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This study reports an unusual subpopulation of rats bearing transplanted tumors approximately 50% of the total and apparently unrelated to the presence of metastases, that exhibited shortened bleeding times despite reduced platelet numbers and/or fibrinogen levels. The remaining rats exhibited the expected inverse relationships between bleeding time and platelet numbers and/or fibrinogen level. Tumors were hepatomas and squamous cell carcinomas initially induced in the Fischer strain of rats and carried by passage through tissue culture or syngenic recipient animals.

Collagen induces a saturable 125I-fibrinogen binding to normal human platelets. A role for secreted ADP in this process is supported by studies on 2 patients with the Chédiak-Higashi syndrome. Both collagen-induced nucleotide release and 125I-fibrinogen binding were strongly reduced while ADP-induced fibrinogen binding was normal. Platelets from 2 patients with the gray platelet syndrome bound normal amounts of 125I-fibrinogen in the presence of ADP or collagen despite the severe reduction of secretable alpha-granule proteins. Binding did not occur to collagen-stimulated type I thrombasthenic platelets which lacked GPIIb-IIIa complexes but was detected in amounts which correlated with the residual concentrations of GPIIb-IIIa in the platelets of a patient with type II disease. Our results allow us to propose that collagen-induced fibrinogen binding to normal platelets requires the presence of GPIIb-IIIa complexes and secreted ADP but proceeds independently of alpha-granule release.

Dilatation and evacuation was reported recently to be a safe and effective method for the treatment of intrauterine fetal death. The current authors have treated ten cases of intrauterine fetal death with dilatation and evacuation. Five patients (50%) developed coagulopathy, one of whom also developed endometritis. Patients who developed coagulopathy were significantly older than those who did not. Previous pregnancy also was associated with the development of coagulopathy. Five of six multigravidas developed coagulopathy, whereas none of the four primigravidas developed this complication. Other factors that may have contributed to the development of coagulopathy are discussed. The authors conclude that dilatation and evacuation for midtrimester intrauterine fetal death may not be as safe as has been reported.