PMID- 2847459
OWN - NLM
STAT- MEDLINE
DCOM- 19881206
LR  - 20071206
IS  - 0301-1860 (Print)
IS  - 0301-1860 (Linking)
VI  - 543
DP  - 1988
TI  - Low molecular weight heparins: antithrombotic and haemorrhagic effects and 
      standardization.
PG  - 57-64
AB  - Measurement of the in vitro anticoagulant activities of low molecular weight 
      (LMW) heparins against an unfractionated heparin (UFH) standard has given 
      problems of non-parallel assays, wide variability between laboratories and 
      differences between methods. These problems have been largely overcome by 
      establishment of a new LMW heparin standard against which other LMW heparin can 
      be compared. The LMW heparin standard is calibrated with two separate potencies, 
      one for anti-Xa and the other for thrombin inhibition assays. Animal studies have 
      shown a correlation between the anti Xa and antithrombotic activities of several 
      LMW heparins but, below a M.Wt. of approximately 4,000, this correlation breaks 
      down. This may be partly due to the method of measurement of anti-Xa activity and 
      partly due to the inability of very LMW fragments to potentiate thrombin 
      inhibition, which has recently been shown to be an important component of 
      antithrombotic action. However, substances with either anti-Xa activity alone or 
      thrombin inhibitory capacity alone are less effective antithrombotic agents than 
      heparin. Several studies in animals have shown that LMW heparins give less 
      enhancement of bleeding than UFH, but this does not seem to be due to their 
      anticoagulant effects and may be related to their relative effects on platelets.
FAU - Barrowcliffe, T W
AU  - Barrowcliffe TW
AD  - Division of Haematology, National Institute for Biological Standards and Control, 
      U.K.
FAU - Thomas, D P
AU  - Thomas DP
LA  - eng
PT  - Journal Article
PT  - Review
PL  - Sweden
TA  - Acta Chir Scand Suppl
JT  - Acta chirurgica Scandinavica. Supplementum
JID - 0370305
RN  - 0 (Heparin, Low-Molecular-Weight)
RN  - 0 (Serine Proteinase Inhibitors)
RN  - EC 3.4.21.5 (Thrombin)
RN  - EC 3.4.21.6 (Factor Xa)
SB  - IM
MH  - Animals
MH  - Blood Coagulation/drug effects
MH  - Blood Coagulation Tests/methods
MH  - Factor Xa
MH  - Fibrinolysis/*drug effects
MH  - Hemorrhage/*chemically induced
MH  - Heparin, Low-Molecular-Weight/adverse effects/*pharmacology/standards
MH  - Rabbits
MH  - Serine Proteinase Inhibitors
MH  - Sheep
MH  - Thrombin/antagonists & inhibitors
RF  - 44
EDAT- 1988/01/01 00:00
MHDA- 1988/01/01 00:01
CRDT- 1988/01/01 00:00
PHST- 1988/01/01 00:00 [pubmed]
PHST- 1988/01/01 00:01 [medline]
PHST- 1988/01/01 00:00 [entrez]
PST - ppublish
SO  - Acta Chir Scand Suppl. 1988;543:57-64.