News & Views in 2001

Behavioral studies demonstrate that the central mechanism involved in cocaine relapse is closely linked to the sites where marijuana has its effect, suggesting that cannabinoid receptor antagonists may be used as anti-craving agents. (pages 1151–1154)

Several knockout mouse models of leanness and obesity resistance have been reported over the past several years and have advanced our understanding of the pathogenesis and treatment of obesity. A new lean mouse model has been generated by inactivating the gene for an inhibitor of mRNA translation. (pages 1128–1131)

One neuronal characteristic of Parkinson disease is the presence of Lewy bodies–intracytoplasmic accumulations of protein. A new study draws a molecular link between the formation of these bodies, the ubiquitin protein degradation system, parkin and synphilin-1. (pages 1144–1150)

Reflex epilepsies are caused by different sensory stimuli. The report of a gene that, when mutated, causes epileptic seizures in response to loud noises may provide important clues into the mechanisms of neuronal excitability.

It has been known for over 20 years that vascular leakage in inflammation is dependent on neutrophils. The identification of the permeability-enhancing activity produced by neutrophils provides clues to the development of anti-inflammatory drugs with a new mechanism of action (pages 1123–1127).

The respiratory control system responds to hypoxia by increasing the rate of breathing. The finding that nitric-oxide–related molecules might control the ventilatory response to hypoxia suggests possible moleculartargets for the treatment of apnea.

One of the few consistent features of preeclampsia is an increased vascular responsiveness to the pressor agent angiotensin II. New data indicates that a novel heterodimer of the G-protein–coupled angiotensin II type I and bradykinin B₂ receptors might be involved in the molecular mechanism of this phenomenon. (pages 1003–1009)

A new study shows that endothelial progenitor cells obtained from peripheral blood provide a suitable cell source for lining vascular grafts. This finding promises both short- and long-term medical advances in the cardiovascular and other medical arenas. (pages 1035–1040)

Although it acts as a principal neurotransmitter in the brain, glutamate can be highly destructive if released in excess. Glutamate neurotoxicity has been implicated in stroke, head trauma, multiple sclerosis and neurodegenerative diseases. New research suggests that this abundant amino acid might also be involved the growth of brain tumors. (pages 1010–1015)

One of the mysteries about stem cells in the adult brain is where they arise during development. A recent study of human neural stem cells transplanted into monkey embryos provides insight into the derivation of these cells in the primate embryo.

The clinical impact of HIV in developed countries has been markedly reduced through the use of combination antiretroviral drug therapy. But strains of HIV resistant to some or all of these drugs have evolved and are spreading. How fast will they grow? (pages 1016–1020)

A new study shows that a mouse model of cystic fibrosis has lower levels of liquid on the surface of its airway epithelium which suggests that thickened airway secretions might have a role in the disease process and that rehydrating the airways might be of benefit to patients.

Although the tuberculosis bacterium is most renowned for its ability to cause pulmonary infection, the bacilli colonize many sites in the body in addition to the lungs. The recent identification of a key player in the dissemination of infection sheds light on the route by which tuberculosis spreads from the lungs and opens the way to assessing the significance of dissemination to the course of disease.

Obesity and insulin resistance enjoy a complex relationship that gives rise to a range of metabolic disorders, including type 2 diabetes, dyslipidemia and coagulation disorders. Teasing apart this relationship could yield new therapies to treat some of these conditions and two new reports point to the adipocyte-secreted protein, adiponectin, as a new molecular target. (pages 941–946 and pages 947–953)

Patients with hepatitis C constitute the highest proportion of candidates for liver transplantation. The lack of small animal models for the disease has been a major stumbling block in understanding how hepatitis C and liver damage develop and in testing possible treatments. The report of infection of a mouse model with the hepatitis C virus is a significant and welcome achievement. (pages 927–933)