High CD4(+) T-cell surface CXCR4 density as a risk factor for R5 to X4 switch in the course of HIV-1 infection.

For unclear reasons, about 50% of HIV-infected subjects harbour CXCR4-using (X4) viral strains in addition of CCR5-using (R5) viral strains at late stages of the disease. One hypothesis is that a low CD4(+) T-cell surface CCR5 density could facilitate the emergence of X4 strains. Alternatively, one could argue that a high CD4(+) T-cell surface CXCR4 density that is observed in individuals presenting with X4 strains, could favour R5 to X4 switch.

KI and WU polyomaviruses in children, France.

KI and WU Polyomaviruses in Children, France

Electron microscopy observation of human bocavirus (HBoV) in nasopharyngeal samples from HBoV-infected children.

The newly identified human bocavirus is frequently detected by molecular techniques in respiratory samples from children with respiratory tract infections, but virions have not been observed so far. We report the electron microscopy observation of viral particles in nasopharyngeal aspirates previously found to be positive for human bocavirus DNA. The virions presented the expected structural characteristics of a Parvoviridae family member.