The Experts below are selected from a list of 93 Experts worldwide ranked by ideXlab platform
F. Jackson - One of the best experts on this subject based on the ideXlab platform.
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effects of strategic anthelmintic treatments on the milk production of dairy sheep naturally infected by gastrointestinal strongyles
Veterinary Parasitology, 2008Co-Authors: Giuseppe Cringoli, F. Jackson, Vincenzo Veneziano, Jozef Vercruysse, A W Greer, V Fedele, Laura Mezzino, Laura RinaldiAbstract:The present paper was aimed at assessing the benefit of strategic anthelmintic treatments on milk production in four commercial dairy sheep farms in Southern Italy whose animals were naturally infected by gastrointestinal (GI) strongyles and Dicrocoelium dendriticum. The scheme was based on two treatments timed in relationship to parturition, i.e. the first with moxidectin in the periparturient period and the second with Netobimin at the mid/end of lactation. On each farm, two similar groups (20 animals each) were formed, one untreated control group and one group treated according to the above-mentioned scheme. Faecal egg counts (FEC) were performed on each study animal at the start of the trial and then monthly until the end of the study; in addition, milk production was recorded for each animal fortnightly in each farm for the lactation period. The results showed a significant increase in milk yield across all four farms that ranged from 19% to 44% improvement in milk yield. The benefit in milk yield in addition to considerably reduced egg output of the treated animals provide clear evidence that the two main aims of prophylactic parasite control, i.e. to maintain or improve animal performance and to reduce pasture contamination, can be achieved using strategic anthelmintic treatments.
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the pharmacokinetics of albendazole metabolites following administration of albendazole albendazole sulfoxide and Netobimin to one month and eight month old sheep
International Journal for Parasitology, 1995Co-Authors: Quintin Mckellar, Robert L. Coop, F. JacksonAbstract:Abstract The principal metabolites detected in plasma of sheep following oral administration of albendazole (ABZ), albendazole sulfoxide (ABSO) and Netobimin (NTB) each at 5.0 mg kg −1 body weight were ABSO and albendazole sulfone (ABSO 2 ). The areas under the plasma concentration-time curve (AUC) for ABSO and ABSO 2 were significantly (P 2 metabolites were larger following administration of ABZ than NTB in 1-month- but not 8-month-old sheep and the AUC of the ABSO and ABSO 2 metabolites were greater following ABSO than ABZ as parent compound in 8-month-old sheep only. The larger AUC values for metabolites following administration of ABSO as the parent compound were generally coincident with significantly higher maximum (C max ) concentrations and not with persistence in the body, since mean residence times (MRT) of the metabolites were not significantly different from those determined following ABZ and NTB as parent compounds. The lower metabolite concentration following administration of NTB may have been a feature of its requirement for metabolic conversion and its larger molecular weight. Correction of AUC values for molecular weight removed any significant differences between AUC values for either metabolite in 8-month-old lambs. The corrected metabolite AUCs following NTB were, however, significantly lower than those following ABSO adminstration in 1-month-old lambs, suggesting that immature metabolic processes in these animals contributed to the lower relative bioavailability of NTB in this age group. Age did not affect the disposition of metabolites following ABZ or ABSO but the AUC of the ABSO metabolite following NTB was significantly ( P = 0.014) lower in 1-month- than in 8-month-old sheep.
Laura Rinaldi - One of the best experts on this subject based on the ideXlab platform.
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The maintenance of anthelmintic efficacy in sheep in a Mediterranean climate.
Veterinary Parasitology, 2014Co-Authors: Laura Rinaldi, Eric R. Morgan, Antonio Bosco, Gerald C. Coles, Giuseppe CringoliAbstract:To determine how far management practices on small ruminant dairy flocks in southern Italy have influenced the development of anthelmintic resistance (AR), faecal egg count (FEC) reduction tests were run on 54 sheep farms using the FLOTAC technique with a sensitivity of 2 eggs per gram of faeces. Tests were run on groups of sheep (12–20 animals per group) using six anthelmintics administered orally: levamisole on 8 farms, ivermectin (half and full dose) on 8 farms, moxidectin on 3 farms, monepantel on 8 farms, Netobimin on 22 farms (pooled samples) and albendazole on 5 farms (pooled samples). Different formulae and statistics were used to calculate FEC reductions and confidence intervals based on the presence of a control group and/or the use of pooled samples. A very high average efficacy was obtained with all anthelmintics tested as follows: levamisole 99.3% (range across farms 98–100%), ivermectin half dose 99.5% (98.0–100%), ivermectin full dose 99.9% (99.3–100%), moxidectin 100% (99.9–100%), monepantel 99.4% (97–100%), Netobimin 99.1% (92–100%) and albendazole 100%. The results suggest that the development of AR in small ruminants could be limited in countries with a Mediterranean type of climate provided that refugia of the nematode populations are maintained, anthelmintic use is restricted and movement of animals is not permitted to spread resistance.
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effects of strategic anthelmintic treatments on the milk production of dairy sheep naturally infected by gastrointestinal strongyles
Veterinary Parasitology, 2008Co-Authors: Giuseppe Cringoli, F. Jackson, Vincenzo Veneziano, Jozef Vercruysse, A W Greer, V Fedele, Laura Mezzino, Laura RinaldiAbstract:The present paper was aimed at assessing the benefit of strategic anthelmintic treatments on milk production in four commercial dairy sheep farms in Southern Italy whose animals were naturally infected by gastrointestinal (GI) strongyles and Dicrocoelium dendriticum. The scheme was based on two treatments timed in relationship to parturition, i.e. the first with moxidectin in the periparturient period and the second with Netobimin at the mid/end of lactation. On each farm, two similar groups (20 animals each) were formed, one untreated control group and one group treated according to the above-mentioned scheme. Faecal egg counts (FEC) were performed on each study animal at the start of the trial and then monthly until the end of the study; in addition, milk production was recorded for each animal fortnightly in each farm for the lactation period. The results showed a significant increase in milk yield across all four farms that ranged from 19% to 44% improvement in milk yield. The benefit in milk yield in addition to considerably reduced egg output of the treated animals provide clear evidence that the two main aims of prophylactic parasite control, i.e. to maintain or improve animal performance and to reduce pasture contamination, can be achieved using strategic anthelmintic treatments.
Capece, Bettencourt Preto Sebastião - One of the best experts on this subject based on the ideXlab platform.
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Caracterización farmacológica del albendazol sulfóxido y de sus enantiómeros en ovejas y ratas : análisis del metabolismo ruminal /
Bellaterra : Universitat Autònoma de Barcelona. Facultat de Veterinària, 2002Co-Authors: Capece, Bettencourt Preto SebastiãoAbstract:El objetivo principal del trabajo presentado fue analizar el comportamiento farmacologico de un antihelmíntico de la familia de los benzimidazoles, el albendazol sulfóxido (ABZSO) y de sus enantiómeros, evaluando su capacidad para atravesar la barrera placentária y causar embriotoxicidad y malformaciones congénitas. Para ello se estudió la cinética metabólica en fluido ruminal, utilizando un modelo de fermentadores de doble flujo, y la cinética plasmática en ovejas. Posteriormente se analizó el paso placentario de los enantiómeros de ABZSO en ovejas y las concentraciones embrionarias en ratas. Las muestras colectadas en estos procesos se analizaron mediante una técnica de HPLC (High Performance Liquid Chromatography) para cuantificar la presencia de Netobimin (NTB), albendazol (ABZ), ABZSO y sus enantiómeros y el metabolito albendazol sulfona (ABZSO2). El estudio de las malformaciones externas se llevó a cabo por observación directa, mientras que las malformaciones esqueléticas se analizaron mediante tinción con rojo de alizarina S y posterior transparentación de los tejidos blandos. En los fluidos ruminales se observó un predominio de los procesos de reducción de NTB a ABZ y de ABZSO a ABZ en comparación con los procesos de oxidación de ABZ a ABZSO y de éste a ABZSO2. Por otra parte, no fueron observados procesos enantioselectivos en el metabolismo de los enantiómeros de ABZSO. En el plasma de las ovejas se observó un predominio del (+)-ABZSO, mientras que en la rata los dos enantiómeros presentaron un perfil cinético semejante, sugiriendo la existencia de diferencias entre especies. En estos estudios no se observaron diferencias relacionadas con el sexo y la gestación en el perfil farmacocinético de los enantiómeros de ABZSO en ovejas. También se ha observado que los dos enantiómeros tienen capacidad de atravesar la barrera placentaria de las ratas y de las ovejas en elevadas concentraciones y que la placenta de la oveja impedía en cierto grado el paso de estas moléculas hacia el feto. Asimismo se observó un elevado poder embriotóxico y alta capacidad teratógena del ABZSO cuando se administró la forma racémica. Cuando se administraron los enantiómeros por separado se pudo observar que los dos son buenos substratos de la sulfonación y que siguen un perfil cinético similar. Asimismo no se ha observado una reracemización, indicando este hecho una gran estabilidad de los enantiómeros de ABZSO y una baja capacidad reductora en los fluidos gastrointestinales de la rata.The main objective of this work was to analyse the pharmacological behaviour of a benzimidazole anthelmintic compound, albendazole sulphoxide (ABZSO) and its enantiomers, evaluating their ability to pass through the placental barrier and to produce developmental toxicity. The ruminal fluid kinetics of these compounds in artificial rumens, and the plasma kinetics in sheep was performed. The placental transfer and the embryo concentration of the ABZSO enantiomers were also studied in sheep and rats respectively. All the collected samples were analysed by HPLC (High Performance Liquid Chromatography) in order to determine Netobimin (NTB), albendazole (ABZ), albendazole sulfoxide (ABZSO) and its enantiomers, and the metabolite sulfone (ABZSO2) concentration. The study of external abnormalities was performed by direct observation, whereas the skeletal malformation analysis was done using red alizarin S before transparentation of the smooth tissue. The reductive reations of the ruminal flora from NTB to ABZ and from ABZSO to ABZ were higher than the oxidation from ABZ to ABZSO and from ABZSO to ABZSO2. In other hand, no differences concerning the production or consumption of ABZSO enantiomers by the ruminal flora were observed, indicating that the ruminal bacteria metabolism was not enantioselective. In the sheep plasma there was a predominance of (+)-ABZSO, whereas in the rat plasma, both enantiomers showed similar kinetics profile, suggesting the existence of differences in ABZSO enantiomers plasma concentrations species. In our studies no pharmacokinetic differences of ABZSO enantiomers related to sex and pregnancy were observed in sheep. Both ABZSO enantiomers show the ability to pass through the placental barrier of rats and sheep, and that the sheep placenta impaired these compounds to reach the foetus. The ABZSO caused embrionary and teratogenic effects when administered in racemic form indicating that these effects were due to the presence of both enantiomers. When the enantiomers were administered separately, both enantiomers showed to be good substrates of sulfonation, and also to have a similar kinetic profile. Also, no reracemisation was observed after both enantiomers administration, indicating the high stability of ABZSO enantiomers, and the low reductive capacity of rat gastrointestinal fluid
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Caracterización farmacológica del albendazol sulfóxido y de sus enantiómeros en ovejas y ratas. Análisis del metabolismo ruminal
'Universitat Autonoma de Barcelona', 2001Co-Authors: Capece, Bettencourt Preto SebastiãoAbstract:El objetivo principal del trabajo presentado fue analizar el comportamiento farmacologico de un antihelmíntico de la familia de los benzimidazoles, el albendazol sulfóxido (ABZSO) y de sus enantiómeros, evaluando su capacidad para atravesar la barrera placentária y causar embriotoxicidad y malformaciones congénitas. Para ello se estudió la cinética metabólica en fluido ruminal, utilizando un modelo de fermentadores de doble flujo, y la cinética plasmática en ovejas. Posteriormente se analizó el paso placentario de los enantiómeros de ABZSO en ovejas y las concentraciones embrionarias en ratas. Las muestras colectadas en estos procesos se analizaron mediante una técnica de HPLC (High Performance Liquid Chromatography) para cuantificar la presencia de Netobimin (NTB), albendazol (ABZ), ABZSO y sus enantiómeros y el metabolito albendazol sulfona (ABZSO2). El estudio de las malformaciones externas se llevó a cabo por observación directa, mientras que las malformaciones esqueléticas se analizaron mediante tinción con rojo de alizarina S y posterior transparentación de los tejidos blandos. En los fluidos ruminales se observó un predominio de los procesos de reducción de NTB a ABZ y de ABZSO a ABZ en comparación con los procesos de oxidación de ABZ a ABZSO y de éste a ABZSO2. Por otra parte, no fueron observados procesos enantioselectivos en el metabolismo de los enantiómeros de ABZSO. En el plasma de las ovejas se observó un predominio del (+)-ABZSO, mientras que en la rata los dos enantiómeros presentaron un perfil cinético semejante, sugiriendo la existencia de diferencias entre especies. En estos estudios no se observaron diferencias relacionadas con el sexo y la gestación en el perfil farmacocinético de los enantiómeros de ABZSO en ovejas. También se ha observado que los dos enantiómeros tienen capacidad de atravesar la barrera placentaria de las ratas y de las ovejas en elevadas concentraciones y que la placenta de la oveja impedía en cierto grado el paso de estas moléculas hacia el feto. Asimismo se observó un elevado poder embriotóxico y alta capacidad teratógena del ABZSO cuando se administró la forma racémica. Cuando se administraron los enantiómeros por separado se pudo observar que los dos son buenos substratos de la sulfonación y que siguen un perfil cinético similar. Asimismo no se ha observado una reracemización, indicando este hecho una gran estabilidad de los enantiómeros de ABZSO y una baja capacidad reductora en los fluidos gastrointestinales de la rata.The main objective of this work was to analyse the pharmacological behaviour of a benzimidazole anthelmintic compound, albendazole sulphoxide (ABZSO) and its enantiomers, evaluating their ability to pass through the placental barrier and to produce developmental toxicity. The ruminal fluid kinetics of these compounds in artificial rumens, and the plasma kinetics in sheep was performed. The placental transfer and the embryo concentration of the ABZSO enantiomers were also studied in sheep and rats respectively. All the collected samples were analysed by HPLC (High Performance Liquid Chromatography) in order to determine Netobimin (NTB), albendazole (ABZ), albendazole sulfoxide (ABZSO) and its enantiomers, and the metabolite sulfone (ABZSO2) concentration. The study of external abnormalities was performed by direct observation, whereas the skeletal malformation analysis was done using red alizarin S before transparentation of the smooth tissue. The reductive reations of the ruminal flora from NTB to ABZ and from ABZSO to ABZ were higher than the oxidation from ABZ to ABZSO and from ABZSO to ABZSO2. In other hand, no differences concerning the production or consumption of ABZSO enantiomers by the ruminal flora were observed, indicating that the ruminal bacteria metabolism was not enantioselective. In the sheep plasma there was a predominance of (+)-ABZSO, whereas in the rat plasma, both enantiomers showed similar kinetics profile, suggesting the existence of differences in ABZSO enantiomers plasma concentrations species. In our studies no pharmacokinetic differences of ABZSO enantiomers related to sex and pregnancy were observed in sheep. Both ABZSO enantiomers show the ability to pass through the placental barrier of rats and sheep, and that the sheep placenta impaired these compounds to reach the foetus. The ABZSO caused embrionary and teratogenic effects when administered in racemic form indicating that these effects were due to the presence of both enantiomers. When the enantiomers were administered separately, both enantiomers showed to be good substrates of sulfonation, and also to have a similar kinetic profile. Also, no reracemisation was observed after both enantiomers administration, indicating the high stability of ABZSO enantiomers, and the low reductive capacity of rat gastrointestinal fluid
Giuseppe Cringoli - One of the best experts on this subject based on the ideXlab platform.
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The maintenance of anthelmintic efficacy in sheep in a Mediterranean climate.
Veterinary Parasitology, 2014Co-Authors: Laura Rinaldi, Eric R. Morgan, Antonio Bosco, Gerald C. Coles, Giuseppe CringoliAbstract:To determine how far management practices on small ruminant dairy flocks in southern Italy have influenced the development of anthelmintic resistance (AR), faecal egg count (FEC) reduction tests were run on 54 sheep farms using the FLOTAC technique with a sensitivity of 2 eggs per gram of faeces. Tests were run on groups of sheep (12–20 animals per group) using six anthelmintics administered orally: levamisole on 8 farms, ivermectin (half and full dose) on 8 farms, moxidectin on 3 farms, monepantel on 8 farms, Netobimin on 22 farms (pooled samples) and albendazole on 5 farms (pooled samples). Different formulae and statistics were used to calculate FEC reductions and confidence intervals based on the presence of a control group and/or the use of pooled samples. A very high average efficacy was obtained with all anthelmintics tested as follows: levamisole 99.3% (range across farms 98–100%), ivermectin half dose 99.5% (98.0–100%), ivermectin full dose 99.9% (99.3–100%), moxidectin 100% (99.9–100%), monepantel 99.4% (97–100%), Netobimin 99.1% (92–100%) and albendazole 100%. The results suggest that the development of AR in small ruminants could be limited in countries with a Mediterranean type of climate provided that refugia of the nematode populations are maintained, anthelmintic use is restricted and movement of animals is not permitted to spread resistance.
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effects of strategic anthelmintic treatments on the milk production of dairy sheep naturally infected by gastrointestinal strongyles
Veterinary Parasitology, 2008Co-Authors: Giuseppe Cringoli, F. Jackson, Vincenzo Veneziano, Jozef Vercruysse, A W Greer, V Fedele, Laura Mezzino, Laura RinaldiAbstract:The present paper was aimed at assessing the benefit of strategic anthelmintic treatments on milk production in four commercial dairy sheep farms in Southern Italy whose animals were naturally infected by gastrointestinal (GI) strongyles and Dicrocoelium dendriticum. The scheme was based on two treatments timed in relationship to parturition, i.e. the first with moxidectin in the periparturient period and the second with Netobimin at the mid/end of lactation. On each farm, two similar groups (20 animals each) were formed, one untreated control group and one group treated according to the above-mentioned scheme. Faecal egg counts (FEC) were performed on each study animal at the start of the trial and then monthly until the end of the study; in addition, milk production was recorded for each animal fortnightly in each farm for the lactation period. The results showed a significant increase in milk yield across all four farms that ranged from 19% to 44% improvement in milk yield. The benefit in milk yield in addition to considerably reduced egg output of the treated animals provide clear evidence that the two main aims of prophylactic parasite control, i.e. to maintain or improve animal performance and to reduce pasture contamination, can be achieved using strategic anthelmintic treatments.
C Cristofol - One of the best experts on this subject based on the ideXlab platform.
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effect of ruminal microflora on the biotransformation of Netobimin albendazole albendazole sulfoxide and albendazole sulfoxide enantiomers in an artificial rumen
Journal of Animal Science, 2001Co-Authors: Bettencourt P S Capece, G Castells, Margarita Arboix, Sergio Calsamiglia, C CristofolAbstract:: The effect of ruminal flora on the disposition of benzimidazole anthelmintic drugs was studied in dual-flow continuous-culture fermenters (artificial rumens). Six 1,320-mL artificial rumens were inoculated with ruminal fluid and fermentation conditions were maintained constant at 39 degrees C, pH 6.4, solid dilution rate of 5%/h, and liquid dilution rate of 10%/h to simulate standard ruminal fermentation conditions. The study was repeated in two consecutive periods. Two hours after the inoculation of rumen fluid, the fermenters were fed 30 g of a 60:40 forage:concentrate ration. Within each period two fermenters per treatment were immediately dosed with 104 mg of Netobimin, 52 mg of albendazole, or 39 mg of albendazole sulfoxide. Concentrations of Netobimin, albendazole, albendazole sulfoxide and its enantiomers, and albendazole sulfone were analyzed by high performance liquid chromatography at 0.25, 0.5, 1, 2, 4, 6, and 8 h after dosage. Reductive metabolism by the ruminal bacteria was observed, favoring the production of albendazole, the most potent anthelmintic molecule. No differences in the production or consumption of albendazole sulfoxide enantiomers were observed, indicating that the ruminal bacteria metabolism was not enantioselective. Because benzimidazole anthelmintic drugs are generally administered orally, the ruminal flora play an important role in the bioavailability of these drugs. In our study, increased concentrations of albendazole in the three treatments, due to reductive ruminal biotransformation, suggests that ruminal biotransformation may improve the efficacy of orally administered Netobimin, albendazole, and albendazole sulfoxide.