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Martin L. Cross - One of the best experts on this subject based on the ideXlab platform.
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mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums trichosurus vulpecula following low dose subcutaneous injection of mycobacterium bovis
Preventive Veterinary Medicine, 2013Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with <50 CFU of M. bovis, then fitted with mortality signal emitting radio tracking collars, released and re-tracked for 6 months. Possum survival probability was 89% up to 12 weeks post-injection (p.i.), but cumulative mortality was rapid from then on. The median survival period, based on study of 38 possums, was 18 weeks p.i.; this corresponds with a predicted time interval of 11 weeks between first presentation of TB as palpable lymphadenomegaly and death for an average possum, shorter than period values currently used in possum TB epidemiological modelling. We also examined Gross Pathology in 11 possums by post mortem necropsy, and confirmed lymphadenomegaly and tuberculous lesions at 7 and 12 weeks p.i. Extra-peripheral Gross lesions were more frequent among possums at 12 weeks p.i. than at 7 weeks, while the occurrence of lung lesions (the most likely cause of disease-induced mortality) was apparent in animals at 12 weeks but not at 7 weeks p.i. Our results suggest that the time course of TB from development of Gross lesions to mortality may be shorter than previously estimated from field studies of naturally tuberculous possums.
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Mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums (Trichosurus vulpecula) following low dose subcutaneous injection of Mycobacterium bovis.
Preventive Veterinary Medicine, 2012Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with
Graham Nugent - One of the best experts on this subject based on the ideXlab platform.
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mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums trichosurus vulpecula following low dose subcutaneous injection of mycobacterium bovis
Preventive Veterinary Medicine, 2013Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with <50 CFU of M. bovis, then fitted with mortality signal emitting radio tracking collars, released and re-tracked for 6 months. Possum survival probability was 89% up to 12 weeks post-injection (p.i.), but cumulative mortality was rapid from then on. The median survival period, based on study of 38 possums, was 18 weeks p.i.; this corresponds with a predicted time interval of 11 weeks between first presentation of TB as palpable lymphadenomegaly and death for an average possum, shorter than period values currently used in possum TB epidemiological modelling. We also examined Gross Pathology in 11 possums by post mortem necropsy, and confirmed lymphadenomegaly and tuberculous lesions at 7 and 12 weeks p.i. Extra-peripheral Gross lesions were more frequent among possums at 12 weeks p.i. than at 7 weeks, while the occurrence of lung lesions (the most likely cause of disease-induced mortality) was apparent in animals at 12 weeks but not at 7 weeks p.i. Our results suggest that the time course of TB from development of Gross lesions to mortality may be shorter than previously estimated from field studies of naturally tuberculous possums.
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Mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums (Trichosurus vulpecula) following low dose subcutaneous injection of Mycobacterium bovis.
Preventive Veterinary Medicine, 2012Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with
Jackie Whitford - One of the best experts on this subject based on the ideXlab platform.
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mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums trichosurus vulpecula following low dose subcutaneous injection of mycobacterium bovis
Preventive Veterinary Medicine, 2013Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with <50 CFU of M. bovis, then fitted with mortality signal emitting radio tracking collars, released and re-tracked for 6 months. Possum survival probability was 89% up to 12 weeks post-injection (p.i.), but cumulative mortality was rapid from then on. The median survival period, based on study of 38 possums, was 18 weeks p.i.; this corresponds with a predicted time interval of 11 weeks between first presentation of TB as palpable lymphadenomegaly and death for an average possum, shorter than period values currently used in possum TB epidemiological modelling. We also examined Gross Pathology in 11 possums by post mortem necropsy, and confirmed lymphadenomegaly and tuberculous lesions at 7 and 12 weeks p.i. Extra-peripheral Gross lesions were more frequent among possums at 12 weeks p.i. than at 7 weeks, while the occurrence of lung lesions (the most likely cause of disease-induced mortality) was apparent in animals at 12 weeks but not at 7 weeks p.i. Our results suggest that the time course of TB from development of Gross lesions to mortality may be shorter than previously estimated from field studies of naturally tuberculous possums.
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Mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums (Trichosurus vulpecula) following low dose subcutaneous injection of Mycobacterium bovis.
Preventive Veterinary Medicine, 2012Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with
Ivor Yockney - One of the best experts on this subject based on the ideXlab platform.
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mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums trichosurus vulpecula following low dose subcutaneous injection of mycobacterium bovis
Preventive Veterinary Medicine, 2013Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with <50 CFU of M. bovis, then fitted with mortality signal emitting radio tracking collars, released and re-tracked for 6 months. Possum survival probability was 89% up to 12 weeks post-injection (p.i.), but cumulative mortality was rapid from then on. The median survival period, based on study of 38 possums, was 18 weeks p.i.; this corresponds with a predicted time interval of 11 weeks between first presentation of TB as palpable lymphadenomegaly and death for an average possum, shorter than period values currently used in possum TB epidemiological modelling. We also examined Gross Pathology in 11 possums by post mortem necropsy, and confirmed lymphadenomegaly and tuberculous lesions at 7 and 12 weeks p.i. Extra-peripheral Gross lesions were more frequent among possums at 12 weeks p.i. than at 7 weeks, while the occurrence of lung lesions (the most likely cause of disease-induced mortality) was apparent in animals at 12 weeks but not at 7 weeks p.i. Our results suggest that the time course of TB from development of Gross lesions to mortality may be shorter than previously estimated from field studies of naturally tuberculous possums.
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Mortality rate and Gross Pathology due to tuberculosis in wild brushtail possums (Trichosurus vulpecula) following low dose subcutaneous injection of Mycobacterium bovis.
Preventive Veterinary Medicine, 2012Co-Authors: Graham Nugent, Ivor Yockney, Jackie Whitford, Martin L. CrossAbstract:Gross Pathology due to tuberculosis can be established experimentally in brushtail possums (Trichosurus vulpecula) within 7 weeks of injection of virulent Mycobacterium bovis into subcutaneous connective tissues of the peripheral limbs. This Pathology involves lymphadenomegaly and development of Gross lesions in peripheral lymph nodes, with subsequent Gross lesions in the lungs and reticuloendothelial organs. Using this artificial infection model, we here assessed the mortality rate for possums in the wild, to provide new information on the likely survival period for New Zealand's major wildlife host. Possums were trapped and inoculated with
Aravindan Kolandaivelu - One of the best experts on this subject based on the ideXlab platform.
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acute enhancement of necrotic radio frequency ablation lesions in left atrium and pulmonary vein ostia in swine model with non contrast enhanced t1 weighted mri
Magnetic Resonance in Medicine, 2020Co-Authors: Michael A Guttman, Sarah Fink, Rick Tunin, Ehud J Schmidt, Daniel A Herzka, Henry R Halperin, Aravindan KolandaiveluAbstract:PURPOSE To evaluate non-contrast-enhanced MRI of acute radio-frequency ablation (RFA) lesions in the left atrium (LA) and pulmonary vein (PV) ostia. The goal is to provide a method for discrimination between necrotic (permanent) lesions and reversible injury, which is associated with recurrence after treatment of atrial fibrillation. METHODS Fifteen normal swine underwent RFA around the right-superior PV ostia. Electrical pulmonary vein isolation (PVI) was verified by electro-anatomic mapping (EAM) and pacing. MRI was carried out using a 3D respiratory-gated T1 -weighted long inversion time (TWILITE) sequence without contrast agent. Key settings were: inversion time 700 ms, triggering over 2 cardiac cycles, pixel size 1.1 mm3 . Contrast-enhanced imaging and T2 -weighted imaging were carried out for comparison. Six animals were sacrificed on ablation day for TTC-stained Gross Pathology, 9 animals were sacrificed after 2-3 mo after repeat EAM and MRI. Image intensity ratio (IIR) was used to measure lesion enhancement, and Gross Pathology was used to validate image enhancement patterns and compare lesion widths. RESULTS RFA lesions exhibited unambiguous enhancement in acute TWILITE imaging (IIR = 2.34 ± 0.49 at 1.5T), and the enhancement patterns corresponded well with Gross Pathology. Lesion widths in MRI correlated well with Gross Pathology (R2 = 0.84), with slight underestimation by 0.9 ± 0.5 mm. Lesion enhancement subsided chronically. CONCLUSION TWILITE imaging allowed acute detection of permanent RFA lesions in swine LA and PV ostia, without the need for contrast agent. Lesion enhancement pattern showed good correspondence to Gross Pathology and was well visualized by volume rendering. This method may provide valuable intra- or post-procedural assessment of RFA treatment.
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Acute enhancement of necrotic radio-frequency ablation lesions in left atrium and pulmonary vein ostia in swine model with non-contrast-enhanced T1 -weighted MRI.
Magnetic resonance in medicine, 2019Co-Authors: Michael A Guttman, Sarah Fink, Rick Tunin, Ehud J Schmidt, Daniel A Herzka, Henry R Halperin, Susumu Tao, Aravindan KolandaiveluAbstract:Purpose To evaluate non-contrast-enhanced MRI of acute radio-frequency ablation (RFA) lesions in the left atrium (LA) and pulmonary vein (PV) ostia. The goal is to provide a method for discrimination between necrotic (permanent) lesions and reversible injury, which is associated with recurrence after treatment of atrial fibrillation. Methods Fifteen normal swine underwent RFA around the right-superior PV ostia. Electrical pulmonary vein isolation (PVI) was verified by electro-anatomic mapping (EAM) and pacing. MRI was carried out using a 3D respiratory-gated T1 -weighted long inversion time (TWILITE) sequence without contrast agent. Key settings were: inversion time 700 ms, triggering over 2 cardiac cycles, pixel size 1.1 mm3 . Contrast-enhanced imaging and T2 -weighted imaging were carried out for comparison. Six animals were sacrificed on ablation day for TTC-stained Gross Pathology, 9 animals were sacrificed after 2-3 mo after repeat EAM and MRI. Image intensity ratio (IIR) was used to measure lesion enhancement, and Gross Pathology was used to validate image enhancement patterns and compare lesion widths. Results RFA lesions exhibited unambiguous enhancement in acute TWILITE imaging (IIR = 2.34 ± 0.49 at 1.5T), and the enhancement patterns corresponded well with Gross Pathology. Lesion widths in MRI correlated well with Gross Pathology (R2 = 0.84), with slight underestimation by 0.9 ± 0.5 mm. Lesion enhancement subsided chronically. Conclusion TWILITE imaging allowed acute detection of permanent RFA lesions in swine LA and PV ostia, without the need for contrast agent. Lesion enhancement pattern showed good correspondence to Gross Pathology and was well visualized by volume rendering. This method may provide valuable intra- or post-procedural assessment of RFA treatment.
