Amplification-free detection of microRNAs via a rapid microarray-based sandwich assay.

The detection and profiling of microRNAs are of great interest in disease diagnosis and prognosis. In this paper, we present a method for the rapid amplification-free detection of microRNAs from total RNA samples. In a two-step sandwich assay approach, fluorescently labeled reporter probes were first hybridized with their corresponding target microRNAs.

Plasmodium ovale curtisi and Plasmodium ovale wallikeri circulate simultaneously in African communities.

It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasite, Plasmodium ovale curtisi and Plasmodium ovale wallikeri. It was recently shown that these two parasite types are sympatric at the country level. However, it remains possible that localised geographic, temporal or ecological barriers exist within endemic countries which prevent recombination between the genomes of the two species.

Two nonrecombining sympatric forms of the human malaria parasite Plasmodium ovale occur globally.

Background: Malaria in humans is caused by apicomplexan parasites belonging to 5 species of the genus Plasmodium. Infections with Plasmodium ovale are widely distributed but rarely investigated, and the resulting burden of disease is not known. Dimorphism in defined genes has led to P.

Mutations in the Plasmodium falciparum cytochrome b gene are associated with delayed parasite recrudescence in malaria patients treated with atovaquone-proguanil.

Background: Fixed-dose combination antimalarial drugs have played an increasingly important role in the treatment and chemoprophylaxis of falciparum malaria since the worldwide failure of monotherapy with chloroquine. Atovaquone-proguanil is one such combination drug used both for prophylaxis in travellers, and for treatment of acute malaria cases in European hospitals and clinics.

Methods: A series of eight atovaquone-proguanil treatment failures and two prophylaxis breakthroughs from four UK hospitals from 2004-2008 were analysed for evidence of mutations in the pfcyt-b gene, previously found to be associated with failure of the atovaquone component.

Plasmodium malariae in Haitian refugees, Jamaica.

Since 1963, reported malaria transmission in Haiti has been restricted to Plasmodium falciparum. However, screening of Haitian refugees in Jamaica in 2004, by microscopic examination, identified P. falciparum, P.

Evaluation of the phosphorescent palladium(II)-coproporphyrin labels in separation-free hybridization assays.

Palladium(II)-coproporphyrin label and a set of corresponding monofunctional labeling reagents with different linker arms were evaluated for labeling of oligonucleotides and subsequent use in hybridization assays. The properties of resulting oligonucleotide probes including phosphorescence spectra, quantum yields, lifetimes, and labeling yields were examined as functions of the label and oligonucleotide structures. Upon hybridization with complementary sequences bearing dabcyl, QSY-7, and rhodamine green dyes, the probes displayed strong quenching due to close proximity effects.

Synthesis and evaluation of phosphorescent oligonucleotide probes for hybridisation assays.

Monofunctional, p-isothiocyanatophenyl-derivatives of platinum (II)-coproporphyrin-I (PtCP-NCS) were evaluated as phosphorescent labelling reagents for synthetic oligonucleotides containing a 3'- or 5'-amino modification. Synthesis and purification conditions were optimised to generate high yields and purity of PtCP-labelled oligonucleotide probes. Phosphorescent properties of the PtCP label have been shown to be largely unaffected by conjugation to oligonucleotides of various length, GC composition and label attachment site.