The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Maxwell J Scott - One of the best experts on this subject based on the ideXlab platform.
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Development and evaluation of male-only strains of the Australian sheep blowfly, Lucilia cuprina
BMC Genetics, 2014Co-Authors: Maxwell J ScottAbstract:The Australian sheep blowfly Lucilia cuprina (Wiedemann) is a major pest of sheep in Australia and New Zealand. From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program. The FFK strains carried eye color mutations that were lethal to females in the field but not under conditions in the mass rearing facility. Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome. Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing. A stable transgenic strain of L. cuprina that carried one or more dominant repressible female lethal genes offered the potential for efficient genetic control of blowfly populations. Here I review our research on tetracycline-repressible female lethal genetic systems, Lucilia germ-line transformation and sex determination genes that ultimately led to the successful development of transgenic "male-only" strains of L. cuprina . The technology developed for L. cuprina should be directly transferable to other blowfly livestock pests including L. sericata and the New World and Old World screwworm. 29
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transgenic sexing system for genetic control of the australian sheep blow fly lucilia cuprina
Insect Biochemistry and Molecular Biology, 2014Co-Authors: Fang Li, Holly A Wantuch, Rebecca J Linger, Esther J Belikoff, Maxwell J ScottAbstract:Abstract The New World screwworm and the Australian sheep blowfly Lucilia cuprina are devastating pests of livestock. The larvae of these species feed on the tissue of the living animal and can cause death if untreated. The sterile insect technique or SIT was used to eradicate screwworm from North and Central America. This inspired efforts to develop strains containing complex chromosomal rearrangements for genetic control of L. cuprina in Australia. Although one field trial was promising, the approach was abandoned due to costs and difficulties in mass rearing the strain. As the efficiency of SIT can be significantly increased if only sterile males are released, we have developed transgenic strains of L. cuprina that carry a dominant tetracycline repressible female lethal genetic system. Lethality is due to overexpression of an auto-regulated tetracycline repressible transactivator (tTA) gene and occurs mostly at the pupal stage. Dominant female lethality was achieved by replacing the Drosophila hsp70 core promoter with a Lucilia hsp70 core promoter-5′UTR for tTA overexpression. The strains carry a dominant strongly expressed marker that will facilitate identification in the field. Interestingly, the sexes could be reliably sorted by fluorescence or color from the early first instar larval stage as females that overexpress tTA also overexpress the linked marker gene. Male-only strains of L. cuprina developed in this study could form the basis for a future genetic control program. Moreover, the system developed for L. cuprina should be readily transferrable to other major calliphorid livestock pests including the New and Old World screwworm.
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progress towards the development of a transgenic strain of the australian sheep blowfly lucilia cuprina suitable for a male only sterile release program
Insect Biochemistry and Molecular Biology, 2004Co-Authors: Maxwell J Scott, Jorg C Heinrich, Xuelei LiAbstract:The Australian sheep blowfly Lucilia cuprina is the most important pest species involved in cutaneous myiasis (flystrike) of sheep in Australia and New Zealand. In New Zealand L. cuprina is primarily controlled through the application of insecticides. However, there is an increased interest in biological methods of control of this species. We have proposed to develop a genetically modified strain of L. cuprina that would be ideal for a male-only sterile release program. To that end we have developed a method for making transgenic L. cuprina using a piggyBac vector and an EGFP marker gene. We have also developed in Drosophila melanogaster a 2-component genetic system for controlling female viability. Females carrying both components of the system die unless fed a diet that contains tetracycline. We anticipate that the female-killing system will need to be optimised for L. cuprina in order to make a strain with the properties required for a male-only release program.
John W Schrader - One of the best experts on this subject based on the ideXlab platform.
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distinct structural features of caprin 1 mediate its interaction with g3bp 1 and its induction of phosphorylation of eukaryotic translation initiation factor 2alpha entry to cytoplasmic stress granules and selective interaction with a subset of mrnas
Molecular and Cellular Biology, 2007Co-Authors: Samuel Solomon, Yaoxian Xu, Bin Wang, Muriel D David, Peter Schubert, Derek Kennedy, John W SchraderAbstract:Caprin-1 is a ubiquitously expressed, well-conserved cytoplasmic phosphoprotein that is needed for normal progression through the G1-S phase of the cell cycle and occurs in postsynaptic granules in dendrites of neurons. We demonstrate that Caprin-1 colocalizes with RasGAP SH3 domain binding protein-1 (G3BP-1) in cytoplasmic RNA granules associated with microtubules and concentrated in the leading and trailing edge of migrating cells. Caprin-1 exhibits a highly conserved motif, F(M/I/L)Q(D/E)Sx(I/L)D that binds to the NTF2-like domain of G3BP-1. The carboxy-terminal region of Caprin-1 selectively bound mRNA for c-Myc or cyclin D2, this binding being diminished by mutation of the three RGG motifs and abolished by deletion of the RGG-rich region. Overexpression of Caprin-1 induced phosphorylation of eukaryotic translation initiation factor 2 (eIF-2) through a mechanism that depended on its ability to bind mRNA, resulting in global inhibition of protein synthesis. However, cells lacking Caprin-1 exhibited no changes in global rates of protein synthesis, suggesting that physiologically, the effects of Caprin-1 on translation were limited to restricted subsets of mRNAs. Overexpression of Caprin-1 induced the formation of cytoplasmic stress granules (SG). Its ability to bind RNA was required to induce SG formation but not necessarily its ability to enter SG. The ability of Caprin-1 or G3BP-1 to induce SG formation or enter them did not depend on their association with each other. The Caprin-1/G3BP-1 complex is likely to regulate the transport and translation of mRNAs of proteins involved with synaptic plasticity in neurons and cellular proliferation and migration in multiple cell types. Caprin-1 is a ubiquitously expressed, well-conserved cytoplasmic phosphoprotein (13). Its levels increase when resting cells enter the cell cycle and decrease when proliferation ceases and cells differentiate (13). In most tissues, levels of Caprin-1 correlate with the frequency of proliferating cells,
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distinct structural features of caprin 1 mediate its interaction with g3bp 1 and its induction of phosphorylation of eukaryotic translation initiation factor 2alpha entry to cytoplasmic stress granules and selective interaction with a subset of mrnas
Molecular and Cellular Biology, 2007Co-Authors: Samuel Solomon, Yaoxian Xu, Bin Wang, Muriel D David, Peter Schubert, Derek Kennedy, John W SchraderAbstract:Caprin-1 is a ubiquitously expressed, well-conserved cytoplasmic phosphoprotein that is needed for normal progression through the G(1)-S phase of the cell cycle and occurs in postsynaptic granules in dendrites of neurons. We demonstrate that Caprin-1 colocalizes with RasGAP SH3 domain binding protein-1 (G3BP-1) in cytoplasmic RNA granules associated with microtubules and concentrated in the leading and trailing edge of migrating cells. Caprin-1 exhibits a highly conserved motif, F(M/I/L)Q(D/E)Sx(I/L)D that binds to the NTF-2-like domain of G3BP-1. The carboxy-terminal region of Caprin-1 selectively bound mRNA for c-Myc or cyclin D2, this binding being diminished by mutation of the three RGG motifs and abolished by deletion of the RGG-rich region. Overexpression of Caprin-1 induced phosphorylation of eukaryotic translation initiation factor 2alpha (eIF-2alpha) through a mechanism that depended on its ability to bind mRNA, resulting in global inhibition of protein synthesis. However, cells lacking Caprin-1 exhibited no changes in global rates of protein synthesis, suggesting that physiologically, the effects of Caprin-1 on translation were limited to restricted subsets of mRNAs. Overexpression of Caprin-1 induced the formation of cytoplasmic stress granules (SG). Its ability to bind RNA was required to induce SG formation but not necessarily its ability to enter SG. The ability of Caprin-1 or G3BP-1 to induce SG formation or enter them did not depend on their association with each other. The Caprin-1/G3BP-1 complex is likely to regulate the transport and translation of mRNAs of proteins involved with synaptic plasticity in neurons and cellular proliferation and migration in multiple cell types.
Adela Mora-gutierrez - One of the best experts on this subject based on the ideXlab platform.
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Complexes of lutein with bovine and caprine caseins and their impact on lutein chemical stability in emulsion systems: Effect of arabinogalactan.
Journal of Dairy Science, 2018Co-Authors: Adela Mora-gutierrez, R Attaie, M T Núñez De González, S Woldesenbet, Y. Jung, S A MarquezAbstract:Lutein is an important xanthophyll carotenoid with many benefits to human health. Factors affecting the application of lutein as a functional ingredient in low-fat dairy-like beverages (pH 6.0–7.0) are not well understood. The interactions of bovine and caprine caseins with hydrophobic lutein were studied using UV/visible spectroscopy as well as fluorescence. Our studies confirmed that the aqueous solubility of lutein is improved after binding with bovine and caprine caseins. The rates of lutein solubilization by the binding to bovine and caprine caseins were as follows: caprine αS1-II-casein 34%, caprine αS1-I-casein 10%, and bovine casein 7% at 100 μM lutein. Fluorescence of the protein was quenched on binding supporting complex formation. The fluorescence experiments showed that the binding involves tryptophan residues and some nonspecific interactions. Scatchard plots of lutein binding to the caseins demonstrated competitive binding between the caseins and their sites of interaction with lutein. Competition experiments suggest that caprine αS1-II casein will bind a larger number of lutein molecules with higher affinity than other caseins. The chemical stability of lutein was largely dependent on casein type and significant increases occurred in the chemical stability of lutein with the following pattern: caprine αS1-II-casein > caprine αS1-I-casein > bovine casein. Addition of arabinogalactan to lutein-enriched emulsions increases the chemical stability of lutein-casein complexes during storage under accelerated photo-oxidation conditions at 25°C. Therefore, caprine αS1-II-casein alone and in combination with arabinogalactan can have important applications in the beverage industry as carrier of this xanthophyll carotenoid (lutein).
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Modeling Calcium-induced Solubility in Caprine Milk Caseins Using a Thermodynamic Linkage Approach
Journal of Dairy Science, 2010Co-Authors: Adela Mora-gutierrez, J.j. Basch, Harold M. Farrell, Thomas F. KumosinskiAbstract:The phenomena of calcium-induced precipitation of bovine and caprine whole caseins (salting out) and the resolubilization of these proteins at higher calcium concentrations (salting in) are thermodynamically linked with changes in protein solubility resulting from calcium binding. The differences in calcium sensitivities of caprine whole caseins under various conditions of temperature and ionic strength (KCl) appear to be correlated with the content of the α s1 -casein component. However, the solubility behavior of caprine whole caseins characterized by low content of α s1 -casein (5% of total) is more closely related to solubility properties displayed by bovine casein (38% of total). The properties of whole caprine casein high in or, α s1 -casein content (17% of total) appear to be dominated by the binding of calcium to higher affinity sites (phosphate groups), which results in less stability. Decreasing the temperature to 1°C dramatically altered the salting out of both caprine caseins but not bovine casein. These results suggested that the solubility and calcium-binding properties of caprine whole caseins are in part determined by hydrophobic interactions. However, salting out of both of the caprine caseins is effected by competitive K + -Ca 2+ binding at 1°C, indicating a role for ionic interactions as well. Because such KCl-dependent changes do not occur in whole bovine caseins, protein-protein interactions appear to be stronger in this case. These results show that alteration in casein composition can clearly effect the functionality of the whole casein and that thermodynamic linkage analysis can readily quantitate these differences that are linked to calcium binding. © 1993, American Dairy Science Association. All rights reserved.
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Hydration of Native and Rennin-Treated, Cold-Solubilized Caprine Caseins as Determined by Oxygen-17 Nuclear Magnetic Resonance
Journal of Dairy Science, 2001Co-Authors: Adela Mora-gutierrez, Harold M. FarrelAbstract:Abstract The hydration of native and rennin-coagulated bovine and caprine caseins was investigated by oxygen-17 nuclear magnetic resonance (NMR) and fitted by nonlinear regression analysis. A charge-charge interaction model (B 0 ) was employed to analyze the transverse relaxation (1/T 2 ) data. Relaxation differences between reconstituted native micelles at 10°C and rennin-coagulated, cold-solubilized micelles of caseins strongly suggest that important structural dissimilarities exist between these milk proteins that are due to differences in the ratios of α s1 - to β-CN. Variants of α s1 -CN had significant effects on caprine casein hydration. The differences were more pronounced in rennin-coagulated than in native casein micelles. All rennin-coagulated, cold-solubilized casein micelles demonstrated significant decreases in hydration. Micelles containing low α s1 -CN retain an open, highly hydrated structure, in comparison with similarly treated bovine and caprine casein micelles containing high α s1 -CN. Second virial coefficients (B 0 values) derived from oxygen-17 NMR data suggest that reconstituted bovine and caprine casein micelles containing high α s1 -CN exhibit strong interactions, which at first decrease then increase during clotting. In contrast, the native caprine casein micelles containing low α s1 -CN exhibit strong charge repulsions, which increase with clotting. The compositional differences are reflected in differences in the extent of protein-protein aggregation during casein clotting by rennin. Our results demonstrate that alteration in casein composition can dramatically alter cheese-making properties.
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Oxygen-17 Nuclear Magnetic Resonance Studies of Bovine and Caprine Casein Hydration and Activity in Deuterated Sugar Solutions
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Adela Mora-gutierrez, Thomas F. Kumosinski, Harold M. FarrellAbstract:The hydration of bovine and genetically variable caprine caseins in D2O solutions of sucrose and lactose was investigated by oxygen-17 NMR and fitted by nonlinear regression analysis. A charge−charge interaction model was employed to analyze the transverse relaxation (1/T2) data. Lactose caused increased hydration of the bovine casein and the caprine casein naturally low in αs1-casein, whereas sucrose led to increased hydration of the caprine casein naturally high in αs1-casein. At pD 7.20 and 21 °C the effect of charge−charge repulsive interactions on the native caseins generally leads to decreased protein stability in bovine and caprine caseins. However, addition of sugars causes stronger (attractive) interactions yielding more stable casein complexes with increased hydration. The calculated preferential binding term −(∂gs/∂gp) for casein mixtures suggests that sucrose and lactose are “preferentially” excluded from these milk proteins, yielding greater access to much of the aqueous compartment. This is ...
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Comparison of Hydration Behavior of Bovine and Caprine Caseins As Determined by Oxygen-17 Nuclear Magnetic Resonance: Temperature Dependence of Colloidal Stability
Journal of Agricultural and Food Chemistry, 1996Co-Authors: Adela Mora-gutierrez, Harold M. Farrell, Thomas F. KumosinskiAbstract:Oxygen-17 nuclear magnetic resonance (NMR) transverse relaxation rates for bovine and caprine casein micelles at various temperatures were analyzed by nonlinear regression analysis and a protein activity model. The dependence of the NMR transverse relaxation rates was markedly nonlinear due to interactions between protein molecules. Temperature dependences of the hydration parameters of the bovine and caprine casein micelles were in accordance with the hypothesis that hydrophobic interactions are the predominant forces responsible for the self-association of the caseins. Relaxation differences between reconstituted micelles of bovine and caprine caseins strongly suggest that important structural dissimilarities exist between these milk proteins that are due to differences in the ratios of αs1- to β-casein. A higher degree of hydration, characteristic of a more open and looser structure, is observed for caprine casein micelles high in αs1-casein at 21 and 37 °C. The observed hydration behavior of bovine ca...
Thomas F. Kumosinski - One of the best experts on this subject based on the ideXlab platform.
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Modeling Calcium-induced Solubility in Caprine Milk Caseins Using a Thermodynamic Linkage Approach
Journal of Dairy Science, 2010Co-Authors: Adela Mora-gutierrez, J.j. Basch, Harold M. Farrell, Thomas F. KumosinskiAbstract:The phenomena of calcium-induced precipitation of bovine and caprine whole caseins (salting out) and the resolubilization of these proteins at higher calcium concentrations (salting in) are thermodynamically linked with changes in protein solubility resulting from calcium binding. The differences in calcium sensitivities of caprine whole caseins under various conditions of temperature and ionic strength (KCl) appear to be correlated with the content of the α s1 -casein component. However, the solubility behavior of caprine whole caseins characterized by low content of α s1 -casein (5% of total) is more closely related to solubility properties displayed by bovine casein (38% of total). The properties of whole caprine casein high in or, α s1 -casein content (17% of total) appear to be dominated by the binding of calcium to higher affinity sites (phosphate groups), which results in less stability. Decreasing the temperature to 1°C dramatically altered the salting out of both caprine caseins but not bovine casein. These results suggested that the solubility and calcium-binding properties of caprine whole caseins are in part determined by hydrophobic interactions. However, salting out of both of the caprine caseins is effected by competitive K + -Ca 2+ binding at 1°C, indicating a role for ionic interactions as well. Because such KCl-dependent changes do not occur in whole bovine caseins, protein-protein interactions appear to be stronger in this case. These results show that alteration in casein composition can clearly effect the functionality of the whole casein and that thermodynamic linkage analysis can readily quantitate these differences that are linked to calcium binding. © 1993, American Dairy Science Association. All rights reserved.
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Oxygen-17 Nuclear Magnetic Resonance Studies of Bovine and Caprine Casein Hydration and Activity in Deuterated Sugar Solutions
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Adela Mora-gutierrez, Thomas F. Kumosinski, Harold M. FarrellAbstract:The hydration of bovine and genetically variable caprine caseins in D2O solutions of sucrose and lactose was investigated by oxygen-17 NMR and fitted by nonlinear regression analysis. A charge−charge interaction model was employed to analyze the transverse relaxation (1/T2) data. Lactose caused increased hydration of the bovine casein and the caprine casein naturally low in αs1-casein, whereas sucrose led to increased hydration of the caprine casein naturally high in αs1-casein. At pD 7.20 and 21 °C the effect of charge−charge repulsive interactions on the native caseins generally leads to decreased protein stability in bovine and caprine caseins. However, addition of sugars causes stronger (attractive) interactions yielding more stable casein complexes with increased hydration. The calculated preferential binding term −(∂gs/∂gp) for casein mixtures suggests that sucrose and lactose are “preferentially” excluded from these milk proteins, yielding greater access to much of the aqueous compartment. This is ...
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Comparison of Hydration Behavior of Bovine and Caprine Caseins As Determined by Oxygen-17 Nuclear Magnetic Resonance: Temperature Dependence of Colloidal Stability
Journal of Agricultural and Food Chemistry, 1996Co-Authors: Adela Mora-gutierrez, Harold M. Farrell, Thomas F. KumosinskiAbstract:Oxygen-17 nuclear magnetic resonance (NMR) transverse relaxation rates for bovine and caprine casein micelles at various temperatures were analyzed by nonlinear regression analysis and a protein activity model. The dependence of the NMR transverse relaxation rates was markedly nonlinear due to interactions between protein molecules. Temperature dependences of the hydration parameters of the bovine and caprine casein micelles were in accordance with the hypothesis that hydrophobic interactions are the predominant forces responsible for the self-association of the caseins. Relaxation differences between reconstituted micelles of bovine and caprine caseins strongly suggest that important structural dissimilarities exist between these milk proteins that are due to differences in the ratios of αs1- to β-casein. A higher degree of hydration, characteristic of a more open and looser structure, is observed for caprine casein micelles high in αs1-casein at 21 and 37 °C. The observed hydration behavior of bovine ca...
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Comparison of Hydration Behavior of Bovine and Caprine Caseins As Determined by Oxygen-17 Nuclear Magnetic Resonance: Effects of Salt
Journal of Agricultural and Food Chemistry, 1995Co-Authors: Adela Mora-gutierrez, Harold M. Farrell, Thomas F. KumosinskiAbstract:Oxygen-17 nuclear magnetic resonance (NMR) transverse relaxation measurements at 4.7 T were used to study the hydration properties of bovine and caprine casein solutions with and without NaCl. Measurements were carried out at 21 °C and pD 6.95. Nonlinear protein concentration dependences were observed for the oxygen-17 NMR transverse relaxation rates, but the fitting of the data did not require any higher order virial coefficients ; only B 0 was needed. This indicates that long-range, charge-charge repulsive interactions dominate entirely the protein activity in solution. Estimates of the bovine casein average net charge were obtained from the virial coefficient (B 0 ) and the partial specific volume ; these are in accord with published amino acid sequence data. For bovine casein, the α s1 - and β-components occur in nearly equal amounts, whereas in caprine casein, β-casein is the predominant species and α s1 -casein varies from high to low values, suggesting altered protein-protein interactions. Hydration levels of caprine casein high in the α s1 -casein component when compared with those of bovine casein (intermediate hydration) and the low α s1 -caprine casein (low hydration) are interpreted in terms of trapped water and preferential interactions with water on the basis of quantitative differences in casein monomer contents.
Kazuyoshi Suenari - One of the best experts on this subject based on the ideXlab platform.
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the distance between the vein and lesions predicts the requirement of carina ablation in circumferential pulmonary vein isolation
Europace, 2011Co-Authors: Hsuan Ming Tsao, Chien Jung Chang, Wen Chin Tsai, Shih-lin Chang, Li Wei Lo, Yu-feng Hu, Ta Chuan Tuan, Kazuyoshi SuenariAbstract:Aims Additional ablation in the pulmonary vein (PV) carina region is sometimes required to achieve electrical isolation following circumferential pulmonary vein isolation (PVI). This study investigated the procedural predictors for the requirement of additional carina ablation to achieve complete electrical isolation with PVI. Methods and results Eighty patients with drug-refractory paroxysmal AF underwent circumferential PVI. After the first round of PVI, we placed circular catheters inside the veins to identify the residual PV potentials, and also performed electroanatomic mapping to observe the earliest activation sites during sinus rhythm. The requirement of an additional gap and carina ablation, and the optimal distance that predicted an incomplete PV block were assessed. In the first 40 patients, 43% of the ipsilateral PVs were electrically isolated after the initial PVI. Subsequent ablation of the gaps and ablation of the carina were required in the remaining 57% PVs. The only predictor of the requirement of carina ablation was the mean distance between the lesion-related scar and the ostia ( P = 0.03). The longer the distance from the isolating lesions to the PV ostia (>8 mm) predicted an incomplete PV isolation after the first round of circumferential isolation. In the next 40 patients, a fixed distance of 8 mm to the PV ostia decreased the requirement of a carina ablation and resulted in a shorter procedure time ( P < 0.05). Conclusions This study indicated the importance of complete linear lesions and additional carina ablation when the wide area circumferential PV isolation was applied.
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The distance between the vein and lesions predicts the requirement of carina ablation in circumferential pulmonary vein isolation
Europace, 2011Co-Authors: Yenn Jiang Lin, Chien Jung Chang, Ching Tai Tai, Wen Chin Tsai, Shih-lin Chang, Li Wei Lo, Yu-feng Hu, Ta Chuan Tuan, Hsuan Ming Tsao, Kazuyoshi SuenariAbstract:Additional ablation in the pulmonary vein (PV) carina region is sometimes required to achieve electrical isolation following circumferential pulmonary vein isolation (PVI). This study investigated the procedural predictors for the requirement of additional carina ablation to achieve complete electrical isolation with PVI.
