Conservation of the central proline-rich (PxxP) motifs of human immunodeficiency virus type 1 Nef protein during the disease progression in two hemophiliac patients

AbstractThe nef gene is considered to play a crucial role in the development of acquired immunodeficiency syndrome (AIDS). In this study, we analyzed the sequence of nef quasispecies obtained from replication-competent HIV-1 isolates from two Japanese hemophiliac patients infected with HIV-1. At least 10 nef clones were isolated at each time point and a total of 75 individual nef quasispecies were sequenced. We observed a gradual increase in genetic diversity of the nef gene over time. Among the various functional regions of Nef protein, myristoylation site and the central PXXP (SH3 ligand) motifs were well conserved. The scattered regions responsible for downregulation of CD4 and class I MHC were also conserved. These data suggest that these functions of Nef may be involved throughout the disease process

Use of the Reverse Transcriptase Polymerase Chain Reaction for Diagnosis on Dengue Virus Infection Compared to IgM-ELISA

Applicability of the reverse transcriptase polymerase chain reaction (RT-PCR) was evaluated as a routine rapid diagnostic test for dengue virus infection. A total of 160 acute phase sera from patients with clinical diagnosis of dengue fever was examined both by the RT-PCR and IgM-ELISA. Of these, 9 (6%) were positive for both RT-PCR and IgM-ELISA, 61 were positive for IgM-ELISA only and 31 (19%) for RT-PCR only. Both techniques gave negative results in the remaining 59 (37%) specimens. The diagnostic efficiency of IgM-ELISA was statistically better than the RT-PCR even when the specimens were collected on the 3rd or 5th days of the disease. Considering the operational cost in the tests, the acute serum specimens should first be tested by the IgM-ELISA, followed by the RT-PCR on the negative specimens in order to increase the diagnostic efficiency with reasonable cost

Genotypes of Japanese Encephalitis Virus Isolated in Three States in Malaysia

Two hundred forty nucleotides from the pre-membrane gene region of 12 Japanese encephalitis virus (JEV) strains isolated from three different regions of Malaysia from 1993 to 1994 were sequenced and compared with each other and with the JEV strains from different geographic areas in Asia. These 12 Malaysian isolates were classified into two genotypes. The four JEV strains isolated from Sarawak in 1994 and the four JEV strains isolated from Sepang, Selangor in 1993 were classified into one genotype that included earlier isolated strains from Malaysia (JE-827 from Sarawak in 1968 and WTP/70/22 from Kuala Lumpur in 1970). The four JEV strains from Ipoh, Perak in 1994 were classified into another genotype that included JEV strains isolated from northern Thailand and Cambodia. In an earlier report, 10 JEV strains from Sabak Bernam, Selangor in 1992 were classified into the largest genotype that included strains isolated in temperate regions such as Japan, China, and Taiwan. The data indicate that at least three genotypes of JEV have been circulating in Malaysia