Radiolabeled hypoxic cell sensitizers: tracers for assessment of ischemia

Hypoxic, non-functional, but viable, tissue may exist in heart and brain following an arterial occlusion. Identification of such tissue in vivo is crucial to the development of effective treatment strategies. It has been suggested that certain compounds capable of sensitizing hypoxic tumor cells to killing by x-rays (i.e., misonidazole) might serve as in vivo markers of hypoxic tissue in ischemic myocardium or brain if properly radiolabeled. To this end we have radiolabeled two fluorinated analogs of nitroimidazole based hypoxic cell sensitizers with the 110 minute half-lived positron-emitting fluorine-18. The ability of these tracers to quantitate the presence of hypoxic tissue has been studied in a gerbil stroke model. The in vivo uptake of one of these tracers [F-18]-fluoronormethyoxymisonidazole is dependent on the extent of tissue hypoxia, and thus, appears to have potential as a diagnostic indicator of non-functional but viable tissue when the tracer is used in conjunction with positron emission tomography.     

PENICILLIN AS AN ETIOLOGIC FACTOR IN ECTOPIC PREGNANCY

Among patients observed in private practice the incidence of ectopic pregnancy trebled after the advent of penicillin therapy in the treatment of chronic pelvic inflammatory disease. In seven of eleven cases of ectopic pregnancy in a two-year period, the patients had had penicillin therapy previously. A probable explanation is that in cases in which the fallopian tube is closed by inflammation, it reopens following penicillin therapy but, because of residual damage, the ovum may not descend to the uterine cavity and is impregnated in the tube.