Transmission of the 263K scrapie strain by the dental route.

Apart from a few cases of iatrogenic and familial human transmissible spongiform encephalopathies (TSEs) or prion diseases, the cause of Creutzfeldt-Jakob disease (CJD) remains unknown. In this paper we investigated the possibility that dental procedures may represent a potential route of infection. This was assessed by using the experimental model of scrapie in hamster.

Temporal mapping of transcripts in human herpesvirus-7.

Transcription of human herpesvirus-7 (HHV-7) in cultures of productively infected T-cells was studied. Transcription of HHV-7 was regulated by the typical herpesvirus cascade in which alpha, beta and gamma genes are sequentially transcribed. Transcripts of U10, U14, U18, U31, U39, U41, U42, U53, U73 and U89/90 were detected 3 h after infection and were not inhibited by the absence of protein synthesis and therefore were alpha functions.

'Primer alignment-and-extension': a novel mechanism of viral RNA recombination responsible for the rescue of inactivated poliovirus cDNA clones.

In the course of experiments designed to assess the potential role of alternative open reading frames (ORF) present in the 5'-terminal untranslated region (5'-UTR) of poliovirus type 1 (Mahoney strain) genomic RNA, we came across a double mutation that completely abrogated the infectivity of full-length cDNA clones. The infectivity was rescued in trans by cotransfecting COS-1 cells with short RNA transcripts of the wild-type 5'-UTR of poliovirus type 2 Lansing, provided a free 3'-OH was available. Direct sequencing of the viral RNA revealed that the infectious viruses recovered were recombinants Lansing/Mahoney, with variable points of 'crossing-over'.

Preserving the Identity of Small Settlements during Post-Disaster Reconstruction in Italy(1).

The nature of small, historic settlements in Apennine Italy is described and options for reconstructing them are discussed. Villages and towns are disproportionately vulnerable to damage by even small earthquakes, which can cause substantial changes to their distinctive character. Responses to such events are outlined, including various strategies of evacuation and the process of developing standardized methods for post-disaster architectural survey.