Revue scientifique et technique (International Office of Epizootics), 2003
A classification of neurological or neurologically expressed disorders that occur in Western Euro... more A classification of neurological or neurologically expressed disorders that occur in Western European cattle aged 12 month and over has been established on the basis of aetiology, frequency and conditions of appearance, age and type of animals concerned and the main clinical signs observed. Neurologically expressed disorders have been classified according to different groups of causes: biological, non-biological and non-specific or unknown. Differential diagnosis of neurologically expressed disorders is an essential element in the clinical epidemiological surveillance of bovine spongiform encephalopathy. A growing number of aetiologies are described in the scientific literature. The identification and centralised management of neurological disorders will make it possible, one the one hand, to take account of the inherent variability in the clinical forms encountered and in the diagnostic approaches of the observers and, on the other hand, to identify new risk factors in order to con...
An increase in honey bee mortality has been reported within and outside the European Union. A Bel... more An increase in honey bee mortality has been reported within and outside the European Union. A Belgian honey bee health monitoring was started in 2012 based on a standardized and pan-European voluntary surveillance program (EPILOBEE). The main objective was to estimate honey bee mortality during winter and the apicultural season using a harmonized survey. For the Belgian study, the guidelines were adapted according to small-scale Belgian beekeeping practices and previous pathogen prevalence studies. A two-stage sampling stratified by province resulted in 150 apiaries selected from a sampling frame of approximately 3,000 registered beekeepers. These apiaries were visited twice, questionnaires were completed, collecting information on risk factors and mortality. Samples systematically taken in autumn were screened / quantified for Varroa destructor mites. Weighted colony winter mortality rates were estimated per individual apiary and for geographical entities. We then attempted to identify risk factors in a case-control data interpretation, with observed mortality as a binary dependent variable. Questionnaire variables were evaluated in univariable logistic regression. The final multivariable model was retained: age of beekeeper, wanting to continue beekeeping, increasing number of surrounding landscapes, average colony varroa infestation level, all associated with increased mortality. Chemical acaricide treatment before 1 September and Thymol-containing acaricide were associated with lower mortality. The predictive accuracy of this final model was estimated by the area under the curve (AUC) and was 80.70%. The final predicted mortality risk was visualized on a map as an interpolated layer and compared with the observed mortality; clusters of high/low mortality were identified. This analysis has generated further hypotheses and highlighted where the case-control study could benefit from increased sample size.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine, 2000
Melanocytic tumours are a well-known clinical and pathological entity in horses, but further phen... more Melanocytic tumours are a well-known clinical and pathological entity in horses, but further phenotypic characterization of these tumours is lacking. Six melanocytic tumours from five horses (two metastatic and four benign) were examined by Ki67, PCNA and p53 immunostaining, DNA nick end labelling (Tunel) and Feulgen staining. The stainings were evaluated using quantitative image analysis. The resulting parameters of growth fraction (Ki67), S-phase index (PCNA), p53 index, apoptotic index, DNA index, nuclear diameter, ploidy balance, proliferation index (Feulgen) and hyperploidy were analysed. The metastatic melanomas showed overexpression of p53 in a large portion of the cells. Apoptosis was also found in the metastatic melanomas. No differences were found in growth fraction, S-phase index (PCNA) nor in DNA configuration between the metastatic and the benign tumours. No immunohistochemical evidence of mutant p53 could be found in the tumours. In conclusion, melanocytic tumours in h...
... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D.... more ... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D. & SILVA, A. C.(1997) Outbreak of cryptosporidiosis in dairy goats in Brazil. Veterinary Record 140,427-428 *SHORT COMMUNICATIONS Immunohistochemical ...
During two consecutive years Canada geese (Branta Canadensis) and small numbers of cross-bred gee... more During two consecutive years Canada geese (Branta Canadensis) and small numbers of cross-bred geese were caught at 3 different locations in Flanders from the end of June to the beginning of July, in their moulting period. Cloacal swabs (n = 564) were collected and stored in Hank’s solution at -80°C for the 2005 samples and at -4°C for the 2006 samples.The samples were analysed by real-time reverse transciption-polymerase chain reaction (RRT-PCR) for the detection of influenza A viruses. Serum samples (n = 423) were collected from the V.basilica and specific antibody titers against H5 and H7 subtypes of avian influenza A virus were determined by a hemagglutination inhibition (HI) test following standard procedures (Council directive 92/40 EEC). Additionally 325 serum samples were subjected to an IgG ELISA test for the detection of antibodies against avian influenza M2e antigen. M2e is an influenza A virus induced cell membrane protein that is abundant on virus infected cells. All of ...
... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D.... more ... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D. & SILVA, A. C.(1997) Outbreak of cryptosporidiosis in dairy goats in Brazil. Veterinary Record 140,427-428 *SHORT COMMUNICATIONS Immunohistochemical ...
Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophag... more Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays.
Revue scientifique et technique (International Office of Epizootics), 2003
A classification of neurological or neurologically expressed disorders that occur in Western Euro... more A classification of neurological or neurologically expressed disorders that occur in Western European cattle aged 12 month and over has been established on the basis of aetiology, frequency and conditions of appearance, age and type of animals concerned and the main clinical signs observed. Neurologically expressed disorders have been classified according to different groups of causes: biological, non-biological and non-specific or unknown. Differential diagnosis of neurologically expressed disorders is an essential element in the clinical epidemiological surveillance of bovine spongiform encephalopathy. A growing number of aetiologies are described in the scientific literature. The identification and centralised management of neurological disorders will make it possible, one the one hand, to take account of the inherent variability in the clinical forms encountered and in the diagnostic approaches of the observers and, on the other hand, to identify new risk factors in order to con...
An increase in honey bee mortality has been reported within and outside the European Union. A Bel... more An increase in honey bee mortality has been reported within and outside the European Union. A Belgian honey bee health monitoring was started in 2012 based on a standardized and pan-European voluntary surveillance program (EPILOBEE). The main objective was to estimate honey bee mortality during winter and the apicultural season using a harmonized survey. For the Belgian study, the guidelines were adapted according to small-scale Belgian beekeeping practices and previous pathogen prevalence studies. A two-stage sampling stratified by province resulted in 150 apiaries selected from a sampling frame of approximately 3,000 registered beekeepers. These apiaries were visited twice, questionnaires were completed, collecting information on risk factors and mortality. Samples systematically taken in autumn were screened / quantified for Varroa destructor mites. Weighted colony winter mortality rates were estimated per individual apiary and for geographical entities. We then attempted to identify risk factors in a case-control data interpretation, with observed mortality as a binary dependent variable. Questionnaire variables were evaluated in univariable logistic regression. The final multivariable model was retained: age of beekeeper, wanting to continue beekeeping, increasing number of surrounding landscapes, average colony varroa infestation level, all associated with increased mortality. Chemical acaricide treatment before 1 September and Thymol-containing acaricide were associated with lower mortality. The predictive accuracy of this final model was estimated by the area under the curve (AUC) and was 80.70%. The final predicted mortality risk was visualized on a map as an interpolated layer and compared with the observed mortality; clusters of high/low mortality were identified. This analysis has generated further hypotheses and highlighted where the case-control study could benefit from increased sample size.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine, 2000
Melanocytic tumours are a well-known clinical and pathological entity in horses, but further phen... more Melanocytic tumours are a well-known clinical and pathological entity in horses, but further phenotypic characterization of these tumours is lacking. Six melanocytic tumours from five horses (two metastatic and four benign) were examined by Ki67, PCNA and p53 immunostaining, DNA nick end labelling (Tunel) and Feulgen staining. The stainings were evaluated using quantitative image analysis. The resulting parameters of growth fraction (Ki67), S-phase index (PCNA), p53 index, apoptotic index, DNA index, nuclear diameter, ploidy balance, proliferation index (Feulgen) and hyperploidy were analysed. The metastatic melanomas showed overexpression of p53 in a large portion of the cells. Apoptosis was also found in the metastatic melanomas. No differences were found in growth fraction, S-phase index (PCNA) nor in DNA configuration between the metastatic and the benign tumours. No immunohistochemical evidence of mutant p53 could be found in the tumours. In conclusion, melanocytic tumours in h...
... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D.... more ... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D. & SILVA, A. C.(1997) Outbreak of cryptosporidiosis in dairy goats in Brazil. Veterinary Record 140,427-428 *SHORT COMMUNICATIONS Immunohistochemical ...
During two consecutive years Canada geese (Branta Canadensis) and small numbers of cross-bred gee... more During two consecutive years Canada geese (Branta Canadensis) and small numbers of cross-bred geese were caught at 3 different locations in Flanders from the end of June to the beginning of July, in their moulting period. Cloacal swabs (n = 564) were collected and stored in Hank’s solution at -80°C for the 2005 samples and at -4°C for the 2006 samples.The samples were analysed by real-time reverse transciption-polymerase chain reaction (RRT-PCR) for the detection of influenza A viruses. Serum samples (n = 423) were collected from the V.basilica and specific antibody titers against H5 and H7 subtypes of avian influenza A virus were determined by a hemagglutination inhibition (HI) test following standard procedures (Council directive 92/40 EEC). Additionally 325 serum samples were subjected to an IgG ELISA test for the detection of antibodies against avian influenza M2e antigen. M2e is an influenza A virus induced cell membrane protein that is abundant on virus infected cells. All of ...
... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D.... more ... Infection and Immunity 30, 884-886 VIEIRA, L. S., SILVA, MB O., TOLENTINO, A. CV, LIMA, J. D. & SILVA, A. C.(1997) Outbreak of cryptosporidiosis in dairy goats in Brazil. Veterinary Record 140,427-428 *SHORT COMMUNICATIONS Immunohistochemical ...
Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophag... more Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays.
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