Reviews & Analysis

The recent descriptions of T-cell dynamics in HIV disease have refocused efforts to understand the normal homeostatic processes that maintain T-cell populations (pages 674–680).

Mutations in tumour suppressors often lead to tumorigenesis. But other genetic mechanisms affecting suppressor gene expression can be just as effective (pages 686–692).

The discovery of dopamine transporter density difference in alcoholics has implications for mechanisms of vulnerability and relapse (pages 654–657).

Dynamic interactions between multiple factors underlie alcoholism, including recently described neuroregulatory influences (pages 654–657).

Specific antibodies can slow tumour progression, setting the stage for tumour-cell elimination (pages 644–648).

The role of the CD44 cell surface molecule in tumorigenesis has been the focus of intense debate. Now enough pieces are known to begin putting the puzzle together.

The finding that the drug clotrimazole has potent inhibitory effects on cell proliferation offers new challenges for therapy and biological investigation (pages 534–540).

The road to effective vaccines based on DNA sequences may soon be more easily travelled (pages 583–587).

Despite its early promise, rational drug design for anti-HIV agents has fallen short of expectations, probably because the expectations were too high.

The induction of ulcerative colitis in mice with targeted disruptions of a G protein-encoding gene establishes yet another genetic link between G proteins and disease.

The specific targeting of signal transduction components implicated in vascular disease may be accomplished more efficiently with genes than with drugs (pages 541–545).

Nitric oxide induced by γδ T cells (pages 552–557) and derived from dietary nitrate (pages 546–551) may limit microorganism growth.

Pollutant research is moving indoors as scientists uncover new links between indoor exposure and disease. However, measuring the levels of exposure is a difficult task.

What DNA interactive ligands, such as antitumour agents and carcinogens, can do is well known, but exactly how they do it has been a mystery until now.

Viral resistance is a major problem with current AIDS drugs. The feline immunodeficiency virus model may provide a way to test new drugs and strategies before human trials.

The coevolution of viruses and their hosts has given rise in both to elaborate molecular attack and defence mechanisms (pages 437–441).

Dietary caloric restriction is the only intervention conclusively shown to slow ageing, delay the onset of age-related diseases, maintain function and extend both median and maximal life span in mammals.

The existence of a placental clock controlling the term of pregnancy has long been hypothesized. Now scientists may have uncovered what makes it tick (pages 460–463).

Transplanting organs across species lines presents tremendous difficulties, but the obstacles are no longer insurmountable (pages 423–427).