Biomedical subjects

R Cottone

Publications and source records attributed to R Cottone.

10 recordsLinked to original sources

PubMed2003

Relatedness and heterogeneity at the near-terminal end of the genome of a parapoxvirus bovis 1 strain (B177) compared with parapoxvirus ovis (Orf virus).

The present study provides for the first time an extended investigation of individual genes located at the near-terminal right end of the genome of parapoxvirus bovis 1, Bovine papular stomatitis virus (BPSV) strain B177 and Orf virus (ORFV). Comparison of the respective DNA sequences of ORFV strain D1701 (9.9 kbp) and BPSV B177 (7.7 kbp) revealed a very similar organization of closely related genes transcribed in a rightward orientation. The most salient findings of this study were: (i) the absence of the ORFV-specific vascular endothelial growth factor (VEGF-E) gene in the BPSV isolate; (ii) the presence of an interleukin-10 (IL-10) orthologue; and (iii) the detection of three new genes encoding ankyrin-repeat-containing polypeptides. These results not only contribute to potential improvements of future molecular differentiation between the parapoxvirus species, but also shed new light on different pathobiologies among parapoxviruses.

Amino Acid Sequence↗

PubMed2002

Orf virus encodes a functional dUTPase gene.

The present study is the first report on the functional activity of a parapoxvirus-encoded dUTPase. The dUTPase gene of the attenuated orf virus (ORFV), strain D1701, was expressed as a bacterial thioredoxin fusion protein. In vitro assays showed that ORFV dUTPase was highly specific for dUTP as substrate. The enzyme was active over a broad pH range (pH 6.0-9.0), with maximal enzymatic activity at pH 7.0 in the presence of Mg(2+) cations. Kinetic studies of the recombinant ORFV dUTPase revealed an apparent K(m) of 4.0 microM, which is more similar to that of the mammalian or African swine fever virus enzyme than to the K(m) of vaccinia virus dUTPase. Enzyme activity was also found with purified ORFV particles, indicating its virion association.

Deoxyuracil Nucleotides↗

PubMed2000

Generation of recombinant parapoxviruses: non-essential genes suitable for insertion and expression of foreign genes.

Orf virus (OV) is an epitheliotropic poxvirus and belongs to the genus Parapoxvirus (PPV). PPV, especially OV, is regarded as a promising candidate for an expression vector. Among available live vaccines only strain D1701 represents a highly attenuated OV strain with clearly reduced pathogenicity. Therefore, we started to identify potentially non-essential genes or regions of D1701, which might be suitable for insertion and expression of foreign genes. The present contribution reviews some of the progress using the vegf-e (homologue of the mammalian vascular endothelial growth factor) gene locus for the generation of recombinant D1701. The vegf-e gene of D1701 is dispensable for virus growth in vitro and in vivo, and represents a major virulence determinant of OV. It is shown that foreign genes can be inserted and functionally expressed in the vegf-e locus, also leading to the induction of a specific immune response in the non-permissive host. Furthermore, it is reported that adaptation to VERO cells led to the deletion of three further regions of the OV D1701 genome, which seems to be combined with additional virus attenuation in sheep. Molecular analysis of this OV D1701 variant allows the identification of new, potentially non-essential sites in the viral genome.

Animals↗

PubMed1999

Parapoxviruses: potential alternative vectors for directing the immune response in permissive and non-permissive hosts.

Parapoxvirus (PPV) represents a genus of the poxviridae, and particularly PPV ovis (Orf virus, OV) seems to offer several potential advantages for the use of vector vaccine. Therefore, we started to investigate the genome of the highly attenuated OV strain D1701, which was only poorly characterised until now. Due to recombination of non-homologous sequences, part of the right hand end of the D1701 genome was duplicated and translocated to the opposite end of the genome. As a consequence gene deletion had occurred and the inverted terminal repeat region is increased. Results are described to identify viral genes, which are non-essential for virus replication and potentially influence viral pathogenesis, virulence, and host immunity. In more detail, we analysed the expression and functional activity of the OV-specific vascular endothelial growth factor (VEGF) gene homologue. Finally the construction and production of a D1701 mutant lacking the VEGF gene homologue is reported.

Animals↗

PubMed1998

Analysis of genomic rearrangement and subsequent gene deletion of the attenuated Orf virus strain D1701.

The orf virus (OV) strain D1701 belongs to the genetically heterogenous parapoxvirus (PPV) genus of the family Poxviridae. The attenuated OV D1701 has been licensed as a live vaccine against contagious ecthyma in sheep. Detailed knowledge on the genetic structure and organization of this PPV vaccine strain is an important prerequisite to reveal possible genetic mechanisms of PPV attenuation. The present study demonstrates a genomic map of the approximately 158 kbp DNA of OV D1701 established by hybridization studies of cloned restriction fragments covering the complete viral genome. The results show an enlargement of the inverted terminal repeats (ITR) to up to 18 kbp due to recombination between nonhomologous sequences during cell culture adaptation. DNA sequencing of the region adjacent to the ITR junction revealed the absence of one open reading frame designated E2L. In contrast to a transposition-deletion variant of the New Zealand OV strain NZ2 (Fleming et al., 1995) the two genes E3L (a homologue of dUTPase) and G1L neighbouring E2L are retained in OV D1701. DNA and RNA analyses proved the presence of E2L gene in wild-type OV isolated directly from scab material. The data presented indicate that the E2L gene is nonessential for virus replication in vitro and in vivo, and may represent one important viral gene in determining virulence and pathogenesis of OV.

Amino Acid Sequence↗

PubMed1991

Multicenter study of superficial bladder cancer treated with intravesical bacillus Calmette-Guerin or adriamycin. Results of long-term follow-up.

We evaluated 158 cases of patients with superficial bladder cancers (Stages Ta, T1, and Tis). These cases were treated with either intravesical bacillus Calmette-Guerin (BCG) (Tice strain) or Adriamycin (ADR), in a multicenter, nonrandomized study. One hundred thirty-one of these patients were followed up; the results continue to show a higher percentage of initial complete remissions with BCG (68%) than with ADR (57%). With additional therapy, both BCG and ADR achieved complete remission in 83 percent of the patients. When 7 failures with patients taking ADR were switched to BCG and the disease cleared, the rate of complete remission for BCG rose to 85 percent. The recurrence rate per 100 patient-months was only slightly different for BCG (0.9) and ADR (0.8). The percentage of progressions continued to be higher for BCG (8%) than for ADR (5%). Cystectomies were performed in 2.5 percent of the BCG patients. Using the Cox regression model with covariates, we found drug treatment, tumor grade, and sex to be statistically significant in determining failures throughout the protocol. Although both BCG and ADR were effective over the course of the study, BCG is the drug of choice for residual tumor (Stages T1 and Tis).

Administration, Intravesical↗

PubMed1990

Multicenter study of superficial bladder cancer treated with intravesical bacillus Calmette-Guérin or adriamycin.

We evaluated 155 patients with superficial bladder cancers (Stages Ta, T1, and TIS) and treated them with either intravesical bacillus Calmette-Guérin (Tice strain) (BCG) or doxorubicin hydrochloride (Adriamycin), in a multicenter nonrandomized study. At present 140 of these patients in treatment Groups I and II are being followed up. With additional follow-up, BCG continued to produce a higher percentage of complete remissions (71%) than doxorubicin (54%). The percentage of incomplete remission with BCG (7%) was half that with doxorubicin (14%). Half of the patients whose initial therapy failed had complete remission after additional therapy. However, for patients with recurrence, additional follow-up shows a recurrence rate per 100 patient-months for BCG (1.0) only slightly lower than that for doxorubicin (1.1). The percentage of progressions continued to be higher with BCG (8.5%) than with doxorubicin (5%), but the difference between these results for the two drugs proved slightly less than we reported previously. Of the patients in this study, 2.5 percent (all treated with BCG) required cystectomy. A comparison of the results of our study with those of 13 other studies using BCG to treat bladder cancer indicates that therapy beyond an initial course of 6 weekly treatments increases the percentage of complete response. All of the studies showed that the greatest improvement in percentage of complete response occurred with the second course of treatment. The value of maintenance therapy cannot yet be determined, since few studies have used that protocol. The percentage of patients requiring cystectomy in studies with fewer than 20 treatments was 2.2 times higher than in studies with more than 20 treatments.

Administration, Intravesical↗

PubMed1988

Superficial bladder cancer treated with intravesical bacillus Calmette-Guérin or adriamycin: follow-up report.

We evaluated 139 patients with superficial bladder cancer (Stages Ta, Tl, and TIS) and treated them with either intravesical bacillus Calmette-Guérin, Tice strain (BCG), or doxorubicin hydrochloride (Adriamycin [ADR]) in a nonrandomized, multicenter study. Our follow-up study comprises 135 of these patients. Of these patients, 78 tumors were completely resected, and 61 were incompletely resected. When a proportional-hazards model (Cox) was applied, there was a statistically significant difference between the recurrence rates for the two drugs. On the basis of recurrence rates per 100 patient-months, both BCG (1.2) and ADR (0.9) worked well with completely resected tumors. However, for incomplete resections, the recurrence rate for BCG (0.9) was less than half that for ADR (1.9). The overall recurrence rates were 1.1 and 1.3 for BCG and ADR, respectively. There have been 42 failures of treatment with either BCG or ADR. We defined failure as any recurrence of tumor; progression of the cancer in stage, grade, tumor number or size; or any residual tumor after 18 treatments (14 months of therapy). As to the failures in patients whom we followed up, and whose treatment was either switched from ADR to BCG or continued on further BCG treatment, 53 per cent have achieved complete remission. Complete remission for BCG and ADR were 76 per cent and 52 per cent, respectively. Of the various factors considered in the study, only tumor grade and treatment drug were statistically significant. The cystectomy rate was 1 per cent for BCG-treated patients and 0 for ADR-treated patients.

Administration, Intravesical↗

PubMed1988

Does bacillus Calmette-Guérin immunotherapy accelerate growth and cause metastatic spread of second primary malignancy?

In our study, 29 of 150 patients with bladder cancer also had other associated primary malignancies, 10 of which were manifested after intravesical treatment with bacillus Calmette-Guérin (BCG). Second primary malignancies developed in 5 of these patients within three months of the start of BCG therapy. All 5 showed acceleration of the second primary tumor, and distant metastatic lesions developed in 4. In the other 5 patients nonbladder primary malignancies developed eight months or more after intravesical BCG therapy started, but did not show acceleration or spread. Twenty patients with other primary malignancies that had developed months to years before intravesical therapy did not show acceleration or spread of those tumors. We have seen enough cases of patients who received intravesical BCG at the time of growth and spread of second primary malignancies to warrant concern. Animal and human studies of BCG use for treatment of malignancy indicate that the temporal relationship between the starting point of tumor development and the starting point of BCG treatment is crucial in determining whether BCG will eradicate or exacerbate the tumor. We have therefore instituted a change in our treatment until the question of whether or not BCG causes the appearance and spread of these second malignancies is answered.

Administration, Intravesical↗

PubMed1987

Superficial bladder cancer treated by intravesical bacillus Calmette-Guerin or adriamycin: multicenter study interim report.

One hundred sixteen patients with superficial bladder cancers (Stages Ta, T1, and TIS) were evaluated and treated with either intravesical bacillus Calmette-Guerin [Tice strain] (BCG) or doxorubicin hydrochloride (Adriamycin [ADR]), in a multicenter study. One hundred nine of these patients currently have follow-up. Of these, 54 were completely resected and 55 incompletely resected. For complete resections, based on recurrence rates per 100 patient months, both BCG (0.22) and ADR (0.91) worked well, although BCG had a slightly lower recurrence rate. However, for incomplete resections, BCG (0.20) had a markedly lower recurrence rate than ADR (2.52). Eighteen patients failed initial treatment, with either BCG or ADR. All have been placed on long-term therapy schedules. Of the 12 failures who currently have follow-up, 11 (92%) have either partially or completely responded with additional intravesical therapy. No patients in this study have yet required cystectomies.

Administration, Intravesical↗