Point prevalence of gastrointestinal parasites in double purpose cattle of Rio de Oro and Aguachica municipalities, Cesar state, Colombia.

Gastrointestinal parasites are one of the most important health problems in cattle worldwide, as they cause economic losses in the herds. Twenty - seven double purpose herds were visited to determine the prevalence of gastrointestinal parasites in cattle at the Rio de Oro and Aguachica municipalities. Overall, 862 fecal samples were collected in three age groups: <12months, 12-24months and >24months.

Beach litter and woody-debris colonizers on the Atlantico department Caribbean coastline, Colombia.

Some marine invertebrates can inhabit floating substrates, and raft over long distances, becoming a significant environmental problem in terms of alien species and habitat disruption. On the Atlantico Department beaches (Colombia) woody debris and plastic litter dominate (86%) the types of refuse on the beaches with their densities ranging from 0.82-1.

The polypyrimidine tract binding protein is required for efficient picornavirus gene expression and propagation.

Mammalian host factors required for efficient viral gene expression and propagation have been often recalcitrant to genetic analysis. A case in point is the function of cellular factors that trans-activate internal ribosomal entry site (IRES)-driven translation, which is operative in many positive-stranded RNA viruses, including all picornaviruses. These IRES trans-acting factors have been elegantly studied in vitro, but their in vivo importance for viral gene expression and propagation has not been widely confirmed experimentally.

Activity of a type 1 picornavirus internal ribosomal entry site is determined by sequences within the 3' nontranslated region.

We have proposed a cancer treatment modality based on poliovirus chimeras replicating under the translational control of an internal ribosomal entry site (IRES) derived from human rhinovirus type 2. Insertion of the heterologous IRES causes a neuron-specific propagation deficit and eliminates neurovirulence inherent in poliovirus without affecting viral growth in cells derived from malignant gliomas. We now report the elucidation of a molecular mechanism responsible for the cell type-specific defect mediated by the rhinovirus IRES.

Structural determinants of insert retention of poliovirus expression vectors with recombinant IRES elements.

Although picornaviruses provide attractive vectors for expression of foreign genes, poor genetic stability restricts their use for immunization purposes. A new prototype vector was generated to increase foreign insert retention, by shifting of the initiation codon to a cryptic AUG within the internal ribosomal entry site (IRES) and replacement of IRES domain VI with foreign ORFs. Using our strategy to replace regulatory noncoding sequences with unrelated foreign genetic material, we generated stable poliovirus-based expression vectors with robust long-term expression of foreign ORFs.