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Critical Care Obstetrics part 43

Critical Care Obstetrics part 43 provides expert clinical guidance throughout on how you can maximize the chances of your patient and her baby surviving trauma. In this stimulating text, internationally recognized experts guide you through the most challenging situations you as an obstetrician are likely to face, enabling you to skillfully:Recognize conditions early-on which might prove life threatening, Implement immediate life-saving treatments in emergency situations, Maximize the survival prospects of both the mother and her fetus | Thrombotic Thrombocytopenic Purpura Hemolytic-Uremic Syndrome and HELLP Figure 32.2 Domain structure of ADAMTS-13 the plasma VWF-cleaving metalloprotease . P propeptide MP metalloprotease proteolytic domain TSP thrombospondin-1-like domain eight are present CUB two non-identical domains containing peptide segments similar to complement components C1r C1s a sea urchin protein and a tone morphogenic protein. Indicates the location of mutations in familial TTP patients that affect secretion or function of ADAMTS-13 above enzyme structure . The percentages of polyclonal autoantibodies directed against specific domains of ADAMTS-13 in 25 patients with acquired idiopathic TTP are indicated below the enzyme structure 79 . This VWF processing activity initially described in 1982 9 is now known to be a specific VWF-cleaving metalloprotease in normal plasma that prevents the persistence in the circulation of ULVWF multimers 8 41 42 . The enzyme degrades ULVWF multimers by cleaving 842Tyr-843Met peptide bonds in susceptible A2 domains of VWF monomeric subunits 43-45 . The VWF- cleaving metalloprotease is number 13 in a family of 18 distinct ADAMTS-type enzymes identified to date that share structural similarities 46 47 . ADAMTS-13 is a ciisintegrin and metalloprotease with eight ihrombo spondin-1-like domains. More precisely plasma ADAMTS-13 is composed of an aminoterminal reprolysin-type metalloprotease domain followed by a disintegrin domain a thrombospondin-1-like domain a cysteine-rich domain containing an arginine-glycine-aspartate RGD sequence a spacer domain seven additional thrombospondin-1-like domains and two non-identical CUB-type domains at the carboxyl-terminal end of the molecule Figure 32.2 . CUB domains contain peptide sequences similar to complement subcomponents C1r C1s embryonic sea wrchin protein egf and bone morphogenic protein-1 48 . ADAMTS-13 is a Zn2 - and Ca2 -requiring 190000-Da glycosylated protein that is encoded on chromosome 9q34. It is produced