Detection of HSV1 DNA by in situ hybridisation in human brain after immunosuppression.

Human brain cells were examined for the presence of herpes simplex virus type 1 (HSV1) DNA sequences by in situ hybridisation. Viral genome was detected in immunosuppressed patients with virological evidence of past HSV infection but not in immunosuppressed patients with no such evidence. In patients who had not been immunosuppressed, no HSV DNA sequences were detectable.

Virus infections in immunocompromised patients: their importance and their management.

Opportunistic viral infections were investigated in 156 adult patients admitted over one year to a medical oncology service: 35% of the total group and 65% of those with acute leukaemia experienced viral infections, 79% of which were with viruses of the herpes group. Surprisingly few enteric viruses were recovered. Reactivation of herpes simplex virus in the brains of these immunosuppressed patients was suggested by the demonstration by nucleic acid hybridization of herpes simplex virus DNA sequences in neurones and endothelial cells in patients with evidence of past infection with virus.

An improved method for preparing DNA from human brain.

The preparation of DNA from human brain by conventional protease and RNAase digestion, phenol-chloroform extraction and ethanol precipitation results in very low yields. This is probably due to interference by lipid present at very high levels in this tissue. We have overcome this by solubilizing the initial tissue homogenate by heating at 60 degrees C for 30 min in sodium dodecyl sulphate.