RT Journal T1 WHere does fibrinogen arise? JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1925 FD August 15 VO 85 IS 7 SP 519 OP 519 DO 10.1001/jama.1925.02670070039017 UL http://dx.doi.org/10.1001/jama.1925.02670070039017 AB There are few protective devices of the organism more beneficent than the reaction by which fibrinogen, the soluble protein of the circulating blood, is transformed into the insoluble fibrin, which forms the basis of blood clots and prevents continued hemorrhage after injury to blood vessels. Now and then the clot-forming mechanism fails for some reason; and not a little consideration has been devoted in the past to the possible factors concerned in extravascular coagulation, that the occurrence of the latter might be assured or promoted whenever the normal course of the process was threatened. Thus, it has become known that calcium is somehow involved in the chemical transformations leading to clot formation; and other agencies, respectively promoting or inhibiting it, may be involved in addition to fibrinogen. The latter is obviously the factor of preeminent importance and consequently one with respect to which our information should be made as complete