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Francois Maltais - One of the best experts on this subject based on the ideXlab platform.
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in vitro and in vivo contractile properties of the Vastus Lateralis Muscle in males with copd
European Respiratory Journal, 2003Co-Authors: Richard Debigare, Pierre Leblanc, Claude H Cote, F S Hould, Francois MaltaisAbstract:Peripheral Muscle weakness is common in chronic obstructive pulmonary disease (COPD) but it is still under debate whether weakness is due to atrophy or contractile dysfunction. In vitro and in vivo contractile properties of the Vastus Lateralis Muscle were studied in 16 patients with stable COPD (forced expiratory volume in one second 39 +/- 16% of predicted, age 67 +/- 4 yrs (mean +/- sD)) and nine sedentary control subjects. Isometric knee extensor strength was measured while mid-thigh Muscle cross-sectional area (MTMCSA) was obtained using computed tomography. Muscle strips from the Vastus Lateralis obtained through open biopsy were rapidly suspended in an oxygenated Krebs-Ringer solution that was maintained at 35 degrees C with a pH of 7.40 to study their contractile properties. The isometric knee extensors strength/MTMCSA ratio was 0.50 +/- 0.08 versus 0.58 +/- 0.06 kg x cm(-2) for COPD and control subjects, respectively. The Muscle bundle cross-sectional area (CSA) was 4.6 +/- 2.1 and 4.4 +/- 3.1 mm(-2), the length at which active tension was maximum was 15 +/- 4 and 15 +/- 3 mm, and maximal isometric peak forces normalised for CSA were 4.3 +/- 2.7 and 4.8 +/- 2.6 N x cm(-2) for COPD and control subjects, respectively. The force/frequency relationship tended to be shifted to the right in patients with COPD, meaning that a higher stimulation frequency was necessary to produce the same relative force. Patients with COPD had a lower proportion of type I fibre than controls (26 +/- 12% versus 39 +/- 11%) with reciprocal significant increase in type IIb fibre proportion (20+/-16% versus 8 +/- 4%). The proportion of type IIa fibres was similar between the two groups. These results suggest that the contractile properties of the Vastus Lateralis are preserved in patients with chronic obstructive pulmonary disease. Therefore, the reduction in the quadriceps strength in patients with chronic obstructive pulmonary disease cannot be explained on the basis of an alteration of the contractile apparatus.
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in vitro and in vivo contractile properties of the Vastus Lateralis Muscle in males with copd
European Respiratory Journal, 2003Co-Authors: Richard Debigare, Pierre Leblanc, Claude H Cote, F S Hould, Francois MaltaisAbstract:Peripheral Muscle weakness is common in chronic obstructive pulmonary disease (COPD) but it is still under debate whether weakness is due to atrophy or contractile dysfunction. In vitro and in vivo contractile properties of the Vastus Lateralis Muscle were studied in 16 patients with stable COPD (forced expiratory volume in one second 39±16% of predicted, age 67±4 yrs (mean±sd)) and nine sedentary control subjects. Isometric knee extensor strength was measured while mid-thigh Muscle cross-sectional area (MTMCSA) was obtained using computed tomography. Muscle strips from the Vastus Lateralis obtained through open biopsy were rapidly suspended in an oxygenated Krebs-Ringer solution that was maintained at 35°C with a pH of 7.40 to study their contractile properties. The isometric knee extensors strength/MTMCSA ratio was 0.50±0.08 versus 0.58±0.06 kg·cm −2 for COPD and control subjects, respectively. The Muscle bundle cross-sectional area (CSA) was 4.6±2.1 and 4.4±3.1 mm −2 , the length at which active tension was maximum was 15±4 and 15±3 mm, and maximal isometric peak forces normalised for CSA were 4.3±2.7 and 4.8±2.6 N·cm −2 for COPD and control subjects, respectively. The force/frequency relationship tended to be shifted to the right in patients with COPD, meaning that a higher stimulation frequency was necessary to produce the same relative force. Patients with COPD had a lower proportion of type I fibre than controls (26±12% versus 39±11%) with reciprocal significant increase in type IIb fibre proportion (20±16% versus 8±4%). The proportion of type IIa fibres was similar between the two groups. These results suggest that the contractile properties of the Vastus Lateralis are preserved in patients with chronic obstructive pulmonary disease. Therefore, the reduction in the quadriceps strength in patients with chronic obstructive pulmonary disease cannot be explained on the basis of an alteration of the contractile apparatus.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (VO(2)) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (& pVO2) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002 DOI 10.1002/mus.10039
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
Jean Jobin - One of the best experts on this subject based on the ideXlab platform.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (VO(2)) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (& pVO2) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002 DOI 10.1002/mus.10039
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
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altered expression of myosin heavy chain in the Vastus Lateralis Muscle in patients with copd
European Respiratory Journal, 1999Co-Authors: Francois Maltais, Pierre Leblanc, C Simard, Martin J Sullivan, Brian D Duscha, Fred Schachat, Jason M Blank, Jean JobinAbstract:This study was designed to further characterize peripheral skeletal Muscle alterations in patients with chronic obstructive pulmonary disease (COPD) and to evaluate the possible relationship between myosin heavy chain (MyoHC) isoform expression and exercise tolerance in these individuals. MyoHC composition from biopsy of the Vastus Lateralis Muscle was examined in 12 COPD patients (forced expiratory volume in one second (FEV1)=31+/-9% predicted, peak oxygen consumption (V'O2)=15+/-4 mL x kg(-1) x min(-1)) and 10 age-matched normal male subjects (peak V'O2=20+/-5 mL x kg(-1) x min(-1)). The proportion of MyoHC type I was smaller in COPD than in normals (27+/-17% versus 41+/-9%, p<0.05) with an increase in MyoHC type IIa (51+/-15% versus 39+/-9%, p<0.05) and the proportion of MyoHC type IIx being comparable between both groups. A significant relationship was found between peak V'Oo2 mL x kg(-1) x min(-1) and FEV1 % pred (r=0.91, p<0.0001) and the percentage of MyoHC type I (r=0.61, p=0.016). In stepwise multiple regression, only FEV1 % pred was found to be a significant determinant of peak V'O2 (p<0.0001). This variable explained 83% of the total variance of peak V'O2. In summary, this study showed considerable modifications in the phenotypic expression of the myosin heavy chain in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease. An independent effect of myosin heavy chain expression on exercise capacity was not found. These results suggest that chronic inactivity and Muscle deconditioning may not be the sole factors explaining peripheral Muscle dysfunction in patients with chronic obstructive pulmonary disease.
Pierre Leblanc - One of the best experts on this subject based on the ideXlab platform.
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in vitro and in vivo contractile properties of the Vastus Lateralis Muscle in males with copd
European Respiratory Journal, 2003Co-Authors: Richard Debigare, Pierre Leblanc, Claude H Cote, F S Hould, Francois MaltaisAbstract:Peripheral Muscle weakness is common in chronic obstructive pulmonary disease (COPD) but it is still under debate whether weakness is due to atrophy or contractile dysfunction. In vitro and in vivo contractile properties of the Vastus Lateralis Muscle were studied in 16 patients with stable COPD (forced expiratory volume in one second 39 +/- 16% of predicted, age 67 +/- 4 yrs (mean +/- sD)) and nine sedentary control subjects. Isometric knee extensor strength was measured while mid-thigh Muscle cross-sectional area (MTMCSA) was obtained using computed tomography. Muscle strips from the Vastus Lateralis obtained through open biopsy were rapidly suspended in an oxygenated Krebs-Ringer solution that was maintained at 35 degrees C with a pH of 7.40 to study their contractile properties. The isometric knee extensors strength/MTMCSA ratio was 0.50 +/- 0.08 versus 0.58 +/- 0.06 kg x cm(-2) for COPD and control subjects, respectively. The Muscle bundle cross-sectional area (CSA) was 4.6 +/- 2.1 and 4.4 +/- 3.1 mm(-2), the length at which active tension was maximum was 15 +/- 4 and 15 +/- 3 mm, and maximal isometric peak forces normalised for CSA were 4.3 +/- 2.7 and 4.8 +/- 2.6 N x cm(-2) for COPD and control subjects, respectively. The force/frequency relationship tended to be shifted to the right in patients with COPD, meaning that a higher stimulation frequency was necessary to produce the same relative force. Patients with COPD had a lower proportion of type I fibre than controls (26 +/- 12% versus 39 +/- 11%) with reciprocal significant increase in type IIb fibre proportion (20+/-16% versus 8 +/- 4%). The proportion of type IIa fibres was similar between the two groups. These results suggest that the contractile properties of the Vastus Lateralis are preserved in patients with chronic obstructive pulmonary disease. Therefore, the reduction in the quadriceps strength in patients with chronic obstructive pulmonary disease cannot be explained on the basis of an alteration of the contractile apparatus.
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in vitro and in vivo contractile properties of the Vastus Lateralis Muscle in males with copd
European Respiratory Journal, 2003Co-Authors: Richard Debigare, Pierre Leblanc, Claude H Cote, F S Hould, Francois MaltaisAbstract:Peripheral Muscle weakness is common in chronic obstructive pulmonary disease (COPD) but it is still under debate whether weakness is due to atrophy or contractile dysfunction. In vitro and in vivo contractile properties of the Vastus Lateralis Muscle were studied in 16 patients with stable COPD (forced expiratory volume in one second 39±16% of predicted, age 67±4 yrs (mean±sd)) and nine sedentary control subjects. Isometric knee extensor strength was measured while mid-thigh Muscle cross-sectional area (MTMCSA) was obtained using computed tomography. Muscle strips from the Vastus Lateralis obtained through open biopsy were rapidly suspended in an oxygenated Krebs-Ringer solution that was maintained at 35°C with a pH of 7.40 to study their contractile properties. The isometric knee extensors strength/MTMCSA ratio was 0.50±0.08 versus 0.58±0.06 kg·cm −2 for COPD and control subjects, respectively. The Muscle bundle cross-sectional area (CSA) was 4.6±2.1 and 4.4±3.1 mm −2 , the length at which active tension was maximum was 15±4 and 15±3 mm, and maximal isometric peak forces normalised for CSA were 4.3±2.7 and 4.8±2.6 N·cm −2 for COPD and control subjects, respectively. The force/frequency relationship tended to be shifted to the right in patients with COPD, meaning that a higher stimulation frequency was necessary to produce the same relative force. Patients with COPD had a lower proportion of type I fibre than controls (26±12% versus 39±11%) with reciprocal significant increase in type IIb fibre proportion (20±16% versus 8±4%). The proportion of type IIa fibres was similar between the two groups. These results suggest that the contractile properties of the Vastus Lateralis are preserved in patients with chronic obstructive pulmonary disease. Therefore, the reduction in the quadriceps strength in patients with chronic obstructive pulmonary disease cannot be explained on the basis of an alteration of the contractile apparatus.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (VO(2)) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (& pVO2) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002 DOI 10.1002/mus.10039
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
M Chinlin D Chen - One of the best experts on this subject based on the ideXlab platform.
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a free composite de epithelialized anterolateral thigh and the Vastus Lateralis Muscle flap for the reconstruction of a large defect of the anterior skull base a case report
Microsurgery, 2011Co-Authors: M Kuochuan D Lo, M Chuhsu D Jeng, M Chenghan D Hsieh, M Chinlin D ChenAbstract:Reconstruction of the anterior skull base is one of the greatest challenges for reconstructive surgeons. Sometimes, the defect is so large that a local flap is insufficient for the reconstruction. In this report, we present a case of malignant meningioma of the anterior skull base. The tumor was treated by surgical excision resulting in a large defect from the anterior skull base to the nasal cavity. The entire defect was within the cranial vault. The reconstruction was achieved using a free composite de-epithelialized anterolateral thigh and the Vastus Lateralis Muscle flap. Postoperative monitoring included hand Doppler and daily endoscopic inspection. This patient was satisfied with the cosmetic result. After 10 months, magnetic resonance imaging (MRI), performed to assess the flap, demonstrated that the volume of the de-epithelialized skin paddle of the anterolateral thigh flap had not changed, and that there was no tissue atrophy between the patient's eyes that could have resulted in deformity. © 2011 Wiley-Liss, Inc. Microsurgery, 2011.
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a free composite de epithelialized anterolateral thigh and the Vastus Lateralis Muscle flap for the reconstruction of a large defect of the anterior skull base a case report
Microsurgery, 2011Co-Authors: M Chuhsu D Jeng, M Chenghan D Hsieh, M Hwangchi D Lin, M Chinlin D ChenAbstract:Reconstruction of the anterior skull base is one of the greatest challenges for reconstructive surgeons. Sometimes, the defect is so large that a local flap is insufficient for the reconstruction. In this report, we present a case of malignant meningioma of the anterior skull base. The tumor was treated by surgical excision resulting in a large defect from the anterior skull base to the nasal cavity. The entire defect was within the cranial vault. The reconstruction was achieved using a free composite de-epithelialized anterolateral thigh and the Vastus Lateralis Muscle flap. Postoperative monitoring included hand Doppler and daily endoscopic inspection. This patient was satisfied with the cosmetic result. After 10 months, magnetic resonance imaging (MRI), performed to assess the flap, demonstrated that the volume of the de-epithelialized skin paddle of the anterolateral thigh flap had not changed, and that there was no tissue atrophy between the patient's eyes that could have resulted in deformity.
C Simard - One of the best experts on this subject based on the ideXlab platform.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (VO(2)) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD.
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lipofuscin accumulation in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease
Muscle & Nerve, 2002Co-Authors: Joakim Allaire, Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, P M Simard, Jeanfrancois Doyon, Jean JobinAbstract:Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in Muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting Muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the Vastus Lateralis Muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (& pVO2) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the Vastus Lateralis Muscle in patients with COPD compared to healthy subjects. Oxidative damage of Muscle tissue may thus be involved in skeletal Muscle dysfunction and wasting in COPD. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002 DOI 10.1002/mus.10039
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
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oxidative enzyme activities of the Vastus Lateralis Muscle and the functional status in patients with copd
Thorax, 2000Co-Authors: Francois Maltais, Pierre Leblanc, Francois Whittom, C Simard, Karine Marquis, Marthe Belanger, Mariejosee Breton, Jean JobinAbstract:BACKGROUND Enzymatic and histochemical abnormalities of the peripheral Muscle may play a role in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). A study was undertaken to measure the mitochondrial enzyme activity of the Vastus Lateralis Muscle in patients with COPD and to evaluate the relationship between enzyme activities and functional status. METHODS Fifty seven patients with COPD of mean (SD) age 66 (7) years with forced expiratory volume in one second (FEV1) 39 (15)% predicted and peak oxygen uptake (V˙o 2) of 14 (4) ml/min/kg and 15 normal subjects of similar age were included in the study. Each subject performed a stepwise exercise test up to maximal capacity during which five-breath averages of V˙o 2were measured. Muscle specimens were obtained by percutaneous needle biopsy of the Vastus Lateralis Muscle and the activity of two mitochondrial enzymes (citrate synthase (CS) and 3-hydroxyacyl CoA dehydrogenase (HADH)) was measured. The functional status of the patients was classified according to peakV˙o 2. RESULTS CS and HADH activities were markedly reduced in patients with COPD compared with normal subjects (22.3 (2.7) versus 29.5 (7.3) μmol/min/g Muscle (p<0.0001) and 5.1 (2.0) versus 6.7 (1.9) μmol/min/g Muscle (p<0.005), respectively). The activity of CS decreased progressively with the deterioration in the functional status while that of HADH was not related to functional status. Using a stepwise regression analysis, percentage predicted functional residual capacity (FRC), the activity of CS, oxygen desaturation during exercise, age, and inspiratory capacity (% pred) were found to be significant determinants of peakV˙o 2. The regression model explained 59% of the variance in peak V˙o 2 (p<0.0001). CONCLUSIONS The oxidative capacity of the Vastus Lateralis Muscle is reduced in patients with moderate to severe COPD compared with normal subjects of similar age. In these individuals the activity of CS correlated significantly with peak exercise capacity and independently of lung function impairment.
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altered expression of myosin heavy chain in the Vastus Lateralis Muscle in patients with copd
European Respiratory Journal, 1999Co-Authors: Francois Maltais, Pierre Leblanc, C Simard, Martin J Sullivan, Brian D Duscha, Fred Schachat, Jason M Blank, Jean JobinAbstract:This study was designed to further characterize peripheral skeletal Muscle alterations in patients with chronic obstructive pulmonary disease (COPD) and to evaluate the possible relationship between myosin heavy chain (MyoHC) isoform expression and exercise tolerance in these individuals. MyoHC composition from biopsy of the Vastus Lateralis Muscle was examined in 12 COPD patients (forced expiratory volume in one second (FEV1)=31+/-9% predicted, peak oxygen consumption (V'O2)=15+/-4 mL x kg(-1) x min(-1)) and 10 age-matched normal male subjects (peak V'O2=20+/-5 mL x kg(-1) x min(-1)). The proportion of MyoHC type I was smaller in COPD than in normals (27+/-17% versus 41+/-9%, p<0.05) with an increase in MyoHC type IIa (51+/-15% versus 39+/-9%, p<0.05) and the proportion of MyoHC type IIx being comparable between both groups. A significant relationship was found between peak V'Oo2 mL x kg(-1) x min(-1) and FEV1 % pred (r=0.91, p<0.0001) and the percentage of MyoHC type I (r=0.61, p=0.016). In stepwise multiple regression, only FEV1 % pred was found to be a significant determinant of peak V'O2 (p<0.0001). This variable explained 83% of the total variance of peak V'O2. In summary, this study showed considerable modifications in the phenotypic expression of the myosin heavy chain in the Vastus Lateralis Muscle in patients with chronic obstructive pulmonary disease. An independent effect of myosin heavy chain expression on exercise capacity was not found. These results suggest that chronic inactivity and Muscle deconditioning may not be the sole factors explaining peripheral Muscle dysfunction in patients with chronic obstructive pulmonary disease.
