Phylogenetic analysis of WNV in North American blood donors during the 2003-2004 epidemic seasons.

West Nile Virus (WNV) collected from 179 human blood donors in 25 US states and three Canadian provinces during the 2003 and 2004 epidemic seasons were genetically analyzed. The evolution of WNV during its Western spread was examined by envelope (E) gene sequencing of all 179 cases and full open reading frame sequencing of a subset of 20 WNV to determine if geographic and temporal segregation of distinct viral variants had occurred. Median joining network analysis was used to examine the genetic relationship between E gene variants and identified four large genetic clusters showing the gradual accumulation of mutations during the virus' western expansion.

West Nile virus in Canadian blood donors.

Background: Blood donation screening for West Nile virus (WNV) RNA by nucleic acid testing (NAT) was implemented in Canada in July 2003, and 14 WNV RNA-positive donations were identified. Samples were screened in minipools of six donations with a WNV assay (TaqScreen, Roche). Two of the donors were identified by single-donor screening that was initiated in the province of Saskatchewan, which had the highest prevalence of WNV in the country, in early September 2003.

Founder von Willebrand factor haplotype associated with type 1 von Willebrand disease.

To date, no dominant mutation has been identified in a significant proportion of patients with type 1 von Willebrand disease (VWD). In this study, we examined 70 families as part of the Canadian Type 1 VWD Study. The entire VWF gene was sequenced for 1 index case, revealing 2 sequence variations: intron 30 (5312-19A>C) and exon 28 at Tyr1584Cys (4751A>G).

The canine factor VIII 3'-untranslated region and a concatemeric hepatocyte nuclear factor 1 regulatory element enhance factor VIII transgene expression in vivo.

If gene therapy is to be an effective treatment modality for hemophilia A, therapeutic levels and tissue-restricted expression of factor VIII (FVIII) must be achieved through optimization of transgene expression. To this end, we incorporated three types of sequence elements into a canine B domain-deleted FVIII transgene cassette and individually evaluated their effect on FVIII transgene expression. Functional FVIII activity was initially assessed in vitro and hydrodynamic injection of the different transgene constructs into mice was subsequently used as a model to compare in vivo expression of the various modified transgenes.

Aberrant splicing and premature termination of transcription of the FVIII gene as a cause of severe canine hemophilia A: similarities with the intron 22 inversion mutation in human hemophilia.

We have identified the causative mutation in the hemophilia A dog colony at Queen's University, Canada and have observed a striking similarity with the intron 22 inversion found in approximately 45% of severely affected hemophilia A patients. The canine hemophilia A phenotype arises from aberrant splicing and premature termination of transcription of the FVIII gene, resulting in a polyadenylated transcript lacking exons distal to 22 and terminating with a novel sequence element (NSE). In dogs and other species including humans, this NSE is present in low copy number.