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Paul N Durrington – One of the best experts on this subject based on the ideXlab platform.

Bharti Mackness – One of the best experts on this subject based on the ideXlab platform.

  • effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS Letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P<0.01) and PON1-RR HDL retained only 0.75±0.40% (P<0.005). In similar experiments HDL from LL and LM genotypes retained 21.8±7.5% and 29.5±6.6% (P=NS), respectively, of their protective ability, whereas PON1-MM HDL maintained 49.5±5.3% (P<0.01). PON1 polymorphisms may affect the ability of HDL to impede the development of atherosclerosis and to prevent inflammation.

  • Effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P

  • effect of the molecular polymorphisms of human paraoxonase pon1 on the rate of hydrolysis of paraoxon
    British Journal of Pharmacology, 1997
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    1 The hydrolysis of organophosphate pesticides (OP) and nerve gases by serum paraoxonase (PON1) is an important factor determining their toxicity to mammals including man. The PON1 gene contains 2 polymorphic sites at amino acid positions 55 (LM) and 192 (GA, classically defined as the A and B genotypes) which result in several Alloenzymes of PON1 in human serum. 2 The 192 polymorphism has previously been shown to affect PON1 activity. We have investigated the effect of both polymorphisms on the hydrolysis of paraoxon by serum from 279 healthy human subjects. 3 The 55 polymorphism significantly influenced PON1 activity. MM homozygotes had over 50% less activity towards paraoxon compared to the LL and LM genotypes regardless of the 192 genotype (P<0.001). 4 Multiple regression analysis indicated that the 192 polymorphism, 55 polymorphism and serum PON1 concentration were responsible for 46, 16 and 13% of the variation in PON1 activity, respectively (all P<0.001). None of the other parameters investigated significantly affected PON1 activity. 5 Therefore both PON1 polymorphisms affect the hydrolysis of paraoxon. AA/MM and AB/MM individuals may be potentially more susceptible to OP intoxication. 6 Genotyping individuals for both PON1 polymorphisms may provide a method for identifying those individuals at most risk of OP poisoning. The effect of PON1 polymorphisms on activity may also explain why some Gulf War Veterans have developed Gulf War Syndrome and some have not. British Journal of Pharmacology (1997) 122, 265–268; doi:10.1038/sj.bjp.0701390

Michael I Mackness – One of the best experts on this subject based on the ideXlab platform.

  • effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS Letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P<0.01) and PON1-RR HDL retained only 0.75±0.40% (P<0.005). In similar experiments HDL from LL and LM genotypes retained 21.8±7.5% and 29.5±6.6% (P=NS), respectively, of their protective ability, whereas PON1-MM HDL maintained 49.5±5.3% (P<0.01). PON1 polymorphisms may affect the ability of HDL to impede the development of atherosclerosis and to prevent inflammation.

  • Effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P

  • effect of the molecular polymorphisms of human paraoxonase pon1 on the rate of hydrolysis of paraoxon
    British Journal of Pharmacology, 1997
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    1 The hydrolysis of organophosphate pesticides (OP) and nerve gases by serum paraoxonase (PON1) is an important factor determining their toxicity to mammals including man. The PON1 gene contains 2 polymorphic sites at amino acid positions 55 (LM) and 192 (GA, classically defined as the A and B genotypes) which result in several Alloenzymes of PON1 in human serum. 2 The 192 polymorphism has previously been shown to affect PON1 activity. We have investigated the effect of both polymorphisms on the hydrolysis of paraoxon by serum from 279 healthy human subjects. 3 The 55 polymorphism significantly influenced PON1 activity. MM homozygotes had over 50% less activity towards paraoxon compared to the LL and LM genotypes regardless of the 192 genotype (P<0.001). 4 Multiple regression analysis indicated that the 192 polymorphism, 55 polymorphism and serum PON1 concentration were responsible for 46, 16 and 13% of the variation in PON1 activity, respectively (all P<0.001). None of the other parameters investigated significantly affected PON1 activity. 5 Therefore both PON1 polymorphisms affect the hydrolysis of paraoxon. AA/MM and AB/MM individuals may be potentially more susceptible to OP intoxication. 6 Genotyping individuals for both PON1 polymorphisms may provide a method for identifying those individuals at most risk of OP poisoning. The effect of PON1 polymorphisms on activity may also explain why some Gulf War Veterans have developed Gulf War Syndrome and some have not. British Journal of Pharmacology (1997) 122, 265–268; doi:10.1038/sj.bjp.0701390

S Arrol – One of the best experts on this subject based on the ideXlab platform.

  • effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS Letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P<0.01) and PON1-RR HDL retained only 0.75±0.40% (P<0.005). In similar experiments HDL from LL and LM genotypes retained 21.8±7.5% and 29.5±6.6% (P=NS), respectively, of their protective ability, whereas PON1-MM HDL maintained 49.5±5.3% (P<0.01). PON1 polymorphisms may affect the ability of HDL to impede the development of atherosclerosis and to prevent inflammation.

  • Effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P

  • effect of the molecular polymorphisms of human paraoxonase pon1 on the rate of hydrolysis of paraoxon
    British Journal of Pharmacology, 1997
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    1 The hydrolysis of organophosphate pesticides (OP) and nerve gases by serum paraoxonase (PON1) is an important factor determining their toxicity to mammals including man. The PON1 gene contains 2 polymorphic sites at amino acid positions 55 (LM) and 192 (GA, classically defined as the A and B genotypes) which result in several Alloenzymes of PON1 in human serum. 2 The 192 polymorphism has previously been shown to affect PON1 activity. We have investigated the effect of both polymorphisms on the hydrolysis of paraoxon by serum from 279 healthy human subjects. 3 The 55 polymorphism significantly influenced PON1 activity. MM homozygotes had over 50% less activity towards paraoxon compared to the LL and LM genotypes regardless of the 192 genotype (P<0.001). 4 Multiple regression analysis indicated that the 192 polymorphism, 55 polymorphism and serum PON1 concentration were responsible for 46, 16 and 13% of the variation in PON1 activity, respectively (all P<0.001). None of the other parameters investigated significantly affected PON1 activity. 5 Therefore both PON1 polymorphisms affect the hydrolysis of paraoxon. AA/MM and AB/MM individuals may be potentially more susceptible to OP intoxication. 6 Genotyping individuals for both PON1 polymorphisms may provide a method for identifying those individuals at most risk of OP poisoning. The effect of PON1 polymorphisms on activity may also explain why some Gulf War Veterans have developed Gulf War Syndrome and some have not. British Journal of Pharmacology (1997) 122, 265–268; doi:10.1038/sj.bjp.0701390

Wajdi Turkie – One of the best experts on this subject based on the ideXlab platform.

  • effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS Letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P<0.01) and PON1-RR HDL retained only 0.75±0.40% (P<0.005). In similar experiments HDL from LL and LM genotypes retained 21.8±7.5% and 29.5±6.6% (P=NS), respectively, of their protective ability, whereas PON1-MM HDL maintained 49.5±5.3% (P<0.01). PON1 polymorphisms may affect the ability of HDL to impede the development of atherosclerosis and to prevent inflammation.

  • Effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification
    FEBS letters, 1998
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    Human serum paraoxonase (PON1) associated with high density lipoprotein (HDL) has been postulated to have a role in protecting low density lipoprotein (LDL) against oxidative modification, which has led to the proposal that PON1 is an anti-atherogenic, anti-inflammatory enzyme. PON1 has two genetically determined polymorphic sites giving rise to amino-acid substitutions at positions 55 (L→M) and 192 (R→Q) and therefore 4 potential Alloenzymes. We have examined the effects of these molecular polymorphisms on the ability of HDL to protect LDL from oxidative modification. HDL protected LDL from oxidative modification, whatever the combination of PON1 Alloenzymes present in it. However, HDL from QQ/MM homozygotes was most effective at protecting LDL while HDL from RR/LL homozygotes was least effective. Thus after 6 h of co-incubation of HDL and LDL with Cu2+ PON1-QQ HDL retained 57±6.3% of its original ability to protect LDL from oxidative modification, while PON1-QR HDL retained less at 25.1±4.5% (P

  • effect of the molecular polymorphisms of human paraoxonase pon1 on the rate of hydrolysis of paraoxon
    British Journal of Pharmacology, 1997
    Co-Authors: Bharti Mackness, Michael I Mackness, S Arrol, Wajdi Turkie, Paul N Durrington
    Abstract:

    1 The hydrolysis of organophosphate pesticides (OP) and nerve gases by serum paraoxonase (PON1) is an important factor determining their toxicity to mammals including man. The PON1 gene contains 2 polymorphic sites at amino acid positions 55 (LM) and 192 (GA, classically defined as the A and B genotypes) which result in several Alloenzymes of PON1 in human serum. 2 The 192 polymorphism has previously been shown to affect PON1 activity. We have investigated the effect of both polymorphisms on the hydrolysis of paraoxon by serum from 279 healthy human subjects. 3 The 55 polymorphism significantly influenced PON1 activity. MM homozygotes had over 50% less activity towards paraoxon compared to the LL and LM genotypes regardless of the 192 genotype (P<0.001). 4 Multiple regression analysis indicated that the 192 polymorphism, 55 polymorphism and serum PON1 concentration were responsible for 46, 16 and 13% of the variation in PON1 activity, respectively (all P<0.001). None of the other parameters investigated significantly affected PON1 activity. 5 Therefore both PON1 polymorphisms affect the hydrolysis of paraoxon. AA/MM and AB/MM individuals may be potentially more susceptible to OP intoxication. 6 Genotyping individuals for both PON1 polymorphisms may provide a method for identifying those individuals at most risk of OP poisoning. The effect of PON1 polymorphisms on activity may also explain why some Gulf War Veterans have developed Gulf War Syndrome and some have not. British Journal of Pharmacology (1997) 122, 265–268; doi:10.1038/sj.bjp.0701390