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Heart ventricular sections of controls and rats injected with Akt-transduced stem cells. Mangi et al. genetically engineered rat mesenchymal stem cells, using ex vivo retroviral transduction, to overexpress the prosurvival factor Akt to the ischemic rat myocardium (page 1195). The authors were able to regenerate lost myocardial volume and normalize systolic and diastolic cardiac function. Sections are at the level of papillary muscle and are stained with Masson trichrome for collagen (blue) and viable muscle (red). Controls underwent coronary ligation and saline-only injection.
Outspoken doctor Kári Stefánsson founded Iceland's deCODE Genetics to use its citizens' genealogy in the hunt for human disease genes. Here he speaks of his passion for medicine and for his homeland—and about courting controversy in both.
Bone marrow–derived stem cells have been used with some success in animal models to repair ischemic damage to the heart. Overexpression of the survival-promoting signal Akt greatly enhances the ability of these cells to heal a heart after myocardial infarction (pages 1195–1201).
Neuropathic pain syndromes such as phantom limb pain have remained enigmatic to patients, physicians and researchers alike. A new study reveals how nerve damage may alter the pain threshold and lead to such syndromes.
Why are humans particularly susceptible to HIV-1, whereas our monkey cousins are impervious to the virus? Part of the answer may lie with the virus' interaction with a cellular system of defense (pages 1138–1143).
An intestinal peptide that regulates glucose metabolism by stimulating insulin secretion from the pancreas is now shown to enhance learning and memory. The peptide can also protect nerve cells in models of neurodegenerative disorders (pages 1173–1179).
Since the eradication of natural smallpox infection, research efforts have waned and the vaccine is now outdated. Two studies revitalize efforts to create a new smallpox vaccine. One study moves vaccine production from animals into tissue culture; the other examines duration of immunity in already vaccinated individuals (pages 1125–1139 and 1131–1137).
Transplantation of bone marrow between allogeneic donors and recipients poses the risk of developing graft-versus-host disease, mediated by T cells from the graft. Exploitation of naturally occurring regulatory T cells in the graft minimizes this risk while still allowing another crucial function of graft T cells—the eradication of host tumor cells. (pages 1144–1150)
Bacterial signaling systems have come into vogue lately as mediators of successful interactions with the host. Now it appears that human hormones present in the gut interact with one such signaling system.