Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Factor VIII, a protein cofactor involved in blood coagulation, functions in vitro on a phospholipid membrane surface to greatly increase the rate of factor X activation by factor IXa. Using gel filtration, rapid sedimentation, and resonance energy transfer we have studied the interaction of recombinant-derived human factor VIII with small and large unilamellar phospholipid vesicles composed of phosphatidylserine and phosphatidylcholine. Resonance energy transfer, from intrinsic fluorophores in factor VIII to dansyl-phosphatidylethanolamine incorporated into vesicles, has been adapted for quantitative equilibrium measurements. Factor VIII binds rapidly and reversibly to small and large vesicles. At 8 degrees C the interaction of factor VIII with small vesicles fits a simple bimolecular model with a KD of 2 nM and a phospholipid binding site defined by 180 phospholipid monomers. At 25 degrees C the binding of factor VIII to small vesicles containing 20% phosphatidylserine can be described by an apparent KD of 4 nM; the phospholipid/protein ratio at saturation was 170. Binding to large vesicles was demonstrated with a KD of 2 nM and a phospholipid/protein ratio at saturation of 385. Binding was dependent upon the phosphatidylserine mole fraction and was nonlinear from 0 to 30% phosphatidylserine content. A direct comparison of factor VIII and factor V binding indicated that the affinity of factor V to phospholipid vesicles was equivalent to that of factor VIII and that the phosphatidylserine requirement was lower. A model is proposed to explain the nonlinear phosphatidylserine dependence of binding for factor VIII.
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PMID:Binding of human factor VIII to phospholipid vesicles. 210 32

Four monoclonal anti-VIII:C antibodies were obtained from the fusion of the splenocytes of one Balb/C mouse with a specific activity ranging from 2.3 to 45,000 U/mg when purified from ascitic fluid. Only one antibody was able to inhibit completely Factor VIII:C in normal plasma. The four antibodies could bind Factor VIII:CAg in plasma and commercial concentrate both in liquid and solid phase, and were suitable for immunopurification of Factor VIII:C. Three antibodies competed with polyclonal anti-VIII:CAg Fab' in a liquid phase IRMA, and all of them were able to displace their own binding to Factor VIII:CAg. Competition studies between monoclonal antibodies for the binding to Factor VIII:CAg were performed and showed the recognition of different epitopes and various functional impact. These studies indicate that at least one antibody, with the lowest anti-VIII:C titer clearly recognizes a different epitope of VIII:C than those recognized by the others. Affinity constants ranged from 10(9) to 10(10) l/mole.
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PMID:Characterization of four monoclonal antibodies to factor VIII coagulant protein and their use in immunopurification of factor VIII. 243 29

Forty-nine Spitz nevi occurring in children were reviewed and sampled extensively in order to assess the incidence of vascular invasion. Evidence of vascular invasion was found in seven (14.3%) cases. The endothelium of such vessels was negative on immunoperoxidase staining for Factor VIII-related antigen suggesting the nevus cells to be in lymphatic channels and not blood vessels. No unusual histological or clinical features characterized the group. All patients are alive and well some years after local excision therapy. It is concluded that lymphatic invasion by nevus cells in Spitz nevi is not uncommon and its presence should not tempt the pathologist into a diagnosis of melanoma.
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PMID:Lymphatic invasion in Spitz nevi. 391 99