HIV infection induces the loss of immunological control of HIV replication but the mechanism involved in altering HIV-specific CD4+ T-cell responses remains unresolved. In May 2 Nature, Daniel Douek and colleagues from National Institutes of Health, Maryland, USA show that the virus replicates unchecked because HIV preferentially infects HIV-specific CD4+ T cells (Nature 2002, 417:95-98).Douek et al. observed that HIV-specific memory CD4+ T cells in infected individuals contain more HIV viral DN

Ascorbic-acid transporter Slc23a1 and vitamin C are essential for maintaining brain integrity and perinatal survival.

Chemical signals play a crucial role in the communication between sperm and egg that facilitates fertilization, but the identity of the signaling molecules involved remains unclear. In May 15 Journal of Experimental Biology, Jeffrey Riffell and colleagues from University of California, Los Angeles, show that the amino acid L-tryptophan is necessary and sufficient to promote recruitment of sperm to the surface of eggs in red abalone (Haliotis rufescens).Riffell et al. investigated the behavioral

Resident T cell receptor-bearing dendritic epidermal T cells have a role in speeding up wound repair.

Cord blood cells are easily available and preserved, and they could potentially serve as a routine starting material for isolation and expansion of cells for allogenic as well as authologous transplantations. But their potential to form human neural cells was unknown. In 15 May Journal of Cell Science, L. Buzanska and colleagues from Polish Academy of Sciences, Warsaw, show for the first time that cells derived from human cord blood can achieve neuronal and glial features in vitro (J Cell Sci 20

in the midgut of its principal vector, the rat flea

Melanocyte stem cells exist in the lower permanent portion of hair follicles and are highly influenced by their niche.

There is no correlation between the risk of acoustic neuroma and mobile phone use.

RBP-J signaling is involved in cell fate determination of marginal zone B cells in the spleen.

For more than 50 years antifolate drug therapy has been used successfully to treat malaria caused by Plasmodium falciparum. It had been assumed that differences between host and parasite in terms of the drug binding to dihydrofolate reductase-thymidylate synthase (DHFR-TS) were responsible for this success. But, in 19 April Science, Kai Zhang and Pradipsinh Rathod of University of Washington, Seattle, show that it may be differences in the regulation of DHFR between host and parasite that explai

Constant remodelling of bones — up to 10% of the total mass every year — helps to maintain the optimal levels of calcium in the blood and also the structural function of the skeleton, but the identity of the molecules involved in controlling this process remains unclear. In April 18 Nature, Hiroshi Takayanagi and colleagues from University of Tokyo show that interferon-β (IFN-β) is pivotal in regulating bone homeostasis (Nature 2002, 416:744-749).Takayanagi et al. observed

Parasitic nematode infections show a characteristic grouping among hosts, but the genes that predispose humans to these infections remain unknown. In April 16 online Proceedings of National Academy of Sciences, Sarah Williams-Blangero and colleagues from Southwest Foundation for Biomedical Research show that genes on chromosomes 1 and 13 are significant for the human infection with the roundworm Ascaris lumbricoides (Proc Natl Acad Sci USA 2002, 99:5533-5538).Williams-Blangero et al. performed a