BACKGROUND The formation of two distinctive cell lineages in preimplantation mouse embryos is characterized by differential gene expression. The cells of the inner cell mass are pluripotent and express high levels of Oct4 mRNA, which is down-regulated in the surrounding trophectoderm. In contrast, the trophectoderm of female embryos contains Xist mRNA, which is absent from cells of the inner ma...

Noroviruses (NoV), which are members of the family Caliciviridae, are the most important cause of outbreaks of acute gastroenteritis worldwide and are commonly found in shellfish grown in polluted waters. In the present study, we developed broadly reactive one-step TaqMan reverse transcription (RT)-PCR assays for the detection of genogroup I (GI) and GII NoV in fecal samples, as well as shellfi...

Acute meningitis is the most common neurologic disease that involves the central nervous system. The spectrum of infectious agents that cause neurologic infection is remarkably broad and numerous viruses are the most frequent cause of the aseptic meningitis syndrome. We applied a multiplex one-step method for the rapid detection of the genomic RNA of different neurotropic viruses: particles in ...

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis in people in many developing countries and is also endemic in many industrialized countries. Mammalian HEV (mHEV) isolates can be divided into at least four recognized major genotypes. Several nucleic acid amplification techniques have been developed for mHEV detection, with great differences in sensitivity. The aim of this study...

A new approach was developed for the rapid detection and identification of Brazilian alphaviruses and flaviviruses. The methodology involves the genus-specific detection of Alphavirus and Flavivirus by a duplex reverse transcription-PCR (D-RT-PCR), followed by multiplex nested PCR (M-N-PCR) or nested PCR (N-PCR) assays for species-specific identification. By this protocol, 25 arboviruses were s...

Reports of a novel influenza virus type A (H1N1), now designated by the World Health Organization as pandemic (H1N1) 2009, emerged from the United States and Mexico in April 2009. The management of the pandemic in Australia required rapid and reliable testing of large numbers of specimens for the novel influenza strain and differentiation from seasonal influenza strains. A real-time reverse tra...

Real-time polymerase chain reaction (RT-PCR) enables effective and sensitive screening for infectious risk in the field of blood safety. However, when using RT-PCR to detect bacterial contamination, several intractable points must be considered, one of which is the lack of appropriate quality control. In this study, we developed a simplified RT-PCR assay in which the same primer set and two dis...

The accepted model of retroviral reverse transcription includes a circular DNA intermediate which requires strand displacement synthesis for linearization and creation of an integration-competent, long terminal repeat-flanked DNA product. We have used an in vitro model of this last step of reverse transcription to examine the role of the viral enzyme, reverse transcriptase (RT), in displacement...