Leucocytosis as a marker of organ damage induced by chronic strenuous physical exercise

Effects of acute and chronic exercise on the osmotic stability of erythrocyte membrane of competitive swimmers

This study aimed to evaluate the influence of acute and chronic exercise on erythrocyte membrane stability and various blood indices in a population consisting of five national-level male swimmers, over 18 weeks of training. The evaluations were made at the beginning and end of the 1st, 7th, 13th and 18th weeks, when volume and training intensity have changed. The effects manifested at the beginning of those weeks were considered due to chronic adaptations, while the effects observed at the end of the weeks were considered due to acute manifestations of the exercise load of that week. Acute changes resulting from the exercise comprised increases in creatine kinase activity (CK) and leukocyte count (Leu), and decrease in hematocrit (Ht) and mean corpuscular volume (MCV), at the end of the first week; increase in the activities of CK and lactate dehydrogenase (LDH), in the uric acid (UA) concentration and Leu count, at the end of the seventh week; increases in CK and LDH activities and in the mean corpuscular hemoglobin concentration (MCHC), at the end of the 13th week; and decrease in the value of the osmotic stability index 1/H₅₀ and increases in the CK activity and platelets (Plt) count, at the end of the 18th week. Chronic changes due to training comprised increase in the values of 1/H₅₀, CK, LDH, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), serum iron (Fe), MCV and Plt. Although acute training has resulted in decrease in the osmotic stability of erythrocytes, possibly associated with exacerbation of the oxidative processes during intense exercise, chronic training over 18 weeks resulted in increased osmotic stability of erythrocytes, possibly by modulation in the membrane cholesterol content by low and high density lipoproteins.

Effects of unaccustomed downhill running on muscle damage, oxidative stress, and leukocyte apoptosis

[Purpose]

The purpose of this study was to investigate the effect of unaccustomed downhill running on muscle damage, oxidative stress, and leukocyte apoptosis.

[Methods]

Thirteen moderately trained male subjects performed three 40 min treadmill runs at ~70% VO_2max on separate days: a level run (L) followed by two downhill runs (DH1 and DH2). Blood samples were taken at rest (PRE) and immediately (POST), 2 h, 24 h, and 48 h after each run. Data were analyzed using 2-way repeated measures ANOVA with post hoc Tukey tests.

[Results]

Creatine kinase (CK) activity and oxidative stress level were significantly elevated at 24 h and 48 h following DH1 (P < 0.05). The level of oxidative stress at the POST measurement following DH1 and DH2 was greater than PRE. The rate of leukocyte apoptosis was significantly increased at the POST measurement following all three runs, and remained elevated for up to 48 h following DH1 (P < 0.01).

[Conclusion]

CK activity and oxidative stress were elevated following an acute bout of moderate intensity downhill running, resulting in a greater apoptotic response at 24 h and 48 h post-exercise in comparison with level grade running or a second downhill run. These elevations were blunted following DH2. Although the link between exercise-induced muscle damage and leukocyte apoptosis is currently unknown, the differential response to DH1 vs. L and DH2 indicates that it may be mediated by the elevation of oxidative stress.

Acute funisitis is associated with distinct changes in fetal hematologic profile

OBJECTIVE

Acute funisitis is a histologic hallmark of the fetal inflammatory response syndrome. This study was conducted to examine the hematologic profiles of preterm newborns with funisitis.

METHODS

The hematologic profiles of umbilical cord blood obtained at birth were compared according to the presence or absence of acute funisitis in 197 preterm neonates (gestational age before 34 weeks) born to mothers with preterm labor with intact membranes or premature rupture of membranes.

RESULTS

(1) Funisitis was identified in 22.3% (44/197) of patients; (2) newborns with funisitis had higher median leukocyte, neutrophil, monocyte counts (p < 0.005 for each), higher rate of neutrophilia (p < 0.05), higher proportion of neutrophils among leukocytes and lower proportion of lymphocytes among leukocytes than those without funisitis (p < 0.01 for each); (3) newborns with funisitis had a significantly lower median RBC count, hemoglobin concentration and hematocrit than those without funisitis (p < 0.05 for each); (4) there was no significant difference in the median lymphocyte, eosinophil, basophil, NRBC and platelet counts between the two groups (p > 0.1 for each).

CONCLUSIONS

The hematologic profiles of preterm newborns with funisitis are characterized by increased total white blood cell, neutrophil, and monocyte counts and decreased RBC count and hemoglobin concentration.

Dano muscular e perfil imunológico no triatlo ironman Brasil

INTRODUÇÃO: O triatlo Ironman se caracteriza por ser uma atividade de longa duração em que alterações orgânicas agudas estão presentes. OBJETIVO: verificar a ocorrência de dano muscular e sua relação com o perfil imunológico em triatletas do Ironman - Brasil. MÉTODOS: A amostra de sangue foi obtida de 21 atletas em três momentos: dois dias antes da prova (pré), imediatamente após a prova (pós) e seis dias após a prova (seis dias pós), em que foram analisadas de forma isolada as variáveis creatinoquinase (CK), os leucócitos totais, linfócitos, subtipos de linfócitos CD4+ e CD8+, e relação CD4+/CD8+ e a correlação da CK como marcador de dano muscular, com as demais variáveis. RESULTADOS: As diferenças significativas foram observadas nos leucócitos pré (média: 6.242,9 mm³; DP: 1.233,3) e pós (média: 18.398,1 mm³; DP: 3.904,0; p < 0,0001); pós (média: 18.398,1 mm³; DP: 3.904,0) e seis dias pós (média: 6.396,4 mm³; DP: 1.299,8; p < 0,0001); CK pré (média: 173,2 U/l; DP: 103,7) e pós (média: 2.339,4 U/l; DP: 1.729,0; p < 0,0001), CK pré (média: 173,2 U/l; DP: 103,7) e seis dias pós (média: 368,1 U/l; DP: 274,4; p < 0,0053); CK pós (média: 2.339,4 U/l; DP: 1.729,0) e seis dias pós (média: 368,1 U/l; DP: 274,4; p < 0,0003); CD4+/CD8+ pré (média: 1,9; DP: 0,8) e seis dias pós (média: 2,4; DP: 1,1: p < 0,00032). CONCLUSÃO: Houve dano muscular no período pós-prova imediato e melhora do perfil imunológico após o sexto dia.

Chronic stress-induced oxidative damage and hyperlipidemia are accompanied by atherosclerotic development in rats

Although stress-induced hyperlipidemia and increased oxidative stress have been reported and implicated in etiology of atherosclerosis, experimental evidence for stress-induced atherosclerotic development concomitant with these alterations is lacking. In this study, exposure of adult male albino Wistar rats (Rattus norvegicus) to restraint for 1 h and after a gap of 4 h to forced swimming for 15 min every day for 2, 4, or 24 weeks resulted in a duration of exposure-dependent hyperlipidemia as shown by significant increases in concentrations of blood cholesterol, low-density lipoproteins, and triglycerides and decrease in high-density lipoprotein concomitant with increased oxidative stress as indicated by decrease in hepatic antioxidant enzyme activities and increase in lipid peroxidation in the liver, kidney, and heart. These alterations were accompanied by development of fibrous layer, formation of foam cells, reduction in elastic fibers, and accumulation of Oil-Red-O-positive lipid droplets in the intima of thoracic aorta following 24 weeks of stress exposure, but not after 4 weeks. The study demonstrates for the first time that (i) chronic stress-induced hyperlipidemia and oxidative damage are coupled with atherosclerotic development in rats fed with normal diet and (ii) chronic stress effects prevail even after the cessation of stress exposure as indicated by high concentration of blood cholesterol and reduced hepatic superoxide dismutase activity 20 weeks after 2 or 4 weeks of stress. This study exemplifies long-term allostatic regulation leading to a pathological state, with long-term hyperlipidemia and oxidative damage from chronic stress resulting in atherosclerosis.

The effect of hyperthermia on blood glutamate levels

INTRODUCTION

Glutamate neurotoxicity is determined by the balance between glutamate release within the brain and efflux of excess glutamate from the brain. Brain-to-blood efflux of glutamate is increased by decreasing the concentration of glutamate in blood. Little is known about the effect of hyperthermia on blood glutamate concentrations, and the effectiveness of blood glutamate-decreasing mechanisms in these conditions. Although hyperthermia is hypothesized to decrease blood glutamate concentrations by activation of stress mechanisms, blunting the stress response by blocking β-adrenergic receptors should prevent this decrease. Furthermore, during hyperthermia there should be a concurrent process of leakage of glutamate from muscle tissue into blood, resulting in a contradictory increase of blood glutamate concentrations. In this study we investigated the effects of hyperthermia on blood glutamate levels and studied the effects of the β-adrenergic receptor antagonist propranolol on stress-induced changes in glutamate levels. We then studied the effectiveness of the blood glutamate scavenger oxaloacetate on hyperthermia-induced increases of glutamate levels.

MATERIALS AND METHODS

Twenty-four rats were randomly divided into 3 groups. Rats' body temperatures were increased (by 1°C every 40 minutes) from 37°C to 42°C. The first group received 1 mL per 100 g of isotonic saline (control). The second group received 1 mL per 100 g of 1M oxaloacetate when the temperature reached 39°C. The third group received 10 mg/kg of propranolol before initiation of the warming.

RESULTS

Warming the rats from 37°C to 39°C decreased the blood glutamate levels in the control group (P < 0.01) and oxaloacetate treatment group (P < 0.0001), whereas further increases in temperature from 40°C to 42°C increased the blood glutamate levels (P < 0.01 and P < 0.0001, respectively). Pretreatment with propranolol prevented the decrease in blood glutamate concentrations seen in mild hyperthermia and did not affect the increase in blood glutamate levels seen at temperatures of 41°C and 42°C (P < 0.005).

DISCUSSION

The results of this study demonstrated that hyperthermia leads to decreases in glutamate levels in the blood, presumably by activation of the sympathetic nervous system. Oxaloacetate, previously reported to reduce blood glutamate levels at 37°C, was ineffective at temperatures over 40°C. Propranolol pretreatment blunted the initial decrease in blood glutamate, and thereafter had no effect when compared with control and treatment groups. Understanding the mechanisms underlying glutamate regulation in the blood during states of hyperthermia and stress has important clinical implications in treating neurodegenerative conditions.

Leukocytosis as a predictor for non-infective mortality and morbidity

Leukocytosis (raised concentration of white cells in the blood) is commonly associated with infection or inflammation, but can occur in a wide variety of other conditions. Leukocytosis has also been linked with increased mortality and morbidity in a number of studies. We have systematically reviewed the relevant literature, which clearly demonstrates an association between leukocytosis and mortality-particularly due to cardiovascular or cerebrovascular causes. The mechanisms of this effect are uncertain but, when combined with other markers predictive of death, leukocytosis may contribute to modelling systems to predict in-patient mortality risk.

Release of alpha-actin into serum after skeletal muscle damage

OBJECTIVE

The skeletal muscle protein alpha-actin was investigated in the serum of subjects with severe skeletal muscle damage to assess its utility as a reliable and predictive marker of muscle damage.

METHODS

Serum samples were obtained from 33 healthy controls and 33 patients with severe skeletal muscle damage, defined by a total creatine kinase value of >500 IU/l (Rosalki method). Troponin I, troponin T, and myoglobin concentrations were determined by immunoassay and alpha-actin concentrations by Western blot and densitometry.

RESULTS

The mean serum concentration of alpha-actin in controls and patients with skeletal muscle damage was 600.9 and 1968.51 ng/ml, respectively, a statistically significant difference. Sera of patients with muscle damage showed higher levels of alpha-actin than of troponin or myoglobin. No significant difference in troponin I levels was observed between the groups.

CONCLUSIONS

According to these results, alpha-actin was the most significant skeletal muscle damage marker analysed and may be an ideal candidate for the identification of all types of myofibre injury, including sports injuries. Our findings support the use of alpha-actin as a marker alongside other currently used biological proteins.

Effects of eccentric exercise-induced muscle injury on blood levels of platelet activating factor (PAF) and other inflammatory markers

It has been reported that exercise with eccentric contractions can induce damage and inflammation in human muscle tissue, the severity of which depends on the duration and the intensity of exercise. Platelet activating factor (PAF) is a potent inflammatory mediator implicated in a series of pathophysiological conditions. We sought to investigate the relationship between PAF and eccentric exercise induced muscle damage. Thirteen healthy, recreationally active male subjects (27.5+/-3.78 year) performed 36 maximum voluntary eccentric contractions on a motorized muscle dynamometer using the elbow flexor muscles of the non-dominant arm. Venous blood samples were collected immediately before and after exercise at 2, 24, 48, 72 and 96 h. PAF was isolated, purified and determined by a platelet aggregation assay. Serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP) and complement C3 (C3), plasma level of fibrinogen and whole blood level of leukocytes (and their subsets) were determined. Established indicators of muscle damage as maximum isometric torque (MIT), range of motion (ROM), relaxed arm angle (RANG), flexed arm angle (FANG), arm circumference (CIRC) and muscle soreness were also measured at the same time points. PAF, leukocytes, CK and LDH were elevated after exercise, while other biochemical parameters such as CRP, C3 and fibrinogen were unchanged. We also observed an inverse association between PAF and MIT and ROM, as well as a positive association with other markers of muscle injury, i.e. CK, LDH, FANG and CIRC (all P's<0.05). Our findings may imply a role for PAF in the mechanism of eccentric exercise induced muscle damage.

Reversible Neuropathy Caused by Overuse Following Radiofrequency Ablation of Metastatic Pelvic Lesions

Adverse events following radiofrequency ablation of skeletal metastases are uncommon. This report describes two patients who developed a delayed neuropathy following radiofrequency ablation of pelvic metastases. Both patients had significant pain relief and normal neurological examinations following the procedure. Each patient's neuropathy developed following acute significant increases of activity or stress on surrounding tissues allowed by the pain relief from therapy. Both patients completely recovered after a course of corticosteroids.

Performance enhancement with maintenance of resting immune status after intensified cycle training

BACKGROUND

Unaccustomed intense endurance exercise is associated with short-term suppression of natural immunity. However, it is not established whether intensified endurance training alters resting immune status or increases the risk of upper respiratory infection (URI).

PURPOSE

This study examined the effect of intensified endurance training for performance enhancement on resting immune status in nine healthy, male competitive cyclists.

DESIGN

Data were collected during 4 weeks of usual training (baseline), followed by prescribed cycle training that consisted of volume-building at customary training intensity (V phase, 6 weeks), unaccustomed very high intensity interval training at 100% maximal heart rate (I phase, 18 days), and an unloading taper (U phase, 10 days).

METHODS

The main performance criterion was a simulated 20 km time-trial. Aerobic capacity measures included power output at ventilatory threshold (POT(vent)) and maximal oxygen uptake (VO(2max)). Markers of immune status (lymphocyte subset counts, serum cytokine levels, and new URI cases) and physiological indicators of training stress (cycling economy, 24-hour urinary cortisol excretion, and serum testosterone concentration) were evaluated in the rested state, 36 to 44 hours postexercise, during baseline, and after each training phase.

RESULTS

Time-trial performance, POT9(vent), VO(2max), and cycling economy improved significantly (p < 0.001) after the V phase, and remained higher than baseline (p < 0.001) after the I and U phases. As compared with the V phase, performance time was faster after the U phase (p < 0.01). In contrast, lymphocyte counts, cytokine levels, incidence of URI, cortisol excretion, and serum testosterone concentration were not significantly different from baseline in any phase.

CONCLUSIONS

Cycling efficiency and performance improved while resting immune status was maintained throughout the 10-week training program. This study provides encouraging data in support of immunological robustness during intensified endurance training.

Exercise-induced muscle damage and inflammation: fact or fiction?

Physical exercise is necessary for maintaining normal function of skeletal muscle. The mechanisms governing normal muscle function and maintenance are vastly unknown but synergistic function of hormones, neurosignalling, growth factors, cytokines and other factors, is undoubtedly important. Because of the complex interaction among these systems the lack of complete understanding of muscle function is not surprising. The purpose of exercise-induced changes in muscle cell function is to adapt the tissue to a demand of increased physical work capacity. Some of the approaches used to investigate changes in skeletal muscle cell function are exercise and electrical stimulation in animals and human models and isolated animal muscle. From these models, it has been concluded that during physical exercise, in an intensity and duration dependent manner, skeletal muscle is damaged and subsequently inflamed. The purpose of the inflammation would be to repair the exercise-induced damage. Because of the design and methods used in a majority of these studies, concerns must be raised, and the question asked whether the paradigm of exercise-induced muscle inflammation in fact is fiction. In a majority of conducted studies, a non-exercising control group is lacking and because of the invasive nature of the sampling methods used to study inflammation it does not appear impossible that observed inflammatory events in human skeletal muscle after physical exercise are methodological artefacts.

Clinical safety of SonoVue, a new contrast agent for ultrasound imaging, in healthy volunteers and in patients with chronic obstructive pulmonary disease

RATIONALE AND OBJECTIVES

To evaluate the safety profile of SonoVue, a new echo-contrast agent based on stabilized sulfur hexafluoride (SF6) microbubbles, in healthy volunteers and in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Safety and tolerability of SonoVue were evaluated in 66 healthy volunteers during two placebo-controlled phase I studies (a single intravenous ascending-dose study in 36 volunteers given SonoVue doses of 0.003 to 0.12 mL/kg and a multiple-dose study in 30 subjects given cumulative doses of 0.15 to 0.6 mL/kg) and in 12 patients with COPD of various degrees of clinical severity, who were given SonoVue at a dosage of 4 mL (corresponding to 0.057 mL/kg in a 70-kg patient). Adverse events were monitored up to 48 to 72 hours after administration. All volunteers underwent extensive safety assessments (monitoring of vital signs, electrocardiogram, blood oxygen saturation, laboratory assessments, and Mini-Mental test) up to 24 to 72 hours after administration. In addition, patients with COPD underwent specific lung function tests, such as forced expiratory volume, forced vital capacity, and forced midexpiratory flow.

RESULTS

No serious adverse events occurred throughout the study. All nonserious adverse events were minor, mild, and rapidly self-resolving. No difference in the incidence of adverse events was observed among the various dosages of SonoVue and between SonoVue and placebo. There were no clinically significant changes in any of the safety assessments. No statistically significant differences between SonoVue and placebo were observed in mean forced expiratory volume, forced vital capacity, or forced midexpiratory flow levels. No substantial changes from baseline in blood oxygen saturation were observed for either study agent at any postinjection time point.

CONCLUSIONS

SonoVue showed a good safety profile both in healthy subjects and in patients with COPD.

Regulation of MAC-1 (CD11b/CD18) expression on circulating granulocytes in endurance runners

PURPOSE

We tested the hypothesis that degranulation of granulocytes and upregulation of the granulocyte integrin MA-1 (CD11b/CD18) are related to exercise duration and/or intensity. We also investigated whether or not the expression of MAC-1 would be influenced by body temperature or dehydration. Moreover, we tested the hypothesis that changes in leukocyte counts and changes in MAC1 expression with endurance exercise are independently regulated.

METHODS

In eight amateur runners, MAC-1 (CD11b/CD18) surface expression on granulocytes was determined by fluorescent antibody cell sorting, before and after an incremental maximal treadmill test, a moderate 3-h run, and a competitive marathon race.

RESULTS

Expression CD11b on granulocytes was increased by 10+/-9.6% (P < 0.05) after the maximal treadmill test and by 84+/-76% (P < 0.01) after the marathon run. There was no change in CD11b expression after the moderate 3-h run. CD18 expression was not significantly changed after any of the exercise protocols.

CONCLUSION

Expression of CD11b on granulocytes is increased with intense endurance exercise, either incremental maximal treadmill testing or competitive marathon running, but not in moderate endurance training. Thus, exhaustive exercise may be one mechanism for the upregulation of integrin adhesive receptors on granulocytes. This phenomenon could be in part responsible for increased adhesion of granulocytes to endothelial cells and could facilitate tissue infiltration after endurance exercise.

Effects of eccentric exercise on the immune system in men

The effects of eccentric exercise on changes in numbers of circulating leukocytes, cell activation, cell adhesion, and cellular memory function were investigated in 12 men, aged 22-35 yr. The immunologic effects of postexercise epidermal treatment with monochromatic, infrared light were also evaluated. Blood was drawn before and 6, 24, and 48 h after exercise for phenotyping and analysis of creatine kinase activity. There was an increase in leukocyte, monocyte, and neutrophil number, no change in the number of basophils, eosinophils, B cells, and T cells, and a decrease in natural killer cell number postexercise. Some markers of lymphocyte and monocyte activation remained unchanged or decreased, whereas the expression of adhesion molecules 62L and 11b increased on monocytes. It is concluded that eccentric exercise induced decreased activation, and increased cell adhesion capacity, of monocytes. Altered trafficking of cells between lymphoid tissue and blood, selective apoptosis, or attachment/detachment from the endothelial wall can explain the observed phenotypic changes. Treatment with monochromatic, infrared light did not significantly affect any of the investigated variables. Correlations between immunologic and physiological parameters indicate a role of the immune system in adaptation to physical exercise.

Changes in indicators of inflammation after eccentric exercise of the elbow flexors

This study examined muscle swelling and changes in inflammatory markers in the blood following eccentric exercise-induced muscle damage. Subjects (N = 14) who had not been involved in a resistance training program performed 24 maximal eccentric actions of the elbow flexors. Muscle swelling was assessed by measures of the upper arm circumference (CIR), ultrasonography (USG), and magnetic resonance imaging (MRI). Plasma concentrations of interleukin-1 alpha, interleukin-1 beta, interleukin-2, interleukin-6, tumor necrosis factor-alpha, and plasma levels of C-reactive protein, cortisol, and zinc were analyzed. Established indicators of muscle damage (maximal isometric force, range of motion, muscle soreness, and plasma creatine kinase, aspartate aminotransferase, and lactate dehydrogenase activities) were also measured. All measures, including CIR and USG, except for MRI, were assessed immediately before and after and for 5 d post-exercise. MRI was taken at pre- and 1, 3, 6, 10, 23, 31, and 58 d post-exercise. All muscle damage indicators changed significantly after exercise. A large increase in CIR (> 20 mm) was found 4-5 d after exercise, and this coincided with USG, showing an increase in muscle thickness. The echointensity of USG increased with the enlargement of the elbow flexors. MRI displayed enlargement of the biceps brachii and brachialis cross-sectional area that started at 1 d, and lasted until 23 d, post-exercise. The most profound increase in the enlargement and signal intensity of the MRI was found 3 or 6 d after exercise. However, none of the plasma levels of inflammatory makers showed significant muscle swelling, which is indicative of muscle edema, but the inflammatory responses after exercise appear to be different from those accompanying infection or tissue injury.

Superoxide dismutase derivative prevents oxidative damage in liver and kidney of rats induced by exhausting exercise

To prevent oxidative tissue damage induced by strenuous exercise in the liver and kidney superoxide dismutase derivative (SM-SOD), which circulated bound to albumin with a half-life of 6 h, was injected intraperitoneally into rats. Exhausting treadmill running caused a significant increase in the activities of xanthine oxidase (XO), and glutathione peroxidase (GPX) in addition to concentrations of thiobarbituric acid-reactive substances (TBARS) in hepatic tissue immediately after running. There was a definite increase in the immunoreactive content of mitochondrial superoxide dismutase (Mn-SOD) 1 day after the running. Meanwhile, the TBARS concentration in the kidney was markedly elevated 3 days after running. The activities of GPX, and catalase in the kidney increased significantly immediately and on days 1 and 3 following the test. The immunoreactive content of Mn-SOD also increased 1 day after running. The exercise induced no significant changes in immunoreactive Cu, Zn-SOD content in either tissue. The administration of SM-SOD provided effective protection against lipid peroxidation, and significantly attenuated the alterations in XO and all the anti-oxidant enzymes, measured. In summary, the present data would suggest that exhausting exercise may induce XO-derived oxidative damage in the liver, while the increase in lipid peroxidation in the kidney might be the result of washout-dependent accumulation of peroxidised metabolites. We found that the administration of SM-SOD provided excellent protection against exercise-induced oxidative stress in both liver and kidney.