The reason bacterial endocarditis is difficult to cure has been controversial for many years. One explanation could be that antibiotic diffusion inside the vegetations is heterogeneous. This hypothesis was investigated by means of an autoradiographic study of diffusion of labeled antibiotics into large infected cardiac vegetations of nutritionally variant Streptococcus endocarditis in rabbits. Ten days after infection, 653 microCi of [3H]penicillin, 410 microCi of [3H]tobramycin, or 174 microCi of [14C]teicoplanin were injected iv over 30 min. Thirty minutes after the end of infusion (T30), vegetation/blood radioactivity ratios were 2.48 +/- 1.27, 2.49 +/- 0.67, and 3.94 +/- 1.19 for penicillin, tobramycin, and teicoplanin, respectively. Autoradiography clearly showed that distribution of the three drugs was different: Tobramycin was homogeneously distributed; penicillin was more concentrated at the periphery but still reached the center of vegetations; teicoplanin was concentrated only at the periphery. The same distribution pattern was observed with teicoplanin at T120 (i.e., one t1/2 beta later) and also after simultaneous infusion of a therapeutic dose (15 mg/kg) of cold teicoplanin. The diffusion gradient exhibited by some antibiotics could explain the difficulty in sterilizing vegetations despite high local concentrations, and the deleterious effect of the size of the vegetations on the therapeutic response.

Ballantyne syndrome was first described in association with severe hydrops fetalis caused by rhesus isoimmunization, and lately, in association with diverse etiologies of nonimmunological severe fetal hydrops. This report is a case of typical Ballantyne syndrome in association with lethal hydrops fetalis caused by Ebstein's anomaly. It is likely that any severe fetal hydrops with massive placental hydrops may produce Ballantyne syndrome. Hemodilution could be the main biological feature, differentiating Ballantyne syndrome from usual preeclamptic syndromes. Pathophysiological hypotheses are discussed.

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