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Xenotransplantation continues to present daunting scientific hurdles but there is now a genuine prospect for clinical application. There are also significant and unknown risks. We call for a moratorium on all human xenotransplantation and offer a strategy for balancing the ethical, medical, scientific and societal demands of xenotransplantation prior to human clinical trials.
Detailed analysis of the dramatic T cell changes accompanying HIV disease point to homeostatic dysregulation as a primary cause of immunodeficiency (pages 208–214 and 215–221).
Studies in knockout mice suggest that the clot busting drug tPA harms neurons; experience in acute ischemic stroke patients says otherwise (pages 228–231).
The finding of leukemic cells in the newborn blood of infants who developed acute leukemia in the first few years of life suggests that some leukemias are present in utero.
Clinical results show that raloxifene benefits heart and bone in postmenopausal women without increasing the risk of uterine cancer but its long-term effects are unknown.
Correlating BOLD functional magnetic resonance imaging with metabolic changes during neuronal activation should benefit the study of cognitive processing (pages 159–167).
Recent results showing decreased receptor binding in the brainstem of children with SIDS are consistent with a primary cardiovascular failure in this syndrome.
