“…While sev eral laboratories have recently reported the growth of endothelial cells in culture [9. 15, 22, 28] their unequivocal identification re mains a problem since enzymes characteristic of these cells are not always expressed in vi tro [10,22,28]. It has been shown by Cossio et al [7,8] using the indirect immunofluorescent technique that sera from patients with Chagas' disease (a South American trypano-somiasis caused by the protozoan Trypano soma cruzi) contain immunoglobulins which bind both to the interstitium and blood ves sels of heart and skeletal muscle, to heart en docardium, and to vascular structures of liver, kidney, stomach and placenta.…”