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Biomedical subjects

S Ciulli

Publications and source records attributed to S Ciulli.

12 recordsLinked to original sources
PubMed2006

Temperature-dependency of Betanodavirus infection in SSN-1 cell line.

This study examined the in vitro effects of temperature on Betanodavirus infection in the SSN-1 cell line. A Betanodavirus isolated from moribund sea bass fry Dicentrarchus labrax farmed in the Adriatic Sea and characterised as a RGNNV (Redspotted Grouper Nervous Necrosis Virus) genotype was used. Virus-infected SSN-1 cells were incubated at temperatures between 10 and 30 degrees C and observed for cytopathic effects daily for 15 d. Cell-free and cell-associated viral growth were evaluated by 50% tissue culture infectious dose (TCID50) titration at 0, 24, 48, 72, 96, 144, 192, 240, 312 and 360 h post-infection. Virus replication was observed at all temperatures from 15 to 30 degrees C. The optimal temperature for virus growth was 25 degrees C. A temperature of 10 degrees C was detrimental to the growth of the SSN-1 cells and cell death interfered with interpretations of viral growth. The isolate of Betanodavirus from Italian sea bass in this study demonstrates a different temperature range for growth compared to previous reports for related Betanodavirus strains, most likely due to an adaptation to the normal environmental temperatures of the host fish species of origin.

Animals↗
PubMed2006

A real time PCR assay for the detection and quantification of orf virus.

A real time quantitative PCR assay based on TaqMan technology was developed for orf virus (ORFV) DNA quantification in clinical samples, infected cells and organotypic cultures. This method was based on the amplification of a 70 bp fragment from the ORFV B2L gene (orthologue of the Vaccinia virus Copenhagen F13L gene) that encodes the major envelope protein. Both intra- and inter-assay variability were well within +/-0.25 log(10) S.D. showing the high efficiency and reproducibility of the assay. The TaqMan PCR was subsequently used to determine the titre of several batches of the ORFV strain NZ-2, with it being possible to quantify virus solutions in the range of 1 x 10(1) to 1 x 10(6) TCID(50)/ml. A good correlation between the titre determined by the TaqMan PCR and by conventional endpoint dilution was found. The PCR assay is reproducible and can be used for a rapid quantification of ORFV in vitro and ex vivo, being readily achievable within 1h.

Animals↗
PubMed2004

Heparin binding activity of orf virus F1L protein.

The orf virus is the type species of the Parapoxvirus genus and is the causative agent of contagious echtyma, a debilitating skin disease of sheep and goats, which can also affect man. The virus exhibits a restricted host range, even if it has been shown to bind to a wide range of tissues of non-permissive species. This ability is an argument for its potential use as an expression vector. Since most mammalian cell types express heparan sulfate (HS) surface receptors, we assumed that HS could serve as receptors to mediate orf virus binding. In this study, we showed that orf virus is inhibited by the addition of soluble heparin in cell cultures. Affinity chomatography using heparin agarose demonstrated that orf virus F1L is the major heparin binding protein. Furthermore, the recombinant F1L protein was visualised on the cell surface by confocal microscopy, and rabbits immunised with recombinant F1L protein produced virus neutralising antibodies. These results confirm that the F1L immunodominant protein is also involved in virus binding to cells as for the vaccinia homologue H3L protein. Heparin also inhibited the binding of the F1L protein to cells showing that this protein has a role in the early stages of infection.

Antibodies, Viral↗
PubMed2004

Diagnosis of orf virus infection in humans by the polymerase chain reaction.

The orf virus is the causal agent of contagious ecthyma in goats and sheep. The infection can be transmitted to humans and represents a typical example of occupational zoonosis. In Italy, the incidence of human infection remains uncertain because the disease is rarely reported or diagnosed. In this paper, we report a case of human orf virus infection and the laboratory methods of diagnosis. We demonstrated a genomic identity between the conserved and the variable regions of the genome of the viral strains isolated from the human patient and from the infected sheep confirming that there is no specific clone infecting humans rather than animals.

Adult↗
PubMed2002

Characterisation of immunodominant protein encoded by the F1L gene of orf virus strains isolated in Italy.

We analysed the molecular properties of the immunodominant protein of different orf virus strains isolated in Italy. The F1L encoding genes and the deduced amino acid sequences of all strains were determined and compared, and they showed several mutations. Structural analysis was carried out in order to assess the influence of amino acid variations on protein structure demonstrating a conservation of the secondary structure. Western blot analysis and immunogold electron microscopy showed that all orf virus strains were antigenically identical. The results of our study confirmed the immunogenicity of the F1L protein; furthermore, our data suggest a possible involvement of the protein in the virus cycle.

Amino Acid Sequence↗
PubMed1996

Some boundary problems in electrical impedance tomography.

Accurate mathematical modelling is important in the development of iterative image reconstruction algorithms for electrical impedance tomography (EIT). In such schemes the forward problem of calculating the electric potential from Neumann boundary data is solved many times. One aspect of this problem which has received some attention is the mathematical modelling of the electrodes used in the technique. In this paper we describe an integral equation formulation of a boundary value problem associated with this tissue and we indicate some of the ways in which this formulation can be used to obtain numerical and analytic results.

Algorithms↗
PubMed1995

Singularities of mixed boundary value problems in electrical impedance tomography.

The importance of accurate mathematical modelling in the development of image reconstruction algorithms for electrical impedance tomography (EIT) has been discussed in a number of recent papers. It is particularly important in iterative reconstruction schemes where the forward problem of calculating the electric potential from Neumann boundary data is solved many times. One area which needs to be considered it the mathematical modelling of the electrodes used in the technique. In this paper we discuss one of the more sophisticated models which has been proposed and present the results of a number of numerical and analytic calculations which we have made as a contribution to the understanding of this question.

Electric Impedance↗