Adaptive stress response of glutathione and uric acid metabolism in man following controlled exercise and diet.

Ergometer cycling performance as well as acute exercise-induced changes in the metabolism of energy-intermediates and glutathione (GSH) were investigated in skeletal muscle (SM) of 15 healthy young male subjects (VO(2max) approximately 54.7 mL kg(-1) min(-1), age approximately 25 years), before and after 3 days of controlled 'ìoverload-training' in combination with either high (62% of energy intake) or low (26% of energy intake) dietary intake of carbohydrates. The intake of a carbohydrate-rich diet clearly reduced the depletion of SM glycogen following the short-term training period, paralleled with a positive effect on the endurance performance, but not on high-intensity work-performance. An 'delayed over-reaching effect', defined as impaired work-performance, was observed after 2.5 days of recovery from the short-term training period, irrespective of the carbohydrate content of the diet and basal glycogen level in SM. Taken together, the main and novel findings of present investigation are: (1) an acute decrease of reduced GSH content and altered thiol-redox homeostasis in SM induced by strenuous high-intensity exercise; (2) an adaptive elevation of basal GSH level following the short-term training period; (3) an adaptive decrease of basal GSH level following 2.5 days recovery from training; (4) evidence of a relationship between the SM fibre type, physical performance capacity and GSH turnover during acute bouts of exercise; and (5) no evident effect of the level of carbohydrate intake on metabolism of GSH or energy intermediates. Furthermore, the induction of acute oxidative stress in exercising human SM and the adaptive responses to training are suggested to provide a protective antioxidant phenotype to the exercising SM during periods with repeated intense intermittent training.

Allantoin formation and urate and glutathione exchange in human muscle during submaximal exercise.

Seven males performed two exhaustive cycling bouts (EX1 and EX2) at a work-rate of 90% of maximal oxygen uptake, separated by 60 min. During EX1 there was a significant accumulation of urate (from 0.16 +/- 0.02 to 0.27 +/- 0.03 micromol/kg d.w.) and allantoin (from 0.39 +/- 0.05 to 0.69 +/- 0.14 micromol/kg d.w.) in the muscle. An uptake of urate was observed in early recovery from EX1 (0-9 min: 486 +/- 136 micromol; p <.05). There was no exchange of total glutathione or cysteine over the muscle either during or after exercise, and muscle and plasma total glutathione remained unaltered (p <.05). The glycogen levels were lowered by 40% at the onset of EX2, yet the level of oxidative stress in EX1 and EX2 was similar as evidenced by a similar increase in muscle allantoin in both exercise bouts. The data suggest that urate is utilized as antioxidant in human skeletal muscle and that reactive oxygen species are formed in muscle during intense submaximal exercise. No net exchange of glutathione appears to occur over the muscle either at rest, during exercise or in recovery. Moreover, when an exhaustive exercise bout is repeated with lowered glycogen levels, the level of oxidative stress is not different than that of the first bout.

Caries and salivary status in young adults with type 1 diabetes.

The aim of this study was to evaluate the salivary status, prevalence of caries and the status of primary dentition, when primary teeth were exfoliated, in 41 patients, 18-24 years of age, with type 1 diabetes since childhood in comparison with age- and sex-matched non-diabetic controls. The blood glucose and glycosylated haemoglobin concentration (HbA1c), dosage of daily insulin and retinal fundus photography was recorded for the diabetic group. According to the concentration of HbA1c, the diabetic patients were divided into well and poorly controlled groups. The study was based on three intra-oral photos, dental examination including intra-oral radiographs, flow rate and buffering capacity of the saliva and amount of Streptococcus mutans and Lactobacilli. Retrospective data regarding the primary dentition was found in the dental files of each patient, and are based on the last registration for respective tooth before exfoliation. The patients with type 1 diabetes, without any relationship to metabolic control, displayed more initial buccal caries compared to healthy controls (p<0.01). No significant differences concerning the status of saliva (neither flow rate, buffering capacity nor amount of Streptococcus mutans and Lactobacilli), manifest caries or the status of the primary dentition were seen. We conclude that initial, but not manifest caries seems to be overrepresented in young adults with type 1 diabetes. These patients, thus, need more intense efforts regarding dental health care to prevent the development from initial to manifest caries.

Immunological changes in human skeletal muscle and blood after eccentric exercise and multiple biopsies.

1. A role of the immune system in muscular adaptation to physical exercise has been suggested but data from controlled human studies are scarce. The present study investigated immunological events in human blood and skeletal muscle by immunohistochemistry and flow cytometry after eccentric cycling exercise and multiple biopsies. 2. Immunohistochemical detection of neutrophil- (CD11b, CD15), macrophage- (CD163), satellite cell- (CD56) and IL-1beta-specific antigens increased similarly in human skeletal muscle after eccentric cycling exercise together with multiple muscle biopsies, or multiple biopsies only. 3. Changes in immunological variables in blood and muscle were related, and monocytes and natural killer (NK) cells appeared to have governing functions over immunological events in human skeletal muscle. 4. Delayed onset muscle soreness, serum creatine kinase activity and C-reactive protein concentration were not related to leukocyte infiltration in human skeletal muscle. 5. Eccentric cycling and/or muscle biopsies did not result in T cell infiltration in human skeletal muscle. Modes of stress other than eccentric cycling should therefore be evaluated as a myositis model in human. 6. Based on results from the present study, and in the light of previously published data, it appears plausible that muscular adaptation to physical exercise occurs without preceding muscle inflammation. Nevertheless, leukocytes seem important for repair, regeneration and adaptation of human skeletal muscle.

Effect of Q10 supplementation on tissue Q10 levels and adenine nucleotide catabolism during high-intensity exercise.

The aim of the present study was to investigate the concentration of ubiquinone-10 (Q10), at rest, in human skeletal muscle and blood plasma before and after a period of high-intensity training with or without Q10 supplementation. Another aim was to explore whether adenine nucleotide catabolism, lipid peroxidation, and mitochondrial function were affected by Q10 treatment. Seventeen young healthy men were assigned to either a control (placebo) or Q10-supplementation (120 mg/day) group. Q10 supplementation resulted in a significantly higher plasma Q10/total cholesterol level on Days 11 and 20 compared with Day 1. There was no significant change in the concentration of Q10 in skeletal muscle or in isolated skeletal muscle mitochondria in either group. Plasma hypoxanthine and uric acid concentrations increased markedly after each exercise test session in both groups. After the training period, the postexercise increase in plasma hypoxanthine was markedly reduced in both groups, but the response was partially reversed after the recovery period. It was concluded that Q10 supplementation increases the concentration of Q10 in plasma but not in skeletal muscle.

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.

Urate uptake and lowered ATP levels in human muscle after high-intensity intermittent exercise.

The exchange of purines in exercised and rested muscle and their relation to muscle ATP levels after intense intermittent exercise were investigated. Seven subjects performed one-legged knee extensor exercise on the following two occasions: without (control; C) and with (high purines; HP) additional arm exercise. There was a greater net release of hypoxanthine by the exercised muscle during the recovery period in HP compared with C [185 +/- 44 vs. 101 +/- 30 (SE) mumol/kg muscle; P < 0.05]. During recovery, the arterial urate concentration was higher in HP compared with C (peak: 585 +/- 48 vs. 355 +/- 20 mumol/l; P < 0.05). The exercised but not the rested muscle extracted a marked amount of urate (330 mumol/kg muscle) from plasma in the HP trial. Muscle ATP levels after 90 min of recovery in HP were lower than at rest (24.3 +/- 0.6 vs. 20.1 +/- 1.1 mmol/kg dry wt). The present data suggest that a single session of long-term high-intensity intermittent exercise causes a significant release of purines from the muscle into blood, which contributes to a sustained lowered level of the muscle ATP concentration. Furthermore, intensely exercised muscle extracts urate when plasma urate is elevated, an event that may be of importance for the replenishment of oxidized muscle urate stores.

Effects of ubiquinone-10 supplementation and high intensity training on physical performance in humans.

This study investigated the effects of oral supplementation with ubiquinone-10 (Q10) (n = 9) compared with a placebo (n = 9) on aerobic and anaerobic physical performance over 22 days of supplementation. The supplementation period included 5 days of high intensity anaerobic training between days 11 and 14. The results demonstrated, that on an anaerobic (10 x 10 s) cycling test, the placebo group showed a significantly greater improvement than the Q10-group after a supplementation and training period (P < 0.001). Further, the Q10 group had a significantly lower increase in total work performed during the seven training sessions (15 x 10 s) compared with the placebo group (P < 0.001). There was a significant increase in maximal blood lactate accumulation during cycling in the both groups, when compared with levels before the training and recovery period. There was no significant difference between the groups, either in VO2max determined during running, or in submaximal and peak VO2, Rate of Perceived Exertion, respiratory quotient, blood lactate concentration or heart rate determined during submaximal and maximal cycling. Although insignificant (P = 0.1-0.3), there was evidence of higher submaximal VO2 (55-80% of VO2peak) during cycling in the Q10-group compared with the placebo group after training and recovery. It is concluded that with high intensity anaerobic training, there was a significantly greater increase in anaerobic performance in the placebo group compared with the Q10 group. The results suggest less increase in physical performance with Q10 supplement and high intensity anaerobic training, compared with placebo.

Xanthine oxidase in human skeletal muscle following eccentric exercise: a role in inflammation.

1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised and the control leg, together with venous blood samples, were obtained prior to exercise and at 45 min, 24, 48 and 96 h after exercise. The time courses of xanthine oxidase immunoreactivity and indicators of muscle damage and inflammation were examined. 2. The number of xanthine oxidase structures observed by immunohistological methods in the exercised muscle was up to eightfold higher than control from day 1 to day 4 after exercise (P < 0.05). The increase was attributed to an enhanced expression of xanthine oxidase in microvascular endothelial cells and an invasion of leucocytes containing xanthine oxidase. 3. The concentration of plasma interleukin-6 was significantly higher 90 min after exercise than before exercise (P < 0.05) and remained higher than pre-exercise levels throughout the 4 days. On day 4 the plasma creatine kinase activity was approximately 150-fold higher (P < 0.05) than resting levels. 4. Despite the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase is associated with secondary inflammatory processes. The increase in xanthine oxidase in the muscle occurs mainly in microvascular endothelial cells, but occurs also via infiltrating leucocytes containing xanthine oxidase. A role for leucocytes in xanthine oxidase induction in endothelium is proposed.

Periodontal health in adopted children of Asian origin living in Sweden.

In the present study the periodontal condition of a group of adopted 6-17 year-old children of Asian origin living in Sweden was compared with that of age- and sex matched Sweden children. Thirty-one Asian children and 31 Swedish children participated. Data on general health for all the children and on age at arrival for the Asian children was collected by interview. A clinical examination included recording of presence of plaque, supragingival calculus, bleeding on probing, probing depth, and caries. Radiographs were used to determine marginal bone loss (distance between the cemento-enamel junction and the marginal bone level > 2 mm), proximal calculus, and proximal caries. In addition, previously taken and filed radiographs of the primary dentition of the older children and current radiographs of the younger children with primary teeth were analysed to determine the prevalence of bone loss and calculus. The children of Asian origin showed a significantly higher number of surfaces with plaque and bleeding on probing. No significant differences were noted in the number of individuals with probing depths > or = 4 mm, supragingival calculus, or radiographic calculus. Three of the Asian and none of the Swedish children displayed radiographic bone loss. The retrospective analysis of all available radiographs from the primary dentition showed that 9 of 29 (31%) Asian children and 2 of 29 (7%) Swedish children had experienced bone loss in primary teeth.

Effect of sprint cycle training on activities of antioxidant enzymes in human skeletal muscle.

The effect of intermittent sprint cycle training on the level of muscle antioxidant enzyme protection was investigated. Resting muscle biopsies, obtained before and after 6 wk of training and 3, 24, and 72 h after the final session of an additional 1 wk of more frequent training, were analyzed for activities of the antioxidant enzymes glutathione peroxidase (GPX), glutathione reductase (GR), and superoxide dismutase (SOD). Activities of several muscle metabolic enzymes were determined to assess the effectiveness of the training. After the first 6-wk training period, no change in GPX, GR, or SOD was observed, but after the 7th week of training there was an increase in GPX from 120 +/- 12 (SE) to 164 +/- 24 mumol.min-1.g dry wt-1 (P < 0.05) and in GR from 10.8 +/- 0.8 to 16.8 +/- 2.4 mumol.min-1.g dry wt-1 (P < 0.05). There was no significant change in SOD. Sprint cycle training induced a significant (P < 0.05) elevation in the activity of phosphofructokinase and creatine kinase, implying an enhanced anaerobic capacity in the trained muscle. The present study demonstrates that intermittent sprint cycle training that induces an enhanced capacity for anaerobic energy generation also improves the level of antioxidant protection in the muscle.

Comparison of blood lactate concentrations obtained during incremental and constant intensity exercise.

Differences in blood lactate concentrations obtained during step-wise incremental and constant running exercise at the same intensities were investigated. In addition, the effect of endurance running at a constant intensity obtained by three different incremental modes (OBLA-4, 6 or 8 min) on the blood lactate concentration were studied. Eight firemen and six marathon runners performed: 1) three step-wise incremental running (IR) treadmill tests, each consisting of either 5 x 4, 5 x 6 or 5 x 8 min, and, 2) six 50 min constant intensity running (CR) treadmill tests. Capillary hemolyzed blood was used for lactate determination. The blood lactate during the 5 x 4 min IR-test was 32% (p < 0.001) lower for the firemen and 22% (p < 0.001) lower for the marathon runners compared with the steady state concentration. These differences were diminished in both groups when the 5 x 8 min IR test was used. In the marathon group, constant intensity running at the OBLA intensities obtained by the 5 x 4, 5 x 6 and 5 x 8 min resulted in a lactate accumulation to a mean level of 8.1 mmol.I-1. Also, the marathon runners interrupted the exercise due to maximal perceived exertion after only 19 +/- 3, 26 +/- 4 and 30 +/- 6 min, respectively. In the firemen group, a majority of the subjects were able to complete the 50 min runs, despite a blood lactate accumulation to a mean level of 7.3 mmol.l-1 at the OBLA 5 x 4 and 5 x 6 min intensities. When OBLA 5 x 8 min intensity was performed in this groups, a steady state blood lactate concentration to a mean level of 5.3 mmol.l-1 occurred. It is concluded that step-wise incremental exercise with durations of 4 or 6 min will lead to a high risk of overestimating the maximal lactate steady state exercise intensity and the endurance running capacity.

Hypophosphatasia affecting the permanent dentition.

Reports on dental abnormalities in connection with hypophosphatasia almost exclusively describe changes in primary teeth. A 23-year-old man with hypophosphatasia, first diagnosed at the age of 8 months, is described; histologically and radiographically verified signs of the condition were present in the permanent dentition. The findings included a reduced level of the marginal alveolar bone supporting the upper central incisors, which had to be extracted. The molars displayed large coronal pulp chambers. Histologically, the upper incisors demonstrated abnormal root cementum, with areas of dentin resorption, as well as disturbances of the mineralization of the coronal dentin. The patient also had signs of abnormal root resorption of molars. The potential involvement of permanent teeth puts children with hypophosphatasia at risk of developing oral complications during adolescent and adult life.

Increased expression of xanthine oxidase and insulin-like growth factor I (IGF-I) immunoreactivity in skeletal muscle after strenuous exercise in humans.

The present study investigated the effect of 7 days of strenuous exercise on the quantity of xanthine oxidase and IGF-I in muscle. Fifteen male military trainees performed 1 week of terrain marching and warfare exercises. Muscle biopsies and blood samples were obtained prior to and after the week. After the week, the number of xanthine oxidase immunoreactive cells, identified as capillary endothelial cells and leucocytes, and the number of IGF-I immunoreactive cells, mainly vascular cells but also cells tentatively identified as satellite cells, were higher in the muscle (P < 0.05). Plasma creatine kinase activity was 650% higher after the week (P < 0.001) and the muscle content of hydroxyproline was elevated by 160% 2 months post-exercise (P < 0.05), both findings implying injury to the muscle. The present data provide a first observation of an elevated level of xanthine oxidase and IGF-I in human skeletal muscle after exercise. It is proposed that both substances increased as a result of cellular damage: xanthine oxidase because of the influence of immunomodulators, and IGF-I in association with regenerative processes. The increased expression of IGF-I in the muscle could, however, also reflect cellular growth in response to an elevated load on the muscle and the vascular bed.

Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation.

Seven male subjects performed repeated bouts of high-intensity exercise, on a cycle ergometer, before and after 6 d of creatine supplementation (20 g Cr H2O day-1). The exercise protocol consisted of five 6-s exercise periods performed at a fixed exercise intensity, interspersed with 30-s recovery periods (Part I), followed (40 s later) by one 10 s exercise period (Part II) where the ability to maintain power output was evaluated. Muscle biopsies were taken from m. vastus lateralis at rest, and immediately after (i) the fifth 6 s exercise period in Part I and (ii) the 10 s exercise period in Part II. In addition, a series of counter movement (CMJ) and squat (SJ) jumps were performed before and after the administration period. As a result of the creatine supplementation, total muscle creatine [creatine (Cr) + phosphocreatine (PCr)] concentration at rest increased from (mean +/- SEM) 128.7 (4.3) to 151.5 (5.5) mmol kg-1 dry wt (P < 0.05). This was accompanied by a 1.1 (0.5) kg increase in body mass (P < 0.05). After the fifth exercise bout in Part I of the exercise protocol, PCr concentration was higher [69.7 (2.3) vs. 45.6 (7.5) mmol kg-1 dry wt, P < 0.05], and muscle lactate was lower [26.2 (5.5) vs. 44.3 (9.9) mmol kg-1 dry wt, P < 0.05] after vs. before supplementation. In Part II, after creatinine supplementation, subjects were better able to maintain power output during the 10-s exercise period (P < 0.05). There was no change in jump performance as a result of the creatine supplementation (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal and systemic findings in children with marginal bone loss in the primary dentition.

In a previous population-based study of 3896 7-9-year-old children living in Sweden, it was found that 32 children (0.8%) exhibited radiographic, periodontal bone loss at > or = 2 proximal surfaces of their deciduous teeth. In the present study, 26 of the 32 children were subjected to additional oral and systemic health examination. 20 other children without any radiographic evidence of bone loss in their primary dentition served as referents. None of the cases or the referents were detected to have any systemic disease. The frequency of bleeding and suppuration on probing, radiographic proximal calculus and probing attachment loss was higher among the cases than the referents. Actinobacillus actinomycetemcomitants was found subgingivally in 14 of the cases but in none of the referents. 11 of 22 cases analysed for presence of serum antibodies against A. actinomycetemcomitans leukotoxin were sero-positive compared to none of 7 referents available for analysis. Evaluation of the data from each child revealed wide variations in clinical parameters among the children in the case group. In this group, there were children with deep probing depths, probing attachment loss, suppuration on probing, proximal calculus and presence of subgingival A. actinomycetemcomitans, indicating current periodontitis. However, in the case group there were also children without positive signs of inflammatory disease, similar to the children in the reference group. In fact, the findings suggest that less than half of the number of individuals with > or = 2 proximal sites with bone loss had current periodontitis.

Compliance in use of electric toothbrushes.

This study investigates the frequency of use of electric toothbrushes in relation to time of possession and social background variables. A questionnaire was sent to 129 patients who had acquired an electric toothbrush within 36 months. They were patients at the Department of Clinical Periodontology and at general dental clinics in Orebro. Response rate was 96%. The brush was used daily by 62%, whereas 3% had ceased to use them. Frequency of use and encountered problems were related only for those who had had the brush for 3 years or more. Logistic regression on the frequency of use with the variables age, gender, marital status, education, time of possession, and received instruction showed no associations except in two cases. For patients at general dental clinics, only brush type, and for patients at the department, only encountered problems had explanatory value. The conclusion is that compliance level was high and unrelated to social factors.

Periodontal conditions in Vietnamese immigrant children in Sweden.

The aim of the present study was to compare the periodontal health in Vietnamese immigrant children in Sweden with that of native Swedish children. The study groups consisted of 42 6-17-year-old Vietnamese children and 42 age- and sex-matched Swedish children. Information on systemic health was obtained by interview. Clinical examination included recordings of dental plaque, supragingival calculus, bleeding on probing, probing depth, clinical attachment loss and caries. Radiographs were evaluated for presence of marginal bone loss, proximal calculus and proximal caries. In addition, previously obtained and filed radiographs were used as a supplement in order to evaluate if the children at any time point during the ages 4-11 years had experienced proximal calculus or bone loss in the primary dentition. The Vietnamese children showed significantly higher number of sites with bleeding on probing and with probing depths > or = 4 mm. Radiographic calculus was found in 55% of the Vietnamese and in 2% of the Swedish children. 5 Vietnamese children and 1 Swedish child showed periodontal bone loss at the time of examination. In all children except 1, the bone loss was confined to primary teeth. The retrospective analysis of available radiographs from the primary dentition showed that 28% of the Vietnamese children and 5% of the Swedish children had experienced bone loss in their primary teeth during the ages 4-11 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced oxygen availability during high intensity intermittent exercise impairs performance.

This study examined the influence of reduced oxygen availability on the ability to perform repeated bouts of high intensity exercise on a cycle ergometer. Seven male physical education students performed 10 exercise bouts (of 6 s each), interspersed with 30-s recovery periods, under hypoxic and normoxic conditions. The hypoxic condition was carried out in a low pressure chamber at 526 mmHg. Subjects were instructed to try to maintain a target pedalling speed of 140 rev min-1 during each exercise period. The mean power output of the first exercise bout was approximately 950 W. In both experimental conditions, all subjects were able to maintain the target speed for the first 3 s of each of the 10 exercise bouts. During the last 3-s interval of each exercise period the target speed was not maintained in both conditions over the 10 sprints. However, the reduction was greater in the hypoxic condition (P < 0.05). Post-exercise blood lactate accumulation was higher with hypoxia [10.3 (0.7) vs. 8.5 (0.8) mmol l-1, P < 0.05]. Oxygen uptake, measured during the exercise and recovery periods of sprints 6-9, was lower in the hypoxic condition [3.03 (0.2) vs. 3.19 (0.2) 1 min-1, P < 0.05]. These results indicate that a reduction in oxygen availability during high intensity intermittent exercise results in a higher accumulation of blood lactate and a lower oxygen uptake. The ability to maintain a high power output is impaired.