alfredo cordova - Academia.edu (original) (raw)

Papers by alfredo cordova

Apunts Medicina De L Esport, 2010

Rebut el 17 de maig de 2010; acceptat el 10 de juny de 2010

J Surg Res, 2006

lular gap formation and increased permeability in endothelial monolayer. We hypothesize that the ... more lular gap formation and increased permeability in endothelial monolayer. We hypothesize that the three tyrosine residue(s) in the C terminus of VE cadherin (Y784, 774, and 757) are important for cadherin phosphorylation and cadherin-catenin dissociation. Methods: Human umbilical vein endothelial cells, HUVEC, were infected with adenoviral constructs containing either full length VE cadherin-GFP fusion protein (AdVEC-GFP), or C terminal truncated VE cadherin-GFP fusion protein (AdVEC-756), and then exposed to vehicle or VEGF (50ng/ml). VE cadherin was immunoprecipitated with GFP antibody and immunoblotted with anti-phosphotyrosine. Results: VEGF exposure caused phosphorylation of the full length VE cadherin-GFP fusion protein but failed to induce phosphorylation of the truncated construct. Conclusion: We conclude that one or more of the three tyrosine residues in the C terminus of VE cadherin regulate VEGF-induced VE cadherin phosphorylation and endothelial cell signaling.

Acta Zoologica Mexicana, 2000

Free Radical Research, Sep 1, 2007

We studied the effects of intense exercise on the neutrophil antioxidant enzyme activities and ge... more We studied the effects of intense exercise on the neutrophil antioxidant enzyme activities and gene expression. Blood samples were taken from seven cyclists in basal conditions and 3 h after two competition stages of 165 km. Serum creatine kinase (CK) activity, plasma carbonyl derivatives and uric acid levels increased after exercise. The cycling stage induced neutrophilia and increased myeloperoxidase (MPO) activity and reactive oxygen species (ROS) production. Antioxidant enzyme activities (catalase, glutathione peroxidase and superoxide dismutase) decreased after exercise, although gene expression increased. Immunocytochemistry showed catalase (CAT) enzyme equally distributed between the cytoplasm and organelles before exercise, and after exercise the cytoplasmic CAT levels were reduced and were absent in the compartments. After in vitro stimulation with opsonized zymosan (OZ) the extracellular CAT levels increased. This suggests a CAT secretion in order to avoid neutrophil-induced oxidative damage at a local level or to regulate the function of ROS as extracellular signalling molecules.

Membrane type 1-matrix metalloproteinase (MT1-MMP) plays a key role in extracellular matrix remod... more Membrane type 1-matrix metalloproteinase (MT1-MMP) plays a key role in extracellular matrix remodeling, endothelial cell (EC) migration, and angiogenesis. Whereas cyclic strain (CS) increases MT1-MMP expression, shear stress (SS) decreases MT1-MMP expression. The aim of this study was to determine if changes in levels of Sp1 phosphorylation induced by protein kinase Czeta (PKCzeta) in ECs exposed to SS but not CS are important for MT1-MMP expression. The results showed that SS increased Sp1 phosphorylation, which could be inhibited by pretreatment with PKCzeta inhibitors. In the presence of PKCzeta inhibitors, the SS-mediated decrease in MT1-MMP protein expression was also abolished. These data demonstrate that increased affinity of Sp1 for MT1-MMP's promoter site occurs as a consequence of PKCzeta-induced phosphorylation of Sp1 in response to SS, increasing Sp1 binding affinity for the promoter site, preventing Egr-1 binding, and consequently decreasing MT1-MMP expression.

Journal of Sports Science Medicine, May 1, 2014

The aim of this study was to compare the physiological responses of cyclists using round (C-ring)... more The aim of this study was to compare the physiological responses of cyclists using round (C-ring) or oval (Q-ring) chainrings during an incremental test until exhaustion. Following a randomized design, twelve male elite cyclists [age (mean ± SD): 21.1 ± 2.1 yr; VO2max: 78.1 ± 5.3 mL·kg(-1)min(-1)] performed two incremental maximal tests separated by 48 h (one with C-rings, the other with Q-rings). Starting at 100 W, the workload was increased by 25 W every 3 min until volitional exhaustion. Maximal heart rate, power output and oxygen consumption were compared. Blood lactate was monitored throughout the test. After the incremental test, 4 intermittent 20-s maximal sprints with a 60-s recovery period in between were performed. Maximal isometric voluntary contractions were performed at rest and immediately after each 20-s maximal sprint, and the force and EMG RMS amplitude were recorded from the vastus medialis and vastus lateralis muscles. For the incremental exercise test, no significant differences were found in the maximal power output (P=0.12), oxygen consumption (P=0.39), and heart rate (P=0.32) between Q-rings and C-rings. Throughout the incremental test, lactate levels were comparable when using both the C-rings and Q-rings (P=0.47). During the short sprints, power output was 2.5-6.5% greater for Q-rings than for C-rings (P=0.22). The decline in EMG RMS amplitude observed during the incremental tests was comparable for Q-rings and C-rings (0.42). These findings indicate that the oval chainring design, presented here as "Q-rings", did not significantly influence the physiological response to an incremental exercise test as compared to a conventional chainring. Key pointsDuring the incremental exercise test, no significant differences were found in power output, oxygen consumption or heart rate between oval "Q-rings" and conventional chainrings.Over the course of the incremental test, blood lactate levels were comparable for the oval "Q-rings" and conventional chainrings.During the short sprints performed after the incremental test, there were no statistical differences in power production between oval "Q-rings" and conventional chainrings.

Revista Investigacion En Educacion Medica, 2013

Uso y utilidad de la videoconferencia en la enseñanza de asignaturas preclínicas de medicina en l... more Uso y utilidad de la videoconferencia en la enseñanza de asignaturas preclínicas de medicina en la Universidad Latina de Panamá (ULAT)

Journal of sports science & medicine, 2016

Recently, a new method has been proposed to detect the onset of neuromuscular fatigue during an i... more Recently, a new method has been proposed to detect the onset of neuromuscular fatigue during an incremental cycling test by assessing the changes in spectral electromyographic (sEMG) frequencies within individual exercise periods of the test. The method consists on determining the highest power output that can be sustained without a significant decrease in spectral frequencies. This study evaluated the validity of the new approach by assessing the changes in spectral indicators both throughout the whole test and within individual exercise periods of the test. Fourteen cyclists performed incremental cycle ergometer rides to exhaustion with bipolar surface EMG signals recorded from the vastus lateralis. The mean and median frequencies (Fmean and Fmedian, respectively) of the sEMG power spectrum were calculated. The main findings were: (1) Examination of spectral indicators within individual exercise periods of the test showed that neither Fmean nor Fmedian decreased significantly duri...

The American Surgeon, Sep 1, 2012

Atheroscler Suppl, 2003

The purpose of this study was to investigate the influence of exercise intensity on the changes o... more The purpose of this study was to investigate the influence of exercise intensity on the changes of skeletal muscle capillary distribution after 5 (1 week) and 30 (6 weeks) training sessions.

Http Dx Doi Org 10 1080 02640410410001716742, Feb 18, 2007

Strenuous physical exercise of the limb muscles commonly results in damage, especially when that ... more Strenuous physical exercise of the limb muscles commonly results in damage, especially when that exercise is intense, prolonged and includes eccentric contractions. Many factors contribute to exercise-induced muscle injury and the mechanism is likely to differ with the type of exercise. Competitive sports players are highly susceptible to this type of injury. AM3 is an orally administered immunomodulator that reduces the synthesis of proinflammatory cytokines and normalizes defective cellular immune fractions. The ability of AM3 to prevent chronic muscle injury following strenuous exercise characterized by eccentric muscle contraction was evaluated in a double-blind and randomized pilot study. Fourteen professional male volleyball players from the First Division of the Spanish Volleyball League volunteered to take part. The participants were randomized to receive either placebo (n=7) or AM3 (n=7). The physical characteristics (mean+/-s) of the placebo group were as follows: age 25.7+/-2.1 years, body mass 87.2+/-4.1 kg, height 1.89+/-0.07 m, maximal oxygen uptake 65.3+/-4.2 ml.kg(-1).min(-1). Those of the AM3 group were as follows: age 26.1+/-1.9 years, body mass 85.8+/-6.1 kg, height 1.91+/-0.07 m, maximal oxygen uptake 64.6+/-4.5 ml.kg(-1).min(-1). All participants were evaluated for biochemical indices of muscle damage, including concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatine kinase (CK) and its MB fraction (CK-MB), myoglobin, lactate dehydrogenase, urea, creatinine and gamma-glutamyltranspeptidase, both before and 30 days after treatment (over the peak of the competitive season). In the placebo group, competitive exercise (i.e. volleyball) was accompanied by significant increases in creatine kinase (494+/-51 to 560+/-53 IU.l(-1), P < 0.05) and myoglobin (76.8+/-2.9 to 83.9+/-3.1 microg.l(-1), P < 0.05); aspartate aminotransferase (30.8+/-3.0 to 31.1+/-2.9 IU.l(-1)) and lactate dehydrogenase (380+/-31 to 376+/-29 IU.l(-1)) were relatively unchanged after the 30 days maximum effort. AM3 not only inhibited these changes, it led to a decrease from baseline serum concentrations of creatine kinase (503+/-49 to 316+/-37 IU.l(-1), P < 0.05) and myoglobin (80.1+/-3.2 to 44.1+/-2.6 IU.l(-1), P < 0.05), as well as aspartate aminotransferase (31.1+/-3.3 to 26.1+/-2.7 IU.l(-1), P…

Physiology Behavior, Jan 31, 2005

The aim of this work was to demonstrate the occurrence of oxidative stress during exhaustive exer... more The aim of this work was to demonstrate the occurrence of oxidative stress during exhaustive exercise and to determine the antioxidant response. Eight voluntary male subjects participated in this study. The exercise was a cycling mountain stage (171 km) and the cyclists took a mean+/-S.E.M. time of 270+/-12 min to complete it. Blood samples were taken before the cycling stage, immediately after the stage, 3 h after finishing the stage and on the morning of the following day. We determined the activities of erythrocyte antioxidant enzymes, blood levels of oxidised glutathione, plasma levels of antioxidant vitamins and carotenoids, and the serum lipid and cholesterol profile. The mountain cycling stage induced significant increases in catalase and glutathione reductase activities. Significant decreases in glutathione peroxidase activity, both determined with hydrogen peroxide and with cumene hydroperoxide as substrates, were observed. Blood oxidised glutathione and serum uric acid rose after the stage. Plasma vitamin E increased after the stage but dropped to below basal values after 3 h of recovery. Triglycerides and VLDL-cholesterol increased significantly after the stage and remained high 3 h after the cycling stage. The mountain cycling stage induced oxidative stress, as was evidenced by the increases in blood GSSG and in serum urate concentrations and by the pattern of change of erythrocyte antioxidant enzyme activities. A specific utilisation of alpha-tocopherol against oxidative stress during recovery was evidenced.

Investigacion En Educacion Medica, Mar 1, 2013

Physiology Behavior, 1992

Changes on plasmatic and erythrocytic magnesium levels after high-intensity exercises in men. PHY... more Changes on plasmatic and erythrocytic magnesium levels after high-intensity exercises in men. PHYSIOL BEHAV 52(4) [819][820][821] 1992.--The aim of this paper was investigate the effects of high-intensity exercise on plasmatic and erythrocytic Mg levels in men. Twelve normal male volunteers participated in this study. The tests were performed on a cycle-ergometer (Monark). The exercise programs consisted of: 1) triangular progressive test (TPT); 2) interval endurance test (IET), of 45 rain duration; and 3) maximal subtained test (MST), consisting of a maximal level, at 100% of MTP, for at least 7 rain. The percent change in plasma volume (%PV) after exercise was calculated. Magnesium levels in plasma and erythrocytes were measured by atomic absorption spectrophotometry. No significant differences in the absolute Mg concentration of plasma were noted for the three maximal exercises. The percentage increase in plasma Mg concentrations was about 5-7%; however, percent decrease of PV was more important (13-16%). Erythrocytic Mg levels were increased after all maximal exercises (TPT, IET, and MST), although absolute Mg concentrations were not significantly different.

Mineral and Electrolyte Metabolism, Feb 1, 1991

The pharmacological effects of glucagon (0.05 mg/kg b.wt. day) on serum calcium, magnesium and st... more The pharmacological effects of glucagon (0.05 mg/kg b.wt. day) on serum calcium, magnesium and strontium levels were analyzed in order to clarify the response of divalent cations to glucagon administration and its possible relation with calcitonin release stimulation. The results show significant decreases in serum calcium and strontium levels 2 h after glucagon administration, and in daily administration the effect peaks on the 3rd day and returns to baseline values by the 9th day. In contrast, the serum magnesium increases significantly by the 3rd day of daily glucagon administration and continues to increase until the 9th day. Calcitonin administration (90 mU Medical Research Council unit)/100 g b.wt.) significantly reduces the serum calcium, strontium and magnesium levels up to the 3rd day of treatment, just when the glucagon effect is highest. Other additional mechanisms may be involved besides the calcitonin release stimulation, in the response induced in divalent cations--particularly magnesium--by the exogenous administration of glucagon.

Journal of the American College of Surgeons, Nov 3, 2011

... 2011 Source: Journal of the American College of Surgeons, Available online 21 October 2011 El... more ... 2011 Source: Journal of the American College of Surgeons, Available online 21 October 2011 Elizabeth Kiwanuka, Florian Hackl, Justin Philip ... GMT. Publication year: 2011 Source: Journal of the American College of Surgeons, Available online 18 October 2011 Amanda L. Amin ...

European Journal of Applied Physiology, May 1, 2010

Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid ... more Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited L-arginine availability. Oral L-citrulline supplementation raises plasma L-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with L-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g L-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p < 0.05) and significantly decreased the isoleucine concentration from basal measures to after exercise (p < 0.05). Insulin levels significantly increased after exercise in both groups (p < 0.05) returning to basal values at recovery. Growth hormone increased after exercise in both groups, although the increase was higher in the citrulline-malate supplemented group (p < 0.05). L-citrulline-malate supplementation can enhance the use of amino acids, especially the branched chain amino acids during exercise and also enhance the production of arginine-derived metabolites such as nitrite, creatinine, ornithine and urea.

Amer J Pathol, 2006

ABSTRACT

Journal of Sports Sciences, Feb 18, 2007

The aims of this study were to examine the changes in plasma concentrations of inflammatory cytok... more The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.

Case Reports in Oncological Medicine, 2015

Introduction. Celiac disease is associated with an increased risk of small bowel malignancies, pa... more Introduction. Celiac disease is associated with an increased risk of small bowel malignancies, particularly lymphoma. Its association with small bowel carcinoma is less known.Case Description. We report a case of an 89-year-old woman with celiac disease who experienced recurrent episodes of gastrointestinal bleeding and was ultimately found to have adenocarcinoma of the small intestine.Discussion and Evaluation. Diagnosis of small bowel adenocarcinoma is often delayed because of the need for specialized modalities, which are often deferred in the inpatient setting. Although resection is the modality of choice for small bowel tumors, a majority is either locally advanced or metastatic at diagnosis, and even localized cancers have worse prognosis than stage-matched colorectal tumors. The role of adjuvant chemotherapy is uncertain, but it is often offered extrapolating data from other gastrointestinal cancers. Small bowel carcinomas occurring in the context of celiac disease appear to ...

Apunts Medicina De L Esport, 2010

Rebut el 17 de maig de 2010; acceptat el 10 de juny de 2010

J Surg Res, 2006

lular gap formation and increased permeability in endothelial monolayer. We hypothesize that the ... more lular gap formation and increased permeability in endothelial monolayer. We hypothesize that the three tyrosine residue(s) in the C terminus of VE cadherin (Y784, 774, and 757) are important for cadherin phosphorylation and cadherin-catenin dissociation. Methods: Human umbilical vein endothelial cells, HUVEC, were infected with adenoviral constructs containing either full length VE cadherin-GFP fusion protein (AdVEC-GFP), or C terminal truncated VE cadherin-GFP fusion protein (AdVEC-756), and then exposed to vehicle or VEGF (50ng/ml). VE cadherin was immunoprecipitated with GFP antibody and immunoblotted with anti-phosphotyrosine. Results: VEGF exposure caused phosphorylation of the full length VE cadherin-GFP fusion protein but failed to induce phosphorylation of the truncated construct. Conclusion: We conclude that one or more of the three tyrosine residues in the C terminus of VE cadherin regulate VEGF-induced VE cadherin phosphorylation and endothelial cell signaling.

Acta Zoologica Mexicana, 2000

Free Radical Research, Sep 1, 2007

We studied the effects of intense exercise on the neutrophil antioxidant enzyme activities and ge... more We studied the effects of intense exercise on the neutrophil antioxidant enzyme activities and gene expression. Blood samples were taken from seven cyclists in basal conditions and 3 h after two competition stages of 165 km. Serum creatine kinase (CK) activity, plasma carbonyl derivatives and uric acid levels increased after exercise. The cycling stage induced neutrophilia and increased myeloperoxidase (MPO) activity and reactive oxygen species (ROS) production. Antioxidant enzyme activities (catalase, glutathione peroxidase and superoxide dismutase) decreased after exercise, although gene expression increased. Immunocytochemistry showed catalase (CAT) enzyme equally distributed between the cytoplasm and organelles before exercise, and after exercise the cytoplasmic CAT levels were reduced and were absent in the compartments. After in vitro stimulation with opsonized zymosan (OZ) the extracellular CAT levels increased. This suggests a CAT secretion in order to avoid neutrophil-induced oxidative damage at a local level or to regulate the function of ROS as extracellular signalling molecules.

Membrane type 1-matrix metalloproteinase (MT1-MMP) plays a key role in extracellular matrix remod... more Membrane type 1-matrix metalloproteinase (MT1-MMP) plays a key role in extracellular matrix remodeling, endothelial cell (EC) migration, and angiogenesis. Whereas cyclic strain (CS) increases MT1-MMP expression, shear stress (SS) decreases MT1-MMP expression. The aim of this study was to determine if changes in levels of Sp1 phosphorylation induced by protein kinase Czeta (PKCzeta) in ECs exposed to SS but not CS are important for MT1-MMP expression. The results showed that SS increased Sp1 phosphorylation, which could be inhibited by pretreatment with PKCzeta inhibitors. In the presence of PKCzeta inhibitors, the SS-mediated decrease in MT1-MMP protein expression was also abolished. These data demonstrate that increased affinity of Sp1 for MT1-MMP's promoter site occurs as a consequence of PKCzeta-induced phosphorylation of Sp1 in response to SS, increasing Sp1 binding affinity for the promoter site, preventing Egr-1 binding, and consequently decreasing MT1-MMP expression.

Journal of Sports Science Medicine, May 1, 2014

The aim of this study was to compare the physiological responses of cyclists using round (C-ring)... more The aim of this study was to compare the physiological responses of cyclists using round (C-ring) or oval (Q-ring) chainrings during an incremental test until exhaustion. Following a randomized design, twelve male elite cyclists [age (mean ± SD): 21.1 ± 2.1 yr; VO2max: 78.1 ± 5.3 mL·kg(-1)min(-1)] performed two incremental maximal tests separated by 48 h (one with C-rings, the other with Q-rings). Starting at 100 W, the workload was increased by 25 W every 3 min until volitional exhaustion. Maximal heart rate, power output and oxygen consumption were compared. Blood lactate was monitored throughout the test. After the incremental test, 4 intermittent 20-s maximal sprints with a 60-s recovery period in between were performed. Maximal isometric voluntary contractions were performed at rest and immediately after each 20-s maximal sprint, and the force and EMG RMS amplitude were recorded from the vastus medialis and vastus lateralis muscles. For the incremental exercise test, no significant differences were found in the maximal power output (P=0.12), oxygen consumption (P=0.39), and heart rate (P=0.32) between Q-rings and C-rings. Throughout the incremental test, lactate levels were comparable when using both the C-rings and Q-rings (P=0.47). During the short sprints, power output was 2.5-6.5% greater for Q-rings than for C-rings (P=0.22). The decline in EMG RMS amplitude observed during the incremental tests was comparable for Q-rings and C-rings (0.42). These findings indicate that the oval chainring design, presented here as "Q-rings", did not significantly influence the physiological response to an incremental exercise test as compared to a conventional chainring. Key pointsDuring the incremental exercise test, no significant differences were found in power output, oxygen consumption or heart rate between oval "Q-rings" and conventional chainrings.Over the course of the incremental test, blood lactate levels were comparable for the oval "Q-rings" and conventional chainrings.During the short sprints performed after the incremental test, there were no statistical differences in power production between oval "Q-rings" and conventional chainrings.

Revista Investigacion En Educacion Medica, 2013

Uso y utilidad de la videoconferencia en la enseñanza de asignaturas preclínicas de medicina en l... more Uso y utilidad de la videoconferencia en la enseñanza de asignaturas preclínicas de medicina en la Universidad Latina de Panamá (ULAT)

Journal of sports science & medicine, 2016

Recently, a new method has been proposed to detect the onset of neuromuscular fatigue during an i... more Recently, a new method has been proposed to detect the onset of neuromuscular fatigue during an incremental cycling test by assessing the changes in spectral electromyographic (sEMG) frequencies within individual exercise periods of the test. The method consists on determining the highest power output that can be sustained without a significant decrease in spectral frequencies. This study evaluated the validity of the new approach by assessing the changes in spectral indicators both throughout the whole test and within individual exercise periods of the test. Fourteen cyclists performed incremental cycle ergometer rides to exhaustion with bipolar surface EMG signals recorded from the vastus lateralis. The mean and median frequencies (Fmean and Fmedian, respectively) of the sEMG power spectrum were calculated. The main findings were: (1) Examination of spectral indicators within individual exercise periods of the test showed that neither Fmean nor Fmedian decreased significantly duri...

The American Surgeon, Sep 1, 2012

Atheroscler Suppl, 2003

The purpose of this study was to investigate the influence of exercise intensity on the changes o... more The purpose of this study was to investigate the influence of exercise intensity on the changes of skeletal muscle capillary distribution after 5 (1 week) and 30 (6 weeks) training sessions.

Http Dx Doi Org 10 1080 02640410410001716742, Feb 18, 2007

Strenuous physical exercise of the limb muscles commonly results in damage, especially when that ... more Strenuous physical exercise of the limb muscles commonly results in damage, especially when that exercise is intense, prolonged and includes eccentric contractions. Many factors contribute to exercise-induced muscle injury and the mechanism is likely to differ with the type of exercise. Competitive sports players are highly susceptible to this type of injury. AM3 is an orally administered immunomodulator that reduces the synthesis of proinflammatory cytokines and normalizes defective cellular immune fractions. The ability of AM3 to prevent chronic muscle injury following strenuous exercise characterized by eccentric muscle contraction was evaluated in a double-blind and randomized pilot study. Fourteen professional male volleyball players from the First Division of the Spanish Volleyball League volunteered to take part. The participants were randomized to receive either placebo (n=7) or AM3 (n=7). The physical characteristics (mean+/-s) of the placebo group were as follows: age 25.7+/-2.1 years, body mass 87.2+/-4.1 kg, height 1.89+/-0.07 m, maximal oxygen uptake 65.3+/-4.2 ml.kg(-1).min(-1). Those of the AM3 group were as follows: age 26.1+/-1.9 years, body mass 85.8+/-6.1 kg, height 1.91+/-0.07 m, maximal oxygen uptake 64.6+/-4.5 ml.kg(-1).min(-1). All participants were evaluated for biochemical indices of muscle damage, including concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatine kinase (CK) and its MB fraction (CK-MB), myoglobin, lactate dehydrogenase, urea, creatinine and gamma-glutamyltranspeptidase, both before and 30 days after treatment (over the peak of the competitive season). In the placebo group, competitive exercise (i.e. volleyball) was accompanied by significant increases in creatine kinase (494+/-51 to 560+/-53 IU.l(-1), P < 0.05) and myoglobin (76.8+/-2.9 to 83.9+/-3.1 microg.l(-1), P < 0.05); aspartate aminotransferase (30.8+/-3.0 to 31.1+/-2.9 IU.l(-1)) and lactate dehydrogenase (380+/-31 to 376+/-29 IU.l(-1)) were relatively unchanged after the 30 days maximum effort. AM3 not only inhibited these changes, it led to a decrease from baseline serum concentrations of creatine kinase (503+/-49 to 316+/-37 IU.l(-1), P < 0.05) and myoglobin (80.1+/-3.2 to 44.1+/-2.6 IU.l(-1), P < 0.05), as well as aspartate aminotransferase (31.1+/-3.3 to 26.1+/-2.7 IU.l(-1), P…

Physiology Behavior, Jan 31, 2005

The aim of this work was to demonstrate the occurrence of oxidative stress during exhaustive exer... more The aim of this work was to demonstrate the occurrence of oxidative stress during exhaustive exercise and to determine the antioxidant response. Eight voluntary male subjects participated in this study. The exercise was a cycling mountain stage (171 km) and the cyclists took a mean+/-S.E.M. time of 270+/-12 min to complete it. Blood samples were taken before the cycling stage, immediately after the stage, 3 h after finishing the stage and on the morning of the following day. We determined the activities of erythrocyte antioxidant enzymes, blood levels of oxidised glutathione, plasma levels of antioxidant vitamins and carotenoids, and the serum lipid and cholesterol profile. The mountain cycling stage induced significant increases in catalase and glutathione reductase activities. Significant decreases in glutathione peroxidase activity, both determined with hydrogen peroxide and with cumene hydroperoxide as substrates, were observed. Blood oxidised glutathione and serum uric acid rose after the stage. Plasma vitamin E increased after the stage but dropped to below basal values after 3 h of recovery. Triglycerides and VLDL-cholesterol increased significantly after the stage and remained high 3 h after the cycling stage. The mountain cycling stage induced oxidative stress, as was evidenced by the increases in blood GSSG and in serum urate concentrations and by the pattern of change of erythrocyte antioxidant enzyme activities. A specific utilisation of alpha-tocopherol against oxidative stress during recovery was evidenced.

Investigacion En Educacion Medica, Mar 1, 2013

Physiology Behavior, 1992

Changes on plasmatic and erythrocytic magnesium levels after high-intensity exercises in men. PHY... more Changes on plasmatic and erythrocytic magnesium levels after high-intensity exercises in men. PHYSIOL BEHAV 52(4) [819][820][821] 1992.--The aim of this paper was investigate the effects of high-intensity exercise on plasmatic and erythrocytic Mg levels in men. Twelve normal male volunteers participated in this study. The tests were performed on a cycle-ergometer (Monark). The exercise programs consisted of: 1) triangular progressive test (TPT); 2) interval endurance test (IET), of 45 rain duration; and 3) maximal subtained test (MST), consisting of a maximal level, at 100% of MTP, for at least 7 rain. The percent change in plasma volume (%PV) after exercise was calculated. Magnesium levels in plasma and erythrocytes were measured by atomic absorption spectrophotometry. No significant differences in the absolute Mg concentration of plasma were noted for the three maximal exercises. The percentage increase in plasma Mg concentrations was about 5-7%; however, percent decrease of PV was more important (13-16%). Erythrocytic Mg levels were increased after all maximal exercises (TPT, IET, and MST), although absolute Mg concentrations were not significantly different.

Mineral and Electrolyte Metabolism, Feb 1, 1991

The pharmacological effects of glucagon (0.05 mg/kg b.wt. day) on serum calcium, magnesium and st... more The pharmacological effects of glucagon (0.05 mg/kg b.wt. day) on serum calcium, magnesium and strontium levels were analyzed in order to clarify the response of divalent cations to glucagon administration and its possible relation with calcitonin release stimulation. The results show significant decreases in serum calcium and strontium levels 2 h after glucagon administration, and in daily administration the effect peaks on the 3rd day and returns to baseline values by the 9th day. In contrast, the serum magnesium increases significantly by the 3rd day of daily glucagon administration and continues to increase until the 9th day. Calcitonin administration (90 mU Medical Research Council unit)/100 g b.wt.) significantly reduces the serum calcium, strontium and magnesium levels up to the 3rd day of treatment, just when the glucagon effect is highest. Other additional mechanisms may be involved besides the calcitonin release stimulation, in the response induced in divalent cations--particularly magnesium--by the exogenous administration of glucagon.

Journal of the American College of Surgeons, Nov 3, 2011

... 2011 Source: Journal of the American College of Surgeons, Available online 21 October 2011 El... more ... 2011 Source: Journal of the American College of Surgeons, Available online 21 October 2011 Elizabeth Kiwanuka, Florian Hackl, Justin Philip ... GMT. Publication year: 2011 Source: Journal of the American College of Surgeons, Available online 18 October 2011 Amanda L. Amin ...

European Journal of Applied Physiology, May 1, 2010

Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid ... more Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited L-arginine availability. Oral L-citrulline supplementation raises plasma L-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with L-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g L-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p < 0.05) and significantly decreased the isoleucine concentration from basal measures to after exercise (p < 0.05). Insulin levels significantly increased after exercise in both groups (p < 0.05) returning to basal values at recovery. Growth hormone increased after exercise in both groups, although the increase was higher in the citrulline-malate supplemented group (p < 0.05). L-citrulline-malate supplementation can enhance the use of amino acids, especially the branched chain amino acids during exercise and also enhance the production of arginine-derived metabolites such as nitrite, creatinine, ornithine and urea.

Amer J Pathol, 2006

ABSTRACT

Journal of Sports Sciences, Feb 18, 2007

The aims of this study were to examine the changes in plasma concentrations of inflammatory cytok... more The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.

Case Reports in Oncological Medicine, 2015

Introduction. Celiac disease is associated with an increased risk of small bowel malignancies, pa... more Introduction. Celiac disease is associated with an increased risk of small bowel malignancies, particularly lymphoma. Its association with small bowel carcinoma is less known.Case Description. We report a case of an 89-year-old woman with celiac disease who experienced recurrent episodes of gastrointestinal bleeding and was ultimately found to have adenocarcinoma of the small intestine.Discussion and Evaluation. Diagnosis of small bowel adenocarcinoma is often delayed because of the need for specialized modalities, which are often deferred in the inpatient setting. Although resection is the modality of choice for small bowel tumors, a majority is either locally advanced or metastatic at diagnosis, and even localized cancers have worse prognosis than stage-matched colorectal tumors. The role of adjuvant chemotherapy is uncertain, but it is often offered extrapolating data from other gastrointestinal cancers. Small bowel carcinomas occurring in the context of celiac disease appear to ...