Abdelouahed Khalil - Academia.edu (original) (raw)

Papers by Abdelouahed Khalil

Diabetes Research and …, 2010

The Journal of Nutrition, Health & …

... Acknowledgements: We would like to thank all the subjects who have participated in this study... more ... Acknowledgements: We would like to thank all the subjects who have participated in this study as well as Martine Fisch (RN) for her valuable assistance. This study was funded by the Canadian Diabetes Association. The vitamin ...

American journal of nuclear medicine and molecular imaging, 2014

This study was aimed to investigate the usefulness of (18)F-FDG-PET to differentiate vascular inf... more This study was aimed to investigate the usefulness of (18)F-FDG-PET to differentiate vascular inflammation and to determine the effect of rosuvastatin. Eight subjects were recruited and were divided according to their health status in three groups; 3 healthy subjects, 3 patients with hypercholesterolemia and 2 patients with stable angina pectoris. Hypercholesterolemic patients were submitted immediately after their recruitment to rosuvastatin treatment (20 mg/d). Two PET/CT measurements were made throughout the course of the study, one at baseline and the second 12 months later. Our results showed that the ratio of calcified arteries to total analyzed arteries segments were 23%, 36% and 44% for healthy, hypercholesterolemic and stable angina patients respectively. Healthy subjects present, at baseline, a high level of vascular inflammation as measured by (18)F-FDG uptake in both calcified and non-calcified segments of the arteries. This vascular inflammation increases as a function ...

The aim of this study was to examine the effects of resistance training on hematological blood ma... more The aim of this study was to examine the effects of resistance training on hematological blood markers in older individuals. Twenty-nine men and women participated to this study. Subjects were randomized in 2 groups: (1) control (n = 13) and (2) resistance training (n = 16). At baseline and after the intervention, subjects were submitted to a blood sample to determine their hematological profile (red blood cells, hemoglobin, hematocrit, platelets, leukocytes, neutrophils, lymphocytes, monocytes, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width). At baseline, no difference was observed between groups. Moreover, we found no significant difference after the intervention on any of these markers. A 6-month resistance program in healthy older individuals seems to have no beneficial nor deleterious effects on hematological blood parameters. However, resistance training was well tolerated and should be recommended for other health purposes. Further studies are needed to confirm these results in a large population.

Nutrition Metabolism and Cardiovascular Diseases, 2005

Nutrition, Metabolism & Cardiovascular Diseases (2005) --,ewww.elsevier.com/locate/nmcd VAO group... more Nutrition, Metabolism & Cardiovascular Diseases (2005) --,ewww.elsevier.com/locate/nmcd VAO group (P Z 0.007). Susceptibility of LDL to lipid peroxidation shows a significant increase in lag phase and a significant decrease in maximum diene production in VAO (P Z 0.005) and EVO groups (P Z 0.041 and P Z 0.005, respectively). Conclusions: Our findings confirm the beneficial effect of EVO on plasma antioxidant status and show for the first time the same effect for VAO supplementation in man. Thus, VAO offers an additional natural food supplement to reduce cardiovascular risk. ª

Radiation Research, 2012

Cystamine, an organic disulfide (RSSR), is among the best of the known radiation-protective compo... more Cystamine, an organic disulfide (RSSR), is among the best of the known radiation-protective compounds and has been used to protect normal tissues in clinical radiation therapy. Recently, it has also proved to be beneficial in the treatment of disorders of the central nervous system in animal models. However, the underlying mechanism of its action at the chemical level is not yet well understood. The present study aims at using the ferrous sulfate (Fricke) dosimeter to quantitatively evaluate, both experimentally and theoretically, the radioprotective potential of this compound. The well-known radiolysis of the Fricke dosimeter by (60)Co γ rays or fast electrons, based on the oxidation of ferrous ions to ferric ions by the oxidizing species (•)OH, HO(2)(•), and H(2)O(2) produced in the radiolytic decomposition of water, forms the basis for our method. The presence of cystamine in Fricke dosimeter solutions during irradiation prevents the radiolytic oxidation of Fe(2+) and leads to decreased ferric yields (or G values). The observed decrease in G(Fe(3+)) increases upon increasing the concentration of the disulfide compound over the range 0-0.1 M under both aerated and deaerated conditions. To help assess the basic radiation-protective mechanism of this compound, a full Monte Carlo computer code is developed to simulate in complete detail the radiation-induced chemistry of the studied Fricke/cystamine solutions. Benefiting from the fact that cystamine is reasonably well characterized in terms of radiation chemistry, this computer model proposes reaction mechanisms and incorporates specific reactions describing the radiolysis of cystamine in aerated and deaerated Fricke solutions that lead to the observable quantitative chemical yields. Results clearly indicate that the protective effect of cystamine originates from its radical-capturing ability, which allows this compound to act by competing with the ferrous ions for the various free radicals--especially (•)OH radicals and H(•) atoms--formed during irradiation of the surrounding water. Most interestingly, our simulation modeling also shows that the predominant pathway in the oxidation of cystamine by (•)OH radicals involves an electron-transfer mechanism, yielding RSSR(•+) and OH(-). A very good agreement is found between calculated G(Fe(3+)) values and experiment. This study concludes that Monte Carlo simulations represent a very efficient method for understanding indirect radiation damage at the molecular level.

Radiation Physics and Chemistry, 2005

Physics in Medicine and Biology, 2009

In this study, polyacrylamide gel (PAG) dosimetry is used to quantitatively assess the efficiency... more In this study, polyacrylamide gel (PAG) dosimetry is used to quantitatively assess the efficiency of radiation sensitizers. The local dose enhancement caused by the K-edge absorption of certain atoms such as bromine and iodine can be employed to increase the damage to neighboring molecules and cells. Clonogenic assays can assess the radiation survival of cells to evaluate the efficiency of radiation sensitizers, but this technique requires reliable cell growth in culture media and is time consuming. Our purpose is to use PAG dosimetry to investigate the sensitizing potential of radiation sensitizers such as iodinated compounds. Incorporation of iodinated radiation sensitizers such as NaI and an iodinated contrast agent leads to a quantifiable dose enhancement ratio. When irradiated at low energy (approximately 40 keV), the dose enhancement ratio of the iodinated contrast agent at concentrations of 0.01 (3.5 mg ml(-1)), 0.05 (6 mg ml(-1)) and 0.1 (12 mg ml(-1)) M are 1.16 +/- 0.02, 1.39 +/- 0.03 and 1.82 +/- 0.04, respectively. No dose enhancement was observed when the samples were irradiated with 1.25 MeV gamma photons.

Pharmacological Research, 2006

The present work describes the mechanisms involved in the vasorelaxant effect of harmine and harm... more The present work describes the mechanisms involved in the vasorelaxant effect of harmine and harmaline. These alkaloids induce in a dose-dependent manner the relaxation in the aorta precontracted with noradrenaline or KCl. However, the removal of endothelium or pre-treatment of intact aortic ring with L-NAME (inhibitor of NOSe synthetase) or with indomethacin (non-specific inhibitor of cyclo-oxygenase), reduces significantly the vasorelaxant response of harmaline but not harmine. According to their IC50 values, prazosin (inhibitor of alpha-adrenorecepteors) reduces the vasorelaxant effect only of harmaline, whereas, pre-treatment with IBMX (non-specific inhibitor of phosphodiesterase) affects both the harmaline and harmine-responses. Inhibitions of L-type voltage-dependent Ca2+ channels (VOCs) in endothelium-intact aortic rings with diltiazem depress the relaxation evoked by harmaline as well as by harmine. Pre-treatment with harmaline or harmine (3, 10 or 30 microM) shifted the phenylephrine-induced dose response curves to the right and the maximum response was attenuated indicating that the antagonist effect of both alkaloids on alpha1-adrenorecepteors was non-competitive. These two alkaloids also exert an antioxidant activity by scavenging the free radical generated by DPPH. Therefore, the present results suggest that the vasorelaxant effect of harmaline but not harmine is related to its action on the prostacyclin pathway and on the endothelial cells to release NO. However, both alkaloids can act as blockers VOCs, as inhibitors of phosphodiesterase resulting in an increase of the second messenger (cAMP and cGMP) levels and finally reduce the levels of free radicals in tissues.

Pharmacological Research, 2006

Aim: The argan oil, extracted from argan-tree fruits, has been known for its various pharmacologi... more Aim: The argan oil, extracted from argan-tree fruits, has been known for its various pharmacological properties and used as a natural remedy since several centuries. In this review, we present a summary of the results obtained from a survey of the literature on argan oil. Data synthesis: Various studies conducted in vitro or on human and animal models suggest that argan oil could play a beneficial role in cardiovascular diseases prevention and its consumption could protect against atherosclerosis and cancer via a variety of biological mechanisms. Conclusion: Argan oil reduces cardiovascular risk and may be used as anti-atherogenic oil.

Pathologie Biologie, 2005

The degradation products of one of the major component of vascular wall, elastin, have several im... more The degradation products of one of the major component of vascular wall, elastin, have several important biological activities. Elastin peptides (KE) are mostly generated during vascular aging and the atherosclerotic process. They induce free radical and proteases production from cells, which are the major components of the atherosclerotic process. In the present study, we investigated whether the interaction between elastin peptides and neutrophils as well as monocytes contributes to low density lipoproteins (LDL) oxidation, being one of the most important initiator of the chronic inflammatory process contributing to the development of atherosclerosis. Here, we present data on the link between the elastin degradation products and LDL oxidation by the chemotactically attracted neutrophils and monocytes. The KE as well as the active epitope, the hexapeptide VGVAPG is able, in a differential concentration and time dependence, to induce the oxidation of LDL. KE is able to induce via the production of free radicals by neutrophils the oxidation of LDL very rapidly and in higher concentration compared to monocytes. These effects of KE are occurring through the stimulation of the 67 kDa elastin-laminin receptor (ELR), as demonstrated by the uncoupling effect of lactose. In our present study, the HDL was able to decrease the LDL oxidation by KE. This is a new mechanism by which elastin peptides might participate in the initiation and progression of the atherosclerotic process.

Obesity, 2006

AUBERTIN-LEHEUDRE, MYLÈ NE, CHRISTINE LORD, É RIC D.B. GOULET, ABDELOUAHED KHALIL, AND ISABELLE J... more AUBERTIN-LEHEUDRE, MYLÈ NE, CHRISTINE LORD, É RIC D.B. GOULET, ABDELOUAHED KHALIL, AND ISABELLE J. DIONNE. Effect of sarcopenia on cardiovascular disease risk factors in obese postmenopausal women. Obesity. 2006;14:2277-2283.

Microscopy Research and Technique, 2007

This short paper reports a simple method to image low density lipoproteins (LDL) using atomic for... more This short paper reports a simple method to image low density lipoproteins (LDL) using atomic force microscopy (AFM). This instrument allows imaging of biological samples in liquid and presents the advantage of needing no sample preparation such as staining or fixation that may affect their general structure. Dimensions (diameter and height) of individual LDL particles were successfully measured. AFM imaging revealed that LDL have a quasi-spherical structure on the x and y axis with an oblate spheroid structure in the z axis (i.e., height). LDLs were found to have an average diameter of 23 +/- 3 nm. The obtained mean height was 10 +/- 2 nm.

Menopause, 2007

Objective: To investigate whether 6 months of exercise combined with isoflavone supplementation c... more Objective: To investigate whether 6 months of exercise combined with isoflavone supplementation could improve clinical risk factors that predispose to cardiovascular disease in obese postmenopausal women.

Medicine & Science in Sports & Exercise, 2010

We sought to determine if a small muscle mass index (MMI) is actually detrimental for insulin sen... more We sought to determine if a small muscle mass index (MMI) is actually detrimental for insulin sensitivity when studying a large group of postmenopausal women displaying various body composition statuses and when age and visceral fat mass (VFM) are taken into account. Methods: A cross-sectional study was conducted in 99 healthy postmenopausal women with a BMI of 28±4 kg/m 2 . Fat mass and total fat-free mass (FFM) were obtained from DXA and VFM and MMI were estimated respectively by the equation of Bertin and by: Total FFM (kg)/height (m) 2 . Fasting plasma insulin and glucose were obtained to calculate QUICKI and HOMA as an insulin sensitivity index. Results: Total MMI and VFM were both significantly inversely correlated with QUICKI and positively with HOMA even when adjusted for VFM. A stepwise linear regression confirmed Total MMI and VFM as independent predictors of HOMA and plasma insulin level. Conclusions: A small muscle mass might not be detrimental for the maintenance of insulin sensitivity and could even be beneficial in sedentary postmenopausal women. The impact of muscle mass loss on insulin sensitivity in older adults needs to be further investigated.

Mechanisms of Ageing and Development, 1997

Many alterations with aging occur at the cellular and organic levels in the immune system ultimat... more Many alterations with aging occur at the cellular and organic levels in the immune system ultimately leading to a decrease in the immune response. Our aim in the present work was to study apoptosis of polymorphonuclear granulocytes (PMN) with aging under various stimulations since ...

Mechanisms of Ageing and Development, 2012

Journal of Women's Health, 2008

To investigate whether 6 months of isoflavone supplementation, which has been shown to be suffici... more To investigate whether 6 months of isoflavone supplementation, which has been shown to be sufficient to improve menopausal symptoms, could also improve clinical cardiovascular disease (CVD) risk factors in obese postmenopausal women, compared with a placebo. Methods: A randomized double-blind placebo-controlled trial in which 50 obese postmenopausal women were divided into two groups (isoflavones vs. placebo) to examine the effect of 6 months of isoflavone supplement (70 mg) on clinical CVD risk factors. Body composition (DXA), medical and social characteristics, daily energy expenditure (accelerometry), dietary intake (3-day dietary record), and blood biochemical analyses (lipid profile, insulin, glucose) were obtained. Results: At baseline, no differences were found between groups except for fasting insulin level. Women were thus considered at risk of CVD based on body composition but not biochemical variables. After 6 months, we observed that isoflavones did not favorably affect risk factors predisposing to CVD (biochemical or body composition) compared with placebo. Conclusions: Isoflavones given for 6 months should not be considered protective against clinical CVD risk factors in obese postmenopausal women. Nevertheless, further research is needed to verify if isoflavones protect against CVD disease risk factors when administered for a longer duration or when combined with nutritional or exercise interventions. It would also be pertinent to study their effects in women with specific metabolic abnormalities.

Journal of Women & Aging, 2008

It is known that obesity is inversely correlated with fracture risk. It remains unclear if a low ... more It is known that obesity is inversely correlated with fracture risk. It remains unclear if a low muscle mass (sarcopenia) modulates the relationship between obesity and bone mass density. Twenty-seven obese women were matched for total fat mass (± 0.5 kg) and age (± 4 yrs) and divided in 3 equal groups: class II sarcopenic, class I sarcopenic, and nonsarcopenic. Body composition (DXA) and dietary intake were measured. Our results suggest that obesity may offer some protection against osteoporosis, even in sarcopenic postmenopausal women. However, further

Journal of the American Geriatrics Society, 2000

To the Editor: Although resistance training is promoted to increase fat-free mass (FFM) in older ... more To the Editor: Although resistance training is promoted to increase fat-free mass (FFM) in older adults, 1 50% of clinical trials report no meaningful effects of resistance training on FFM in older persons. 2 One potential explanation is that oxidative stress, which characterizes the process of aging, may minimize the adaptations to resistance exercise 3 and may attenuate muscle cell hypertrophy. Although regular exercise training enhances adaptive responses, thereby diminishing oxidative stress in younger individuals, 4 it appears that aging may attenuate these adaptations. 5 It thus has been proposed that elderly people who exercise have a greater dietary antioxidant requirement, 6 especially for vitamin E. To our knowledge, no studies have specifically examined changes in FFM in response to high-intensity resistance training combined with dietary antioxidants in older men and women. The purpose of this study was to investigate whether 6 months of resistance training combined with antioxidant treatment could produce greater increases in FFM than one or no intervention.

Diabetes Research and …, 2010

The Journal of Nutrition, Health & …

... Acknowledgements: We would like to thank all the subjects who have participated in this study... more ... Acknowledgements: We would like to thank all the subjects who have participated in this study as well as Martine Fisch (RN) for her valuable assistance. This study was funded by the Canadian Diabetes Association. The vitamin ...

American journal of nuclear medicine and molecular imaging, 2014

This study was aimed to investigate the usefulness of (18)F-FDG-PET to differentiate vascular inf... more This study was aimed to investigate the usefulness of (18)F-FDG-PET to differentiate vascular inflammation and to determine the effect of rosuvastatin. Eight subjects were recruited and were divided according to their health status in three groups; 3 healthy subjects, 3 patients with hypercholesterolemia and 2 patients with stable angina pectoris. Hypercholesterolemic patients were submitted immediately after their recruitment to rosuvastatin treatment (20 mg/d). Two PET/CT measurements were made throughout the course of the study, one at baseline and the second 12 months later. Our results showed that the ratio of calcified arteries to total analyzed arteries segments were 23%, 36% and 44% for healthy, hypercholesterolemic and stable angina patients respectively. Healthy subjects present, at baseline, a high level of vascular inflammation as measured by (18)F-FDG uptake in both calcified and non-calcified segments of the arteries. This vascular inflammation increases as a function ...

The aim of this study was to examine the effects of resistance training on hematological blood ma... more The aim of this study was to examine the effects of resistance training on hematological blood markers in older individuals. Twenty-nine men and women participated to this study. Subjects were randomized in 2 groups: (1) control (n = 13) and (2) resistance training (n = 16). At baseline and after the intervention, subjects were submitted to a blood sample to determine their hematological profile (red blood cells, hemoglobin, hematocrit, platelets, leukocytes, neutrophils, lymphocytes, monocytes, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width). At baseline, no difference was observed between groups. Moreover, we found no significant difference after the intervention on any of these markers. A 6-month resistance program in healthy older individuals seems to have no beneficial nor deleterious effects on hematological blood parameters. However, resistance training was well tolerated and should be recommended for other health purposes. Further studies are needed to confirm these results in a large population.

Nutrition Metabolism and Cardiovascular Diseases, 2005

Nutrition, Metabolism & Cardiovascular Diseases (2005) --,ewww.elsevier.com/locate/nmcd VAO group... more Nutrition, Metabolism & Cardiovascular Diseases (2005) --,ewww.elsevier.com/locate/nmcd VAO group (P Z 0.007). Susceptibility of LDL to lipid peroxidation shows a significant increase in lag phase and a significant decrease in maximum diene production in VAO (P Z 0.005) and EVO groups (P Z 0.041 and P Z 0.005, respectively). Conclusions: Our findings confirm the beneficial effect of EVO on plasma antioxidant status and show for the first time the same effect for VAO supplementation in man. Thus, VAO offers an additional natural food supplement to reduce cardiovascular risk. ª

Radiation Research, 2012

Cystamine, an organic disulfide (RSSR), is among the best of the known radiation-protective compo... more Cystamine, an organic disulfide (RSSR), is among the best of the known radiation-protective compounds and has been used to protect normal tissues in clinical radiation therapy. Recently, it has also proved to be beneficial in the treatment of disorders of the central nervous system in animal models. However, the underlying mechanism of its action at the chemical level is not yet well understood. The present study aims at using the ferrous sulfate (Fricke) dosimeter to quantitatively evaluate, both experimentally and theoretically, the radioprotective potential of this compound. The well-known radiolysis of the Fricke dosimeter by (60)Co γ rays or fast electrons, based on the oxidation of ferrous ions to ferric ions by the oxidizing species (•)OH, HO(2)(•), and H(2)O(2) produced in the radiolytic decomposition of water, forms the basis for our method. The presence of cystamine in Fricke dosimeter solutions during irradiation prevents the radiolytic oxidation of Fe(2+) and leads to decreased ferric yields (or G values). The observed decrease in G(Fe(3+)) increases upon increasing the concentration of the disulfide compound over the range 0-0.1 M under both aerated and deaerated conditions. To help assess the basic radiation-protective mechanism of this compound, a full Monte Carlo computer code is developed to simulate in complete detail the radiation-induced chemistry of the studied Fricke/cystamine solutions. Benefiting from the fact that cystamine is reasonably well characterized in terms of radiation chemistry, this computer model proposes reaction mechanisms and incorporates specific reactions describing the radiolysis of cystamine in aerated and deaerated Fricke solutions that lead to the observable quantitative chemical yields. Results clearly indicate that the protective effect of cystamine originates from its radical-capturing ability, which allows this compound to act by competing with the ferrous ions for the various free radicals--especially (•)OH radicals and H(•) atoms--formed during irradiation of the surrounding water. Most interestingly, our simulation modeling also shows that the predominant pathway in the oxidation of cystamine by (•)OH radicals involves an electron-transfer mechanism, yielding RSSR(•+) and OH(-). A very good agreement is found between calculated G(Fe(3+)) values and experiment. This study concludes that Monte Carlo simulations represent a very efficient method for understanding indirect radiation damage at the molecular level.

Radiation Physics and Chemistry, 2005

Physics in Medicine and Biology, 2009

In this study, polyacrylamide gel (PAG) dosimetry is used to quantitatively assess the efficiency... more In this study, polyacrylamide gel (PAG) dosimetry is used to quantitatively assess the efficiency of radiation sensitizers. The local dose enhancement caused by the K-edge absorption of certain atoms such as bromine and iodine can be employed to increase the damage to neighboring molecules and cells. Clonogenic assays can assess the radiation survival of cells to evaluate the efficiency of radiation sensitizers, but this technique requires reliable cell growth in culture media and is time consuming. Our purpose is to use PAG dosimetry to investigate the sensitizing potential of radiation sensitizers such as iodinated compounds. Incorporation of iodinated radiation sensitizers such as NaI and an iodinated contrast agent leads to a quantifiable dose enhancement ratio. When irradiated at low energy (approximately 40 keV), the dose enhancement ratio of the iodinated contrast agent at concentrations of 0.01 (3.5 mg ml(-1)), 0.05 (6 mg ml(-1)) and 0.1 (12 mg ml(-1)) M are 1.16 +/- 0.02, 1.39 +/- 0.03 and 1.82 +/- 0.04, respectively. No dose enhancement was observed when the samples were irradiated with 1.25 MeV gamma photons.

Pharmacological Research, 2006

The present work describes the mechanisms involved in the vasorelaxant effect of harmine and harm... more The present work describes the mechanisms involved in the vasorelaxant effect of harmine and harmaline. These alkaloids induce in a dose-dependent manner the relaxation in the aorta precontracted with noradrenaline or KCl. However, the removal of endothelium or pre-treatment of intact aortic ring with L-NAME (inhibitor of NOSe synthetase) or with indomethacin (non-specific inhibitor of cyclo-oxygenase), reduces significantly the vasorelaxant response of harmaline but not harmine. According to their IC50 values, prazosin (inhibitor of alpha-adrenorecepteors) reduces the vasorelaxant effect only of harmaline, whereas, pre-treatment with IBMX (non-specific inhibitor of phosphodiesterase) affects both the harmaline and harmine-responses. Inhibitions of L-type voltage-dependent Ca2+ channels (VOCs) in endothelium-intact aortic rings with diltiazem depress the relaxation evoked by harmaline as well as by harmine. Pre-treatment with harmaline or harmine (3, 10 or 30 microM) shifted the phenylephrine-induced dose response curves to the right and the maximum response was attenuated indicating that the antagonist effect of both alkaloids on alpha1-adrenorecepteors was non-competitive. These two alkaloids also exert an antioxidant activity by scavenging the free radical generated by DPPH. Therefore, the present results suggest that the vasorelaxant effect of harmaline but not harmine is related to its action on the prostacyclin pathway and on the endothelial cells to release NO. However, both alkaloids can act as blockers VOCs, as inhibitors of phosphodiesterase resulting in an increase of the second messenger (cAMP and cGMP) levels and finally reduce the levels of free radicals in tissues.

Pharmacological Research, 2006

Aim: The argan oil, extracted from argan-tree fruits, has been known for its various pharmacologi... more Aim: The argan oil, extracted from argan-tree fruits, has been known for its various pharmacological properties and used as a natural remedy since several centuries. In this review, we present a summary of the results obtained from a survey of the literature on argan oil. Data synthesis: Various studies conducted in vitro or on human and animal models suggest that argan oil could play a beneficial role in cardiovascular diseases prevention and its consumption could protect against atherosclerosis and cancer via a variety of biological mechanisms. Conclusion: Argan oil reduces cardiovascular risk and may be used as anti-atherogenic oil.

Pathologie Biologie, 2005

The degradation products of one of the major component of vascular wall, elastin, have several im... more The degradation products of one of the major component of vascular wall, elastin, have several important biological activities. Elastin peptides (KE) are mostly generated during vascular aging and the atherosclerotic process. They induce free radical and proteases production from cells, which are the major components of the atherosclerotic process. In the present study, we investigated whether the interaction between elastin peptides and neutrophils as well as monocytes contributes to low density lipoproteins (LDL) oxidation, being one of the most important initiator of the chronic inflammatory process contributing to the development of atherosclerosis. Here, we present data on the link between the elastin degradation products and LDL oxidation by the chemotactically attracted neutrophils and monocytes. The KE as well as the active epitope, the hexapeptide VGVAPG is able, in a differential concentration and time dependence, to induce the oxidation of LDL. KE is able to induce via the production of free radicals by neutrophils the oxidation of LDL very rapidly and in higher concentration compared to monocytes. These effects of KE are occurring through the stimulation of the 67 kDa elastin-laminin receptor (ELR), as demonstrated by the uncoupling effect of lactose. In our present study, the HDL was able to decrease the LDL oxidation by KE. This is a new mechanism by which elastin peptides might participate in the initiation and progression of the atherosclerotic process.

Obesity, 2006

AUBERTIN-LEHEUDRE, MYLÈ NE, CHRISTINE LORD, É RIC D.B. GOULET, ABDELOUAHED KHALIL, AND ISABELLE J... more AUBERTIN-LEHEUDRE, MYLÈ NE, CHRISTINE LORD, É RIC D.B. GOULET, ABDELOUAHED KHALIL, AND ISABELLE J. DIONNE. Effect of sarcopenia on cardiovascular disease risk factors in obese postmenopausal women. Obesity. 2006;14:2277-2283.

Microscopy Research and Technique, 2007

This short paper reports a simple method to image low density lipoproteins (LDL) using atomic for... more This short paper reports a simple method to image low density lipoproteins (LDL) using atomic force microscopy (AFM). This instrument allows imaging of biological samples in liquid and presents the advantage of needing no sample preparation such as staining or fixation that may affect their general structure. Dimensions (diameter and height) of individual LDL particles were successfully measured. AFM imaging revealed that LDL have a quasi-spherical structure on the x and y axis with an oblate spheroid structure in the z axis (i.e., height). LDLs were found to have an average diameter of 23 +/- 3 nm. The obtained mean height was 10 +/- 2 nm.

Menopause, 2007

Objective: To investigate whether 6 months of exercise combined with isoflavone supplementation c... more Objective: To investigate whether 6 months of exercise combined with isoflavone supplementation could improve clinical risk factors that predispose to cardiovascular disease in obese postmenopausal women.

Medicine & Science in Sports & Exercise, 2010

We sought to determine if a small muscle mass index (MMI) is actually detrimental for insulin sen... more We sought to determine if a small muscle mass index (MMI) is actually detrimental for insulin sensitivity when studying a large group of postmenopausal women displaying various body composition statuses and when age and visceral fat mass (VFM) are taken into account. Methods: A cross-sectional study was conducted in 99 healthy postmenopausal women with a BMI of 28±4 kg/m 2 . Fat mass and total fat-free mass (FFM) were obtained from DXA and VFM and MMI were estimated respectively by the equation of Bertin and by: Total FFM (kg)/height (m) 2 . Fasting plasma insulin and glucose were obtained to calculate QUICKI and HOMA as an insulin sensitivity index. Results: Total MMI and VFM were both significantly inversely correlated with QUICKI and positively with HOMA even when adjusted for VFM. A stepwise linear regression confirmed Total MMI and VFM as independent predictors of HOMA and plasma insulin level. Conclusions: A small muscle mass might not be detrimental for the maintenance of insulin sensitivity and could even be beneficial in sedentary postmenopausal women. The impact of muscle mass loss on insulin sensitivity in older adults needs to be further investigated.

Mechanisms of Ageing and Development, 1997

Many alterations with aging occur at the cellular and organic levels in the immune system ultimat... more Many alterations with aging occur at the cellular and organic levels in the immune system ultimately leading to a decrease in the immune response. Our aim in the present work was to study apoptosis of polymorphonuclear granulocytes (PMN) with aging under various stimulations since ...

Mechanisms of Ageing and Development, 2012

Journal of Women's Health, 2008

To investigate whether 6 months of isoflavone supplementation, which has been shown to be suffici... more To investigate whether 6 months of isoflavone supplementation, which has been shown to be sufficient to improve menopausal symptoms, could also improve clinical cardiovascular disease (CVD) risk factors in obese postmenopausal women, compared with a placebo. Methods: A randomized double-blind placebo-controlled trial in which 50 obese postmenopausal women were divided into two groups (isoflavones vs. placebo) to examine the effect of 6 months of isoflavone supplement (70 mg) on clinical CVD risk factors. Body composition (DXA), medical and social characteristics, daily energy expenditure (accelerometry), dietary intake (3-day dietary record), and blood biochemical analyses (lipid profile, insulin, glucose) were obtained. Results: At baseline, no differences were found between groups except for fasting insulin level. Women were thus considered at risk of CVD based on body composition but not biochemical variables. After 6 months, we observed that isoflavones did not favorably affect risk factors predisposing to CVD (biochemical or body composition) compared with placebo. Conclusions: Isoflavones given for 6 months should not be considered protective against clinical CVD risk factors in obese postmenopausal women. Nevertheless, further research is needed to verify if isoflavones protect against CVD disease risk factors when administered for a longer duration or when combined with nutritional or exercise interventions. It would also be pertinent to study their effects in women with specific metabolic abnormalities.

Journal of Women & Aging, 2008

It is known that obesity is inversely correlated with fracture risk. It remains unclear if a low ... more It is known that obesity is inversely correlated with fracture risk. It remains unclear if a low muscle mass (sarcopenia) modulates the relationship between obesity and bone mass density. Twenty-seven obese women were matched for total fat mass (± 0.5 kg) and age (± 4 yrs) and divided in 3 equal groups: class II sarcopenic, class I sarcopenic, and nonsarcopenic. Body composition (DXA) and dietary intake were measured. Our results suggest that obesity may offer some protection against osteoporosis, even in sarcopenic postmenopausal women. However, further

Journal of the American Geriatrics Society, 2000

To the Editor: Although resistance training is promoted to increase fat-free mass (FFM) in older ... more To the Editor: Although resistance training is promoted to increase fat-free mass (FFM) in older adults, 1 50% of clinical trials report no meaningful effects of resistance training on FFM in older persons. 2 One potential explanation is that oxidative stress, which characterizes the process of aging, may minimize the adaptations to resistance exercise 3 and may attenuate muscle cell hypertrophy. Although regular exercise training enhances adaptive responses, thereby diminishing oxidative stress in younger individuals, 4 it appears that aging may attenuate these adaptations. 5 It thus has been proposed that elderly people who exercise have a greater dietary antioxidant requirement, 6 especially for vitamin E. To our knowledge, no studies have specifically examined changes in FFM in response to high-intensity resistance training combined with dietary antioxidants in older men and women. The purpose of this study was to investigate whether 6 months of resistance training combined with antioxidant treatment could produce greater increases in FFM than one or no intervention.