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The estimated 6000 species of Lycaenidae account for about one third of all Papilionoidea. The majority of lycaenids have associations with ants that can be facultative or obligate and range from mutualism to parasitism. Lycaenid larvae and pupae employ complex chemical and acoustical signals to manipulate ants. Cost/benefit analyses have demonstrated(More)
Sequence analysis of the region of the mumps virus genome encoding the putative small hydrophobic protein gene confirms that it is a highly variable region. Jeryl Lynn, the mumps vaccine strain used in the U.K., is shown to be a mixture of two closely related viruses, both probably of American origin.
BACKGROUND AND OBJECTIVES Twenty-two laboratories from nine countries participated in an international collaborative study to establish a World Health Organization (WHO) international standard for hepatitis B virus (HBV) DNA nucleic acid amplification techniques (NAT). MATERIALS AND METHODS Three samples, AA, BB (both of which were lyophilized) and CC(More)
BACKGROUND AND OBJECTIVES The aims of this study were the establishment of a WHO International standard for HCV RNA for nucleic acid amplification technology (NAT) assays and the determination of the HCV RNA content of the candidate standard. MATERIALS AND METHODS Twenty-two laboratories evaluated three candidate materials (two lyophilised, AA and BB,(More)
The nucleotide sequences of the SH gene of 45 new mumps virus isolates derived from different parts of Europe, Canada and USA were determined. A phylogenetic tree was constructed which confirmed the existence of three major clusters. While clustering according to geographical origin was clear in some cases each of the major clusters included isolates which(More)
Twenty-six laboratories from 10 different countries participated in a collaborative study to establish the 1st International Standard for HIV-1 RNA for use in nucleic acid-based techniques (NAT). Three candidate preparations were tested all based on genotype B viruses. The candidates were tested by each laboratory at a range of dilutions in four independent(More)
BACKGROUND AND OBJECTIVES Five HCV RNA reference reagents, the Paul Ehrlich Institut (PEI) reference 75, the National Institute for Biological Standards and Control (NIBSC) reagent 96/586, the Central Laboratory of the Netherlands Red Cross Blood Transfusion Service (CLB) Pelispy HCV RNA run control S2001, the Istituto Superiore di Sanità (ISS) reagent 0498(More)
The isolation of a capsid intertypic poliovirus recombinant from a child with vaccine-associated paralytic poliomyelitis is described. Virus 31043 had a Sabin-derived type 3-type 2-type 1 recombinant genome with a 5'-end crossover point within the capsid coding region. The result was a poliovirus chimera containing the entire coding sequence for antigenic(More)
BACKGROUND AND OBJECTIVES A collaborative study, involving 26 laboratories from 14 countries, was carried out in order to establish a World Health Organization (WHO) International Standard for human parvovirus B19 (B19) DNA nucleic acid amplification techniques (NAT). MATERIALS AND METHODS Four samples: AA, BB (which were lyophilized), CC and DD (which(More)
We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much(More)