin ratio of about 1, which neutralized APTT and anti-Xa activities. In LHN-1 treated rats the haemorrhagic effect was neutralized when APTT was close to normal whereas higher doses of protamine sulfate were required for neutralization of the antithrombotic effect. This probably reflects the fact that in most experimental models higher doses of heparin are needed to induce bleeding than to prevent thrombus formation. Our results demonstrate that even if complete neutralization of APTT and anti-Xa activities were not seen in LHN-1 treated rats, the in vivo effects of LHN-1 could be neutralized as efficiently as those of conventional heparin. The large fall in blood pressure caused by high doses of protamine sulfate alone was prevented by the prior injection of LHN-1.

INDUCTION OF OSTEOPOROSIS IN RATS BY STANDARD HEPARIN AND LOW MOLECULAR WEIGHT HEPARIN

1987 ◽  
Author(s):  
T Mätzsch ◽  
D Berggvist ◽  
U Hedner ◽  
B Nilsson ◽  
P Østergaard
Keyword(s):  
Molecular Weight ◽  
Bone Mass ◽  
Low Molecular Weight Heparin ◽  
Low Dose ◽  
Term Treatment ◽  
Ash Content ◽  
Low Molecular Weight ◽  
High Dose ◽  
Degree Of Reduction ◽  
Long Term Treatment

Long-term treatment with heparin can induce osteoporosis. This complication is suspected to be related to the dosage of heparin rather than to duration of therapy, but the mechanism by which heparin induces osteoporosis is unknown. In a previous study we reported the same degree of reduction in mineral bone mass in rats after treatment with 2 IU heparm/g bw for 33 and 65 days (Thromb Haemostas 1986,56:293-4). Using the same animal model we compared the effect of a high-dose standard heparin (SH) and a low molecular weight heparin (LMWH) in a high and a low dose on the mineral bone mass in the femur of rats. Method: 60 female Wistar rats (207±1.8 g) were randomly allocated to treatment with either 2 Xal U/g bw of standard heparin (SH), 2 Xal U/g bw of LMWH ("high-dose"), 0.4 Xal U/g bw LMWH ("low-do-se") or placebo (saline). A standard sodium salt heparin of porcine origin was used, and the LMWH was an enzymatically depolymerized pork mucosal heparin (LHN-1, mean MW 4900 D). Treatment with s.c. injections was continued for 34 days. 24 hours after the last injection the rats were sacrificed and the carefully cleaned femora weighed in air and in water under standardized conditions. Volumes and densities were calculated from the weights. The bones were then incinerated for 48 hours at 600°C and weighed again to determine the ash content (expressed as ash weight per ml of unashed femur volume). Results: There was a significant decrease in ash content (p<0.01) and density (p<0.01) of the femora in all heparin treated groups as compared with controls. High-dose LMWH caused the same reduction in bone mineral mass as standard heparin. Treatment with low-dose LMWH resulted in a significantly less pronounced reduction in ash content (p<0.001) and density (p<0.05) of the femora when compared with high-dose standard heparin and high-dose LMWH. CONCLUSION: Daily injections of 2 Xal U/g body weight of standard heparin or low molecular weight heparin for 34 days causes the same degree of reduction of mineral bone mass in rats. The reduction of mineral bone mass in rats by treatment with low molecular weight heparin is dose dependent.

Low molecular weight heparin for the prophylaxis of thromboembolism in women with prosthetic mechanical heart valves during pregnancy

2004 ◽  
Vol 92 (10) ◽  
pp. 747-751 ◽  
Author(s):  
Aviva Lee-Parritz ◽  
ack Ansell ◽  
Betul Oran
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Heart Valves ◽  
Factor Xa ◽  
Thromboembolic Complication ◽  
Mechanical Heart Valves ◽  
Fixed Dose ◽  
Low Molecular Weight ◽  
Promising Alternative ◽  
Prosthetic Valves

SummaryIncreased thromboembolic events occur in women with mechanical prosthetic valves during pregnancy, and selecting an effective and safe anticoagulant is still a challenge. Low molecular weight heparin (LMWH) is a promising alternative, but a recent warning and label change about its use in patients with mechanical prosthetic valves has caused confusion among physicians. The aim of the present study was to review the risks of maternal and fetal complications with mechanical heart valves treated with LMWH during pregnancy. We performed a review of the current medical literature through MEDLINE and EMBASE (1989 to 2004). Additional data sources included abstract proceedings, and reference lists of selected articles. Among 81 pregnancies in 75 women, the proportion of valve thrombosis was 8.64% (7/81; 95% CI, 2.52%–14.76%). The frequency of overall thromboembolic complication (TEC) was 12.35% (10/81; 95% CI, 5.19%–19.51%). Nine of ten patients with TEC received a fixed dose of LMWH and two of these received a fixed low dose of LMWH. Among 51 pregnancies whose anti-factor Xa levels were monitored, only one patient was reported to have a thromboembolic complication. The frequency of live births with LMWH was 87.65% (95%CI, 80.49%94.81%). In pregnant women with mechanical heart valves, LMWH appears to be a suitable option to a vitamin K antagonist. The use of LMWH warrants monitoring and appropriate dose adjustments to maintain a 4–6 hr post-injection anti-factor Xa level at a minimum of 1.0 U/ml to decrease the incidence of TEC.

scholarly journals e0170 The sensitivity of different reagents for laboratory monitoring of low molecular weight heparin: an in vitro study

Heart ◽  
2010 ◽  
Vol 96 (Suppl 3) ◽  
pp. A54-A55
Author(s):  
S. Xu-Bo ◽  
H. Da-Yi ◽  
W. Jian-Qi ◽  
C. Zhe ◽  
Y. Hai-Rong ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
In Vitro Study ◽  
Vitro Study ◽  
Low Molecular Weight ◽  
Laboratory Monitoring

scholarly journals In Vitro Study of Synergic Effect of Cisplatin and Low Molecular Weight Heparin on Oral Squamous Cell Carcinoma

2020 ◽  
Vol 10 ◽  
Author(s):  
Fabio Camacho-Alonso ◽  
T. Gómez-Albentosa ◽  
R. E. Oñate-Sánchez ◽  
M. R. Tudela-Mulero ◽  
M. Sánchez-Siles ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Low Molecular Weight Heparin ◽  
In Vitro Study ◽  
Low Molecular Weight ◽  
Synergic Effect
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