Charles Lambert - Academia.edu (original) (raw)

Papers by Charles Lambert

Administration of the hepatotoxin and carcinogen, inorganic hydrazine, to rodents results in the ... more Administration of the hepatotoxin and carcinogen, inorganic hydrazine, to rodents results in the formation of 7-methylguanine and O6-methylguanine in liver DNA; co-administration of [methyl-14C]methionine or [14C]formate with the hydrazine labels the methylguanines, suggesting involvement of the 1-carbon pool in the methylation process. The present study investigates the proposal that the methylation mechanism involves reaction of hydrazine with endogenous formaldehyde to yield formaldehyde hydrazone, which could be metabolized to the potent methylating agent diazomethane. Hamsters were pretreated with methanol, ethanol or cyanamide to alter the endogenous hepatic aldehyde levels prior to administration of hydrazine. Formaldehyde levels were refractory to the pretreatments; hepatic acetaldehyde levels were increased, but hydrazine administration under such conditions did not result in the formation of ethylated guanines in DNA. Methanol and ethanol inhibited hydrazine-induced methylation of DNA. Hydrazine incubated with liver S9 fraction and calf thymus DNA induced the formation of 7-methylguanine and O6-methylguanine when formaldehyde was present in the incubation system; substitution of formaldehyde with acetaldehyde in the incubation medium did not result in any detectable alkylation of DNA. Both liver microsomal and cytosolic fractions demonstrated heat-labile activity in supporting the hydrazine-induced methylation process. Tetraformyltrisazine, or a similar reaction product of hydrazine and formaldehyde, may be a more important intermediate than formaldehyde hydrazone in the hydrazine-induced methylation of DNA.

Medicine Amp Science in Sports Amp Exercise, May 31, 2003

Purpose: We examined the influence of ibuprofen and acetaminophen on muscle neutrophil and macrop... more Purpose: We examined the influence of ibuprofen and acetaminophen on muscle neutrophil and macrophage concentrations after novel eccentric contractions. Methods: Twenty-four males (25 Ϯ 3 yr) were divided into three groups that received the maximal over-the-counter dose of either ibuprofen (1200 mg·d Ϫ1 ), acetaminophen (4000 mg·d Ϫ1 ), or a placebo after eccentric contractions of the knee extensors. Biopsies from the vastus lateralis were taken before and 24 h after exercise. Inflammatory cells were quantified in muscle cross-sections using immunohistochemistry. Results: Macrophage concentrations were elevated by 1.5-to 2.5-fold (P Ͻ 0.05) at 24 h postexercise relative to preexercise concentrations, whereas neutrophil concentrations were not significantly elevated. Muscle inflammatory cell concentrations were unaffected by treatment with ibuprofen or acetaminophen when compared with placebo. Conclusions: Maximal over-the-counter doses of ibuprofen or acetaminophen, when administered therapeutically, do not affect muscle concentrations of neutrophils or macrophages 24 h after a novel bout of eccentric contractions.

Mol Reprod Dev, 2000

The solitary ascidians Ciona intestinalis and Ciona savignyi co-occur in southern California harb... more The solitary ascidians Ciona intestinalis and Ciona savignyi co-occur in southern California harbors, but no hybrids have been recognized in nature. Numerous differences in their egg morphology were detected. Homologous (normal outcross) fertilization yielded 96-99% cleavage, where autologous (self) fertilization showed 3% and heterologous (hybrid) fertilization showed 0-1%. Acid treatment (pH 3.2) removed the block to selfing (P Ͻ 0.0001) but not hybridization for both species. Heterologous sperm bind to the vitelline coat (VC), but fail to penetrate. Enzymatic removal of the VC resulted in 91-97% cleavage with autologous and heterologous sperm (P Ͻ 0.0001). The vitelline coats of the two species differ in lectin binding to surface glycosides. Fertilization in both species is significantly inhibited by the lectins, fucose binding protein (P Ͻ 0.0001) and concanavalin A (P Ͻ 0.0001), and wheat germ agglutinin inhibits fertilization in C. intestinalis (P Ͻ 0.0001) but is without effect on C. savignyi fertilization. Self and hybrid blocks employ different mechanisms including glycoside composition and acid sensitivity. Mol. Reprod. Dev. 55:109-116, 2000.

American Journal of Physical Medicine Rehabilitation, Feb 1, 2007

Evans WJ, Lambert CP: Physiological basis of fatigue. Am J Phys Med Rehabil 2007;86(Suppl):S29 -S46.

The Journal of Sports Medicine and Physical Fitness, Dec 1, 1999

To determine energy intake in the 2 hrs after swimming (S) and running (R) at the same relative e... more To determine energy intake in the 2 hrs after swimming (S) and running (R) at the same relative exercise intensity and duration (71.8 +/- 2.5% VO2max; 45 min) to evaluate whether a difference in recovery energy intake could explain the greater body fat observed in swimmers relative to runners. this was a randomized crossover design. running exercise was conducted on a motorized treadmill (Quinton) while swimming was conducted in a 45.7 m pool. eight well-trained competitive male triathletes participated in this investigation. subjects were blinded to the purpose of the study and swam and ran on separate occasions for 45 min at 71.8 +/- 2.5% of VO2max. Subjects were then placed in a room with a variety of foods and beverages for 2 hrs after R and S. energy intake (kJ/2 hrs and kcal/2 hrs) was determined by weighing and measuring the food remaining in the room after 2 hrs of postexercise recovery. Expired gases, heart rates, and Ratings of Perceived Exertion were obtained at 15 min intervals throughout exercise. Blood samples for serum glucose and lactate were obtained preexercise and immediately, 15 min, and 135 min postexercise. Perceived hunger and thirst ratings were obtained after the subjects were seated in the room containing the food. Serum glucose was significantly (p &amp;lt; or = 0.05) higher after R compared to S immediately after exercise (5.4 +/- 0.3 mmol/L for R and 4.2 +/- 0.1 mmol/L for S) but no significant differences were observed for hunger using a five point Likert scale (3.3 +/- 0.3 for R and 3.4 +/- 0.3 for S), energy intake (4584 +/- 611 kJ/2 hrs; 1095 +/- 146 kcal/2 hrs for R and 4383 +/- 484 kJ/2 hrs; 1047 +/- 116 kcal for S) or blood lactate. The type of exercise, swimming or running, did not significantly influence energy intake during 2 hours of postexercise recovery.

We examined the effect of two commonly consumed over-the-counter analgesics, ibuprofen and acetam... more We examined the effect of two commonly consumed over-the-counter analgesics, ibuprofen and acetaminophen, on muscle protein synthesis and soreness following high intensity eccentric resistance exercise. Twenty four males (25 ±3 y, 180 ±6 cm, 81 ±6 kg, and 17 ±8 % body fat) were assigned to one of three groups that received either the maximal over-the-counter dose of ibuprofen (IBU; 1200 mg•d -1 ), acetaminophen (ACET; 4000 mg•d -1 ), or a placebo (PLA) following 10-14 sets of 10 eccentric repetitions at 120% of concentric 1 repetition maximum using the knee extensors. Post-exercise (24 h) skeletal muscle fractional synthesis rate (FSR) was increased 76 ±19% (p<0.05) in PLA (0.058 ±0.012 %•h -1 ), and was unchanged (p>0.05) in IBU (35 ±21%; 0.021 ±0.014 %•h -1 ) and ACET (22 ±23%; 0.010 ±0.019 %•h -1 ). Neither drug had any influence on whole body protein breakdown, as measured by rate of phenylalanine appearance, on serum creatine kinase, or on rating of perceived muscle soreness compared with PLA. These results suggest that over-the-counter doses of both ibuprofen and acetaminophen suppress the protein synthesis response in skeletal muscle following eccentric resistance exercise.

Coronary Artery Dis, 1994

Local drug delivery is a potential solution to postintervention restenosis. Most catheters develo... more Local drug delivery is a potential solution to postintervention restenosis. Most catheters developed for local delivery depend upon control of pressure and of delivered volume for optimal performance. The present study was designed to assess the accuracy of current methods for inflation of local delivery catheters compared with a new microprocessor-controlled system specifically designed for this application. An in vitro gravimetric testing system was constructed to record developed pressure and delivered volume using a variety of inflation devices and a microporous infusion catheter. Experienced catheterization laboratory personnel were given commercial angioplasty indeflators and a pressure-driven syringe and asked to quickly apply 5 atm and deliver 2.0 ml. A new microprocessor-controlled system was then tested using the same protocol. The time required to reach a plateau pressure was lowest with the pressure-driven syringe (0.164 +/- 0.017 s) and much higher with standard indeflators (2.94 +/- 2.54, 4.64 +/- 2.98, 7.69 +/- 4.89, 8.28 +/- 6.31 s). The corresponding microprocessor-controlled value was much lower than that of the manual systems (0.84 +/- 0.37 s). The variability of plateau pressure, as measured by the standard deviation, was lowest with the pressure-driven syringe (0.029 +/- 0.014 atm) and highest with the manual systems (0.37 +/- 0.26, 0.40 +/- 0.18, 0.44 +/- 0.31, 0.32 +/- 0.10 atm). The microprocessor-controlled system also produced very little variability in pressure (0.08 +/- 0.004 atm). The volume delivered varied significantly with all manual devices (1.77 +/- 0.64, 1.74 +/- 0.66, 1.36 +/- 0.45, 1.80 +/- 0.33 ml) as well as with the pressure-driven syringe (1.86 +/- 0.32 ml), but the volume delivered by the microprocessor-controlled system was highly accurate (1.99 +/- 0.06 ml). Manual inflation devices do not allow precise control of pressure or volume when used with local delivery catheters. Use of a pressure-driven syringe minimizes pressure error, but does not deliver an accurate volume. The microprocessor-controlled system minimizes pressure and volume error and should maximize transfer efficiency for local delivery catheter systems.

Medicine Amp Science in Sports Amp Exercise, Oct 1, 2001

To compare muscle strength and muscle fatigue of the knee extensors and flexors in individuals wi... more To compare muscle strength and muscle fatigue of the knee extensors and flexors in individuals with multiple sclerosis (MS) and non-MS control subjects and to evaluate the reliability of muscle strength and muscle fatigue testing in these individuals. Thirty individuals (13 women and 2 men for both MS and control groups), age (mean +/- SD) 38.8 +/- 10 for MS and 33.1 +/- 7.6 yr for controls, participated in this investigation. Peak torque was measured on two occasions separated by approximately 7 d at 30, 60, 90, 120, 180 degrees.s(-1) with 2 min of recovery between each bout. The nondominant leg was tested followed by the dominant leg after 10 min of recovery. Subjects then performed three bouts of 30 flexions and extensions of the dominant leg at 180 degrees.s(-1) with 1 min of recovery between bouts. The reliability of muscle torque was very high for individuals with MS (only 1 of 20 measurements with an ICC below 0.900). Total work was also highly reliable for MS, but the Fatigue Index (work during the last 15 contractions/work during the first 15 contractions) x 100 was not. Peak torque adjusted for age, body mass, and fat free mass (measured by whole body plethysmography; the Bod Pod; Life Measurement Instruments; Concord, CA) was significantly greater for controls than for MS for three of four lower body muscle groups tested. For the muscle fatigue test (3 bouts of 30 knee extensions and flexions at 180 degrees.s(-1)), the Fatigue Index was greater (less fatigue) for the knee extensors for controls than MS for the third bout. For flexion, the Fatigue Index was greater for controls than MS over the three bouts (group effect). Total work was significantly greater for controls than MS for the flexors (group effect) and approached significance for the extensors. Individuals with MS were weaker than controls when data were adjusted for age, body mass, and fat free mass. This latter finding (force relative to age and fat free mass) suggests that there is a reduced ability to activate muscle mass in MS and/or the muscle mass of individuals with MS is of lower quality (i.e., reduced force/unit muscle mass) than controls.

European Journal of Applied Physiology, May 1, 2000

J Clin Endocrinol Metab, 2001

PGs have been shown to modulate skeletal muscle protein metabolism as well as inflammation and pa... more PGs have been shown to modulate skeletal muscle protein metabolism as well as inflammation and pain. In nonskeletal muscle tissues, the over the counter analgesic drugs ibuprofen and acetaminophen function through suppression of PG synthesis. We previously reported that ibuprofen and acetaminophen inhibit the normal increase in skeletal muscle protein synthesis after high intensity eccentric resistance exercise. The current study examined skeletal muscle PG levels in the same subjects to further investigate the mechanisms of action of these drugs in exercised skeletal muscle. Twentyfour males (25 ؎ 3 yr) were assigned to 3 groups that received the maximal over the counter dose of ibuprofen (1200 mg/d), acetaminophen (4000 mg/d), or a placebo after 10 -14 sets of 10 eccentric repetitions at 120% of concentric 1 repetition maximum using the knee extensors. Preexercise and 24 h postex-ercise biopsies of the vastus lateralis revealed that the exercise-induced change in PGF 2␣ in the placebo group (77%) was significantly different (P < 0.05) from those in the ibuprofen (؊1%) and acetaminophen (؊14%) groups. However, the exercise-induced change in PGE 2 in the placebo group (64%) was only significantly different (P < 0.05) from that in the acetaminophen group (؊16%). The exercise-induced changes in PGF 2␣ and PGE 2 were not different between the ibuprofen and acetaminophen groups. These results suggest that ibuprofen and acetaminophen have a comparable effect on suppressing the normal increase in PGF 2␣ in human skeletal muscle after eccentric resistance exercise, which may profoundly influence the anabolic response of muscle to this form of exercise. (J Clin Endocrinol Metab 86: 5067-5070, 2001)

Publice Premium, Jun 5, 2007

The Journal of Strength and Conditioning Research, Oct 31, 1991

ABSTRACT Seven experienced resistance athletes were studied to evaluate the influence of glucose ... more ABSTRACT Seven experienced resistance athletes were studied to evaluate the influence of glucose polymer ingestion on performance during a resistance training workout. Each subject participated in two randomly assigned trials separated by at least one week. On one occasion the subjects ingested a 10 percent glucose polymer solution (GP) (one gram CHO per kilogram of body weight) immediately before exercise, while on another occasion a similarly colored and flavored placebo (P) was ingested. The subjects then performed leg extensions (Nautilus Inc., Deland, Florida) at 80 percent of their previously determined 10-repetition maximums (10 RM), with three minutes of rest between sets. Subjects performed 10 repetitions on the first set and continued until they failed to perform seven repetitions for a set (fatigue). Additional GP (0.17 gram CHO per kilogram of body weight) or P solutions were given after the fifth, 10th and 15th sets. Venous forearm blood samples were taken before exercise, after the seventh set and at the point of fatigue, and were analyzed for glucose and lactate. Blood glucose was significantly higher (p < 0.05) in the GP treatment after the seventh set and at fatigue (10.00 +/- 1.00 mM and 8.44 +/- 0.70 mM, respectively) compared to the P treatment (6.90 +/- 0.25 mM and 6.13 +/- 0.24 mM, respectively). Blood lactate was significantly higher for the GP treatment after the seventh set compared to the P treatment (7.10 +/- 0.31 mM for GP and 5.57 0.19 mM for P). Performance measured in number of sets (17.1 +/- 2.0 for GP and 14.4 +/- 1.7 for P) and repetitions (149 +/- 16 for GP and 129 +/- 12 for P) was greater for GP than for P, and these differences approached but did not achieve statistical significance (p = 0.067 for sets and p = 0.056 for repetitions). The results suggest that glucose polymer ingestion elevates glucose and lactate in the blood and tends to improve performance during multiple-bout (approximately 15 sets) resistance exercise. (C) 1991 National Strength and Conditioning Association

Development Growth Differentiation, 1994

During fertilization or ionophore induced activation, ascidian eggs rapidly release cell surface ... more During fertilization or ionophore induced activation, ascidian eggs rapidly release cell surface N-acetylglucosaminidase activity used in the block against polyspermy and undergo cortical contractions before they re-initiate meiosis. To better understand the activation process, we probed the relationship between these two processes in Ascidia cerafodes eggs by activating with different agents that increase intracellular Ca levels and under different ionic conditions. Glycosidase activity release was followed by the use of a fluorogenic substrate, and cortical contractions were followed by examining changes in cell shape with light microscopy. lonomycin (2.7 pM) and thimerosal (1 mM) initiate glycosidase release and cortical contractions when administered in complete sea water (SW) but only the contractions in low Ca SW. Ryanodine (0.67 mM), known to raise free intracellular Ca in a number of cell types by release from the endoplasrnic reticulum, causes glycosidase release but fails to initiate cortical contractions in complete SW. Thapsigargin (lOpM), which inhibits Ca dependent ATPase in the ER, causes glycosidase release but induces the contractions only about 50% of the time. These experiments show that, although glycosidase release normally precedes the ooplasrnic shape changes that accompany the resumption of meiosis in ascidian eggs, they are not obligately coupled. That both processes can be induced by treatments known to raise intracellular Ca in other systems but under different conditions indicates that there may be a multiplicity of Ca requiring but functionally independent events during egg activation.

The Journal of Strength and Conditioning Research, Apr 30, 1995

ABSTRACT This study compared the physiological, perceptual, and metabolic responses of peak and m... more ABSTRACT This study compared the physiological, perceptual, and metabolic responses of peak and moderate intensity deep-water running and treadmill running. Eight well-trained male runners performed peak deep-water and treadmill running tests and participated in three 15-min steady-state submaximal exercise trials; (a) treadmill running at 75% of treadmill running [latin capital V with dot above]02peak, (b) deep-water running at an estimated 75% (actual approx. 70%) of deep-water running [latin capital V with dot above]O2,peak, and (c) deep-water running at 75% of treadmill running [latin capital V with dot above]02peak. Peak oxygen consumption and heart rate were significantly greater (p < 0.05) for treadmill running. At similar relative and absolute exercise intensities, blood lactate and respiratory exchange ratio were significantly greater during deep-water running. At the same absolute exercise intensity, rating of perceived exertion was also significantly greater during deep-water running. Although at a similar relative exercise intensity treadmill running [latin capital V with dot above]O2, was significantly greater than deep-water running, no significant differences were found for heart rate between trials. Thus it appears there are differences in exercise responses between peak as well as moderate intensity deep-water and treadmill running. (C) 1995 National Strength and Conditioning Association

The New Zealand solitary ascidian Pyura pachydermatina (Phylum Chordata, Subphylum Urochordata) i... more The New Zealand solitary ascidian Pyura pachydermatina (Phylum Chordata, Subphylum Urochordata) is a sessile filter feeder in rocky wave-swept coastal areas. The body is on a long stalk; both are covered by a tough fibrous tunic. Two types of spicules are formed in vascularized areas: "antler-shaped" branched spicules of amorphous calcium carbonate in blood sinuses in the body tissues and "dogbone-shaped" knobbed calcitic spicules in the tunic blood vessels. Both types form extracellularly, contain intraspicular organic components and are covered by an organic matrix coat within an epithelium of sclerocytes. SEM and TEM analysis of the spicules and their formation is included, along with calcein incorporation data used to estimate rate of growth. A comparison with spicules of other ascidians and in selected other organisms is included, with comments on the shared features of biomineralization that these disparate groups exhibit.

Coronary Artery Disease, May 1, 1993

The porous (Wolinski) balloon was designed to allow local delivery of compounds targeted to inhib... more The porous (Wolinski) balloon was designed to allow local delivery of compounds targeted to inhibit postintervention restenosis; however, successful use of the device has been hampered by arterial trauma caused by the balloon itself. This study utilized several experimental systems to assess the functional characteristics of the porous balloon catheter. This information was utilized to design and test a new microporous infusion catheter for local intra-arterial drug delivery. Flow characteristics in fluid and semisolid media as well as arterial trauma by light and electron microscopy were documented for the porous and microporous balloons. In addition, the efficacy of methylene blue delivery in situ and in vitro was documented and quantified for the microporous design. The porous balloon exhibits flow characteristics consistent with orifice-related streaming that produces arterial trauma. By maximizing external balloon-pore density and minimizing pore size, the microporous design minimizes streaming in test systems. This is manifested by minimal arterial trauma when applied to intact arteries. The microporous catheter is effective for dye delivery both in situ and in vivo. The microporous catheter design offers improved functional characteristics when compared with the porous balloon for local intra-arterial drug delivery.