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Biomedical subjects

J Ekstrand

Publications and source records attributed to J Ekstrand.

160 records · Page 9Linked to original sources
PubMed1979

Renal function and fluoride formation and excretion during enflurane anaesthesia.

Central circulation, renal function, and fluoride formation and excretion were studied in nine patients during enflurane anaesthesia and surgery. Cardiac output and mean systemic arterial pressure remained unchanged compared with preoperative control values. During anaesthesia and surgery, urine flow rate, inulin clearance, PAH clearance and fractional sodium excretion were 60, 65, 55, and 45% of control values, respectively. Mean peak plasma level of fluoride was 20.0 microM. It was reached 4 hours after termination of anaesthesia. Fluoride clearance (CF) decreased from 23.9 ml . min-1 to 2.7 ml . min-1 during anaesthesia. Postoperative, CF increased to 41.6 and 76.0 ml . min-1, respectively, during two consecutive measurement periods. There was no correlation between plasma fluoride levels and depression of any renal function variable.

Adult↗
PubMed1979

Fluoride kinetics and renal function during enflurane anaesthesia.

Renal function, fluoride formation and excretion were studied during and after enflurane anaesthesia in seven patients. During anaesthesia, urine flow rate, inulin clearance, PAH clearance and fractional sodium excretion were 13, 78, 65 and 49% of control values, respectively. Renal function was promptly restored postoperatively. Enflurane was metabolized to inorganic fluoride with a mean maximal serum level of 17.4 +/- 3.3 microM. Fractional fluoride excretion decreased during anaesthesia to 35% of the control value. Postoperatively, there was a highly significant correlation between the increase in fractional fluoride excretion and the rise in urinary pH during two consecutive 3-hour periods. It is suggested that tubular reabsorption of fluoride is inversely related to tubular fluid pH and that fluoride is reabsorbed by non-ionic diffusion.

Adult↗
PubMed1978

Fluoride bioavailability after intravenous and oral administration: importance of renal clearance and urine flow.

Fluoride (3 mg) was administered as a continous intravenous infusion during 30 min to 6 healthy subjects. Plasma concentrations and urinary excretion of fluoride in these experiments were compared with those obtained following oral administration of 2.82 mg, 4.50 mg, 5.64 mg, and 9.40 mg in the form of tablets and capsules. There were large day-to-day variations in the renal clearance of fluoride. This was shown to be due to differences in the urinary flow, an increase in flow causing an increase in renal clearance. The mean value of renal clearance from all experiments was 66.2 +/- 27.8 (SD; n = 16) ml/min. The extrarenal clearance, suggested to represent mainly the clearance to the bone pool, showed less interindividual variation: mean 110.3 +/- 32.3 (SD; n = 6) ml/min; the fraction remaining in the bone pool was highly consistent: 0.579 +/- 0.049 (SD; n = 6). When apparrent bioavailability was calculated from plasma and from urinary data, there was a great intra- and intersubject variation, as well as poor agreement between the two methods of calculations. This was found to be due to the day-to-day variation in renal clearance, which, in turn, varied with urinary flow. By use of equations that corrected for these variations, it was found that the bioavailability of sodium fluoride tablets is approximately 100%.

Administration, Oral↗
PubMed1977

Pharmacokinetics of fluoride in man after single and multiple oral doses.

The doses of fluoride (F) recommended in the literature for caries prevention and for the treatment of osteoporosis vary. This partly reflects inadequate knowledge of F pharmacokinetics. In the present study various single and multiple oral doses of F were given to eight volunteers, who had a strictly controlled F intake in the diet. The resulting plasma and parotid saliva concentrations as well as urinary output of F were measured. The plasma data fitted a two-compartment open model with a beta-slope half-life ranging between 2 and 9 h. Plasma clearance was 0.15+/-0.02 (SD) liter/kg/h. Data from the highest dose (10 mg) were fitted to both two- and three-compartment models, and there was no significant difference between them. Multiple doses of F 3.0 Or 4.5 mg yielded steady state concentrations ranging from 54 to 145 ng/ml. About 50 per cent of the given dose was recovered in the urine, which is indicative of considerable accumulation in the body. The saliva F/plasma F concentration ratio was 0.64 with a coefficient of variation of 5%.

Administration, Oral↗
PubMed1977

A micromethod for the determination of fluoride in blood plasma and saliva.

A simple and accurate technique for the determination of fluoride (F-) in capillary-sampled blood is presented. The method is based on the known addition-slope determination technique using the fluoride electrode. No calibration curve or calibration of the electrode is required. A standard deviation of 1.3-5.6% in the range 300-10 ng F/ml was given by 259 duplicate determinations on human plasma. Measurements of parotid saliva showed that it was possible to analayze fluoride concentrations as low as 4 ng F/ml with good reproducibility. The results also show that a 150 microliter sample is sufficient for fluoride determination with high accurary. This method can easily be used in clinical laboratory.

Electrodes↗
PubMed1977

Fluoride concentrations in saliva after single oral doses and their relation to plasma fluoride.

The saliva and plasma fluoride (F) concentrations following intake of different doses of fluoride tablets were studied in six subjects. There was a close relationship between saliva F and plasma F and the ratio was 0.64 +/- 0.01 (s.e.). The plasma half life of F was 4-16 h. This results indicate that saliva F may be a useful substitute for blood sampling in studies concerning the pharmacokinetics of fluoride.

Administration, Oral↗
PubMedDate not supplied

The frequency of muscle tightness and injuries in soccer players.

One hundred-eighty players in a male, senior soccer division were examined for past injuries, persisting symptoms from past injuries, and muscular tightness in the lower extremities. Soccer players were in general less flexible than a group of nonplayers of the same age (n = 86). No correlation was found between past injuries and existing muscle tightness. Sprains of the lower extremity, especially of knees and ankles, predominated among the injuries. Persistent instability symptoms were common sequels to knee and ankle injuries. It is proposed that intensive care of acute injuries will improve the late results.

Adolescent↗
PubMedDate not supplied

Incidence of soccer injuries and their relation to training and team success.

One hundred-eighty players in a male soccer senior division of 12 teams were observed prospectively for 1 year to study the risk of soccer injuries in relation to exposure and to establish the connection between training, injuries, and team success. Totally, more than 100 hours of practice were analyzed. All injuries were examined by the same orthopaedic surgeon. On the average, each team played 36 games and had 95 practice sessions with 66% attendance of selected players. A direct correlation was noted between team success and the amount of training. Teams with more than average training showed a diminishing number of injuries. A high practice-to-game ratio seems to be advantageous. One injury every third game and every ninth practice session was documented. For the individual player the incidence of injury was 7.6/1000 practice hours and 16.9/1000 game hours. The incidence of injury was higher at training camps. Correlation was noted between the design of the training and the incidence of injuries. The duration of warming up seemed adequate, but its content did not appear to be satisfactory from a clinical point of view. Redesign of the warm-up with more emphasis on flexibility and the addition of a cool-down is suggested to reduce injuries.

Adolescent↗
PubMedDate not supplied

Prevention of soccer injuries. Supervision by doctor and physiotherapist.

To study the efficacy of an injury prevention program in a randomized trial, 12 teams (180 players) in a male senior soccer division were followed up for 6 months. The 12 teams were allocated at random to two groups of six teams, one being given a prophylactic program and the other serving as control. The program was based on previous studies of injury mechanisms. It comprised (1) correction of training, (2) provision of optimum equipment; (3) prophylactic ankle taping; (4) controlled rehabilitation; (5) exclusion of players with grave knee instability; (6) information about the importance of disciplined play and the increased risk of injury at training camps; and (7) correction and supervision by doctor(s) and physiotherapist(s). The injuries in the test teams were 75% fewer than in the controls. The most common types of soccer injuries, sprains and strains to ankles and knees, were all significantly reduced. It is concluded that the proposed prophylactic program, including close supervision and correction by doctors and physiotherapists, significantly reduces soccer injuries.

Adolescent↗
PubMedDate not supplied

Effects of warming up, massage, and stretching on range of motion and muscle strength in the lower extremity.

The effects of general warming up, massage, and stretching on ranges of motion (ROM) and strength of quadriceps and hamstring muscles were measured in eight male volunteers. Thigh muscle strength was not influenced by the experimental procedures. Stretching resulted in a significantly increased range of hip flexion/extension, hip abduction, knee flexion, and ankle dorsiflexion; the effect was significantly greater than that obtained by massage and warming up separately or combined. Only ankle dorsiflexion was influenced by massage or warming up, whereas stretching affected all muscle groups tested. Stretching was, therefore, superior to the other methods tested for increasing flexibility in the lower extremity.

Biomechanical Phenomena↗
PubMedDate not supplied

The effect of a patella brace on performance in a knee extension strength test in patients with patellar pain.

The object of this study was to analyze the quadriceps muscle peak strength with the Cybex-II isokinetic dynamometer in patients with patellofemoral arthralgia with and without a patella brace. Twenty-four patients, 18 women and 6 men, were studied. All had patellofemoral arthralgia. The diagnosis was made on typical clinical findings, but was supplemented with arthroscopy in seven patients with pain also over the medial joint line. After a 2 week adaptation period with the brace, a Cybex-II test was done with and without the brace. The other leg was tested as control. Twenty-one patients (88%) improved their performance in the strength test with the brace (mean difference 13.7 +/- 9.1%). With the brace, 14 patients (58%) performed at 95% of their control leg or more compared to 6 (25%) without the brace. Patients under the age of 30 years had a better effect than patients over that age.

Adolescent↗
PubMedDate not supplied

Factors affecting stabilometry recordings of single limb stance.

Stabilometry is an objective method for the quantitative study of postural equilibrium and has previously been shown to correlate to functional instability of the ankle joint. Stabilometric recordings of 25 soccer players did not confirm existing theories that an ankle joint injury itself produces a functional instability. Stabilometric recordings of 38 soccer players with and without ankle taping did not show that taping influenced the stabilometric values. In 10 soccer players with functional instability, a significant improvement of stabilometric results and subjective "giving way" feelings were found after 6 weeks of coordination on an ankle disk.

Acute Disease↗
PubMedDate not supplied

Muscle rehabilitation after arthroscopic meniscectomy with or without tourniquet control. A preliminary randomized study.

Nineteen patients with isolated meniscus lesions were randomly assigned to operation with or without tourniquet. All patients underwent arthroscopic meniscectomy. Measurements of CK (creatinin-kinase), CK-B (isoenzymes MB of creatinin-kinase), LD (lactate dehydrogenase), ASAT (aspartate aminotransferase), and ALAT (alanine aminotransferase) were performed preoperatively and postoperatively over 6 days. The muscle torque was measured on a Cybex II isokinetic dynamometer preoperatively, 1 week and 4 weeks postoperatively. The mean CK level rose significantly in both groups, but did not pass the upper normal serum level. There was no effect on the other muscle enzymes. Quadriceps torque was significantly lowered in both groups 1 week after operation. Four weeks postoperatively, it was still lowered in the nontourniquet group, which also had a slower increase in torque between weeks 1 and 4 than the tourniquet groups. There was no effect from the operation on isometric or hamstrings torque. The slight rise in CK was similar to that seen after hard physical exercise. The decrease in muscle torque was, therefore, mostly due to pain inhibition. The slightly slower rehabilitation in the nontourniquet group may be caused by the technique of raising saline flow and pressure during the arthroscopy to control bleeding. This causes extravasation of fluid which may increase postoperative pain and stiffness.

Adult↗