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Biomedical subjects

B Sjödin

Publications and source records attributed to B Sjödin.

At least 19 recordsLinked to original sources
PubMed1996

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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1995

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.

Aggregatibacter actinomycetemcomitans↗
PubMed1995

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)

Adenosine Triphosphate↗
PubMed1995

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.

Age Factors↗
PubMed1995

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)

Adolescent↗
PubMed1994

The validity and accuracy of blood lactate measurements for prediction of maximal endurance running capacity. Dependency of analyzed blood media in combination with different designs of the exercise test.

The effect of using different blood lactate sampling sites in combination with different exercise test designs on the validity and accuracy for prediction of maximal endurance running velocity was investigated. Ten aerobically all-round trained firemen and nine aerobically endurance trained long-distance runners performed six differently designed treadmill running blood lactate accumulation tests. Each test consisted of five consecutive running periods on a treadmill of either 4, 6 or 8 min duration, with a mean increase in running velocity between each period of either 0.25 or 0.5 m.s-1. The corresponding treadmill running velocity to a lactate concentration of 4.0 mmol.l-1 in capillary and venous hemolysed blood and plasma for each running velocity. The mean running velocity from a maximal 12 km run for the firemen and a maximal 21 km run for the runners served as the reference of maximal endurance running velocity. There were both significant (p < 0.001) and similar relationships (r = 0.86-0.94) and no difference in mean prediction error between the predicted and measured maximal endurance running velocities with all tested protocols. However, there was a high risk of making both over- and underestimations (5% to -4%). The lowest risk of making an inaccurate prediction was found when a running duration of 8 min for each running period was used in combination with an increase in running velocity of 0.25 m.s-1, and the lactate measurements were performed in hemolysed capillary blood.

Adult↗
PubMed1994

Body-mass-modified running economy and step length in elite male middle- and long-distance runners.

To minimize the influence of body mass on oxygen uptake (VO2) during running, submaximal and maximal VO2 should preferentially be expressed as ml.kg-0.75.min-1. In this study, the levels of such body-mass-modified running economy were investigated at different velocities in elite runners and related to step lengths and anthropometric measures. Twenty-six Swedish National Team middle- and long-distance runners performed submaximal (4 velocities) and maximal treadmill tests. In 17 runners repeated (2-4) tests were performed within 6 months. The maximal oxygen uptake (VO2max; 214 vs 202 ml.kg-0.75.min-1) and running velocity at 4 mmol.l-1 blood lactate were higher in the long- (n = 12) than in the middle-distance group (n = 14). The oxygen uptake at 15 km.h-1 (VO2 15) was lower (129 vs 138 ml.kg-0.75.min-1, p < 0.01) and the VO2/velocity slope higher in the long-distance runners, with similar VO2 18 in the two groups. Step lengths at 18 (168 vs 173 cm) and 15 km.h-1 did not differ significantly between the groups, but the increase in step length per km.h-1 velocity raise was greater in the middle-distance runners. Step lengths at these velocities were positively related to body mass and stature, negatively to relative leg length. Stature and leg length were greater in runners displaying low VO2 15, whereas no corresponding difference was seen for VO2 18. The figures for running economy at 15 and 18 km.h-1 were poorly related to the concomitantly determined step lengths at the respective velocities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Marginal bone loss in the primary dentition. A survey of 7-9-year-old children in Sweden.

The present study was designed to determine the prevalence of bone loss in the primary dentition of children. Radiographs from children aged 7-9 were collected from 25 out of a total of 26 Public Dental Clinics in the County of Orebro, Sweden. These radiographs, representing 36.0%, 50.3% and 48.7% of all 7-, 8- and 9-year-old children (n = 8666) living in the districts of the participating clinics, constituted a primary sample. In addition, the 9-year-olds were subjected to a more comprehensive sampling procedure to obtain a more complete sample (sample of 9-year-olds), resulting in a group of 2017 children (71.9%). The radiographs were evaluated with respect to presence of marginal bone loss (CEJ-MBL: distance between the cemento-enamel junction and the marginal bone level > 2 mm), proximal calculus and number of decayed and filled proximal surfaces (dfsp) in the posterior areas of the primary dentition. In the primary sample, the prevalence of bone loss for > or = 1 proximal surfaces of the primary dentition in the 7-, 8- and 9-year-old children was 2.0%, 3.1% and 4.5%, respectively. The corresponding figures for proximal calculus were 2.5%, 3.1% and 4.2%. Mean number of dfsp amounted to 2.3, 2.5 and 3.0. The prevalences of bone loss and proximal calculus as well as the mean number of dfsp in the sample of 9-year-olds corresponded to the findings for the 9-year-old children in the primary sample.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗
PubMed1994

AMP deaminase in skeletal muscle of healthy males quantitatively determined by new assay.

A new, sensitive assay for the quantitative determination of AMP deaminase activity in human skeletal muscle is presented. The method is based on the determination of the direct product of the AMP deaminase reaction, the formed IMP, by high performance liquid chromatography (HPLC). In order to evaluate the relationship between AMP deaminase activity on the one hand and the contractile and metabolic characteristics of the muscle and the physical performance on the other, muscle biopsies were taken from 20 male subjects. The subjects also performed a 30 s sprint test on a cycle ergometer. The inter-individual variation in AMP deaminase activity was large, ranging from 5.4 to 27.4 microkat g-1 dry muscle. AMP deaminase was positively correlated with phosphofructokinase (PFK), the marker of the glycolytic capacity of the muscle, but there was no correlation with enzymes of oxidative metabolism, such as 3-hydroxyacyl-CoA dehydrogenase and citrate synthase, or with the activity of myokinase and lactate dehydrogenase. There was no significant correlation between AMP deaminase activity and the proportion of the different muscle fibre types. A weak positive correlation was found between the sprint performance and the AMP deaminase activity. In conclusion, the HPLC assay was found to be a fast, sensitive and reliable method for the quantitative determination of AMP deaminase activity in muscle. A direct relationship between AMP deaminase activity on the one hand and glycolytic capacity and sprint performance on the other was found. However, no relationship to oxidative capacity or contractile properties was found.

AMP Deaminase↗
PubMed1994

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.

Adenosine Triphosphate↗
PubMed1994

Exchange of purines in human liver and skeletal muscle with short-term exhaustive exercise.

The exchange of purines in liver and active skeletal muscle with short-term exhaustive exercise was investigated. Eight male subjects performed two similar 10-min bouts of exhaustive supine cycling, separated by 75 min of rest. Immediately after termination of the second bout, a tourniquet was applied to the upper part of the thigh for 10 min. After the first bout, the arterial concentration of hypoxanthine and uric acid increased from 4.1 +/- 0.3 (SE) to a peak value of 36.3 +/- 7.9 mumol/l (P < 0.05) and from 335 +/- 23 to a peak value of 421 +/- 28 mumol/l (P < 0.05), respectively. There was a net release of hypoxanthine from the muscle at 12 and 45 min postexercise and an uptake of hypoxanthine and inosine in the liver at 7 and 42 min postexercise. Uric acid was released from the liver at 7 and 42 min after exercise. Before the second exercise bout and at 2 and 10 min after the release of the tourniquet, there was a significant net uptake of uric acid by the muscle. The present study demonstrates that, after strenuous short-term exercise, the main source of plasma hypoxanthine is the muscle, with no net contribution of this purine from the liver. Hypoxanthine in the blood is taken up by the liver where most of it is converted to uric acid. After exercise and a short period of ischemia, uric acid is taken up by the muscle.

Adult↗
PubMed1993

Marginal bone loss in the primary dentition of patients with juvenile periodontitis.

118 patients with juvenile periodontitis (JP), diagnosed when the patients were 13-19 years old, were studied retrospectively with respect to radiographic marginal bone loss in the primary dentition, experienced when the patients were 5-12 years old. 168 other 13-19 year old patients without any signs of bone loss in the permanent teeth were used as a reference group. The JP patients were classified into 2 groups according to the number of sites with bone loss in the permanent dentition: JP group I having 1 site with bone loss (n = 45) and JP group II having > or = 2 sites with bone loss (n = 73). It was found that 35 patients (52%) of JP group II displayed 1 or more sites with bone loss in the primary dentition during the age of 5-12 years. The corresponding numbers for JP group I and the reference group were 9 (20%) and 8 (5%) respectively. These findings indicate that juvenile periodontitis, at least in some individuals, may have its onset already in the primary dentition.

Adolescent↗