Renal clearance of fluoride in children and adolescents

Renal function and fluoride excretion have been studied in 38 children. The children were divided into three groups according to their glomerular filtration rate: normal (92 to 136 mL/min/1.73 m2 of body surface area [BSA]), low (less than 92 mL/min/1.73 m2 BSA, and super-normal (greater than 136 mL/min/1.73 m2 BSA). Standard clearance technique with infusion of inulin and p-aminohippuric acid during water diuresis was used. Mean renal fluoride clearance was 45.0 +/- 9.8 (SD) mL/min in the group of children with normal glomerular filtration rates and 31.4 +/- 8.8 mL/min in the group with low glomerular filtration rates. This difference was statistically significant. There was a close linear relationship between renal fluoride clearance and glomerular filtration rate, urinary flow, and free water clearance. The fractional fluoride excretion did not differ between the groups. About 60% of the filtered fluoride was reabsorbed. No evidence for tubular secretion exceeding the reabsorption could be found. The results suggest that children have lower renal fluoride clearance rates than adults and indicate that a moderate impairment of the renal function could lead to increased retention of fluoride.

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.

Muscle strength and flexibility in different positions of soccer players

One-hundred eighty soccer players were tested for muscle strength in knee extension and knee flexion and for flexibility in the lower extremity. The strength measurements were done with a Cybex II isokinetic device (Lumex, Bay Shore, New York). The range of motion (ROM) was measured according to a method described by Ekstrand et al. (1982). The players were divided into groups according to their player position: goalkeepers, defenders, midfielders, and forwards. The results showed a significantly higher knee extensor torque in goalkeepers and defenders than in forwards (P less than 0.05). The knee flexion/knee extension ratio (H/Q ratio) was significantly higher for forwards compared to goalkeepers (P less than 0.001) and defenders (P less than 0.01). The goalkeepers were significantly more flexible than the other players in hip flexion (P less than 0.001), knee flexion (P less than 0.01), and ankle dorsiflexion (P less than 0.001).

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.

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.

The relationship between plasma fluoride, urinary excretion rate and urine fluoride concentration in man

The fluoride concentration in urine is commonly used for monitoring fluoride exposure, e.g., in aluminium plants. Hitherto this parameter does not seem to have been related to the actual fluoride concentration in plasma following fluoride exposure. In the present study the fluoride concentration in urine, the urinary excretion rate of fluoride and the fluoride concentration in plasma have been studied in five volunteers after intake of 10 mg of fluoride in the form of sodium fluoride (NaF) tablets. In pharmacokinetic analyses of the data calculation of the half-life of fluoride from plasma data and from the urinary excretion rate yielded almost identical results; 5.78 hours (plasma) and 5.11 hours (urine). It was found that plasma fluoride levels were correlated with the fluoride concentration in urine (r = .7532; n = 70), but even more with the urinary excretion rate of fluoride (r = .9651; n = 63). The data suggest that plasma fluoride levels or urinary excretion rates of fluoride may give a more correct picture of occupational fluoride exposure than fluoride concentrations in urine.

No effect of prolonged fluoride exposure on cytochrome P-450 and associated monooxygenases or on the level of polyamines in the rat

When exposing rats to drinking water containing 100 p.p.m. fluoride for 8 weeks, no effect could be detected in biochemical parameters of the liver, such as the concentrations of the polyamines putrescine, spermidine and spermine; the levels of microsomal protein and cytochrome P-450; or the activities of two associated monooxygenases, aryl hydrocarbon hydroxylase and ethylmorphine N-demethylase. Neither was there any increase in plasma glutamic-oxalacetic transaminase indicative of liver damage.

Renal excretion of fluoride during water diuresis and induced urinary pH-changes in man

Fluoride renal clearance (CF) was studied in young healthy subjects with standard clearance technique following administration of 3 mg F as a 30-min constant infusion. High urinary flow rates were induced and experiments were performed under both urinary alkaline and acidic conditions. The data showed that a high urinary flow resulted in maximum fluoride clearance. High water diuresis may therefore be an important part in the treatment of acute fluoride intoxication.

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.

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.

The avoidability of soccer injuries

One hundred eighty players in a male soccer division were followed prospectively for 1 year to assess etiologic factors in soccer injuries. Range of motion and muscle strength in the lower extremities were measured in a preseason test. All injuries during 1 year were examined by the same orthopaedic surgeon. 42% of the injuries were considered to be due to player factors, such as joint instability, muscle tightness, inadequate rehabilitation, or lack of training. Ankle sprains were commoner in players with previous ankle sprains or clinical instability. 35% of the moderate (absence from practice greater than 1 week, less than 1 month) or major (absence greater than 1 month) injuries were preceded by minor (absence less than 1 week) injuries, reflecting inadequate rehabilitation. Players sustaining knee sprains not due to collision had reduced muscle strength in the injured leg. No other strength differences between injured and uninjured players were found. 63% of players had tight muscles. Strains more commonly affected players with muscle tightness. 71% of the injuries proved to be explicable by and associated with player factors, equipment, playing ground, or rules.

Cyclic AMP in urine, kidney and liver following long-term administration of fluoride to rats

Rats were exposed to fluoride (F) for up to 8 weeks through the drinking water containing 100 p.p.m. F. Urine samples were regularly collected, together with tissue samples of liver and kidney at termination. All samples were assayed for cyclic AMP. No F-effect was found on liver or kidney levels of cyclic AMP. In the urine from the F-exposed rats there was an overall increase in the cyclic AMP concentration, but a decreased or unaffected 24 hrs urinary excretion of cyclic AMP. However, the F-exposed rats exhibited a considerably lower diuresis than the control animals. Because a significant negative correlation was found between diuresis and urinary concentration of cyclic AMP, the material was corrected to similarity in the mean diuresis between the two groups. Then no effect of F-exposure could be detected either in the urinary concentration or the daily excretion of cyclic AMP.

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.

Soccer injuries and their mechanisms: a prospective study

In order to study the incidence and mechanisms of injury in soccer and to recommend prophylactic measures, 180 players in a senior male soccer division were followed prospectively for 1 yr. Attendance records for games and practice sessions were kept, and all injuries were examined and treated by the same orthopaedic surgeon. One hundred twenty-four players incurred 256 injuries, mostly sprains and strains of the lower extremities. Of these, 62% were considered minor with ankle sprains being the most common (17%), while 11% were considered major with knee ligament sprains being the most frequent (32%). Overuse injuries were most frequent in the preseason training period. Traumatic leg injuries involved players with inadequate or no shin guards. Of the traumatic knee injuries, 11 of 18 (61%) occurred during a collision; non-contact knee injuries were frequently seen in those players with a history of knee injury and existing instability. Study of injury sequence disclosed that a minor injury was often followed within two months by a major one. In addition, with severe injuries incurred during fouls, the individual causing the penalty was injured. This prospective study suggested that those with knee instability and those allowed to resume play with poorly rehabilitated or clinically unhealed injuries are more apt to sustain further injury. Some injuries can be avoided by using better equipment and by observance of the rules.

Fluoride pharmacokinetics in the domestic pig

Plasma fluoride concentrations were studied in 11 pigs following single oral or intravenous doses of fluoride. The results showed a less-than-20% bioavailability of fluoride when administered with calcium-rich food. Pharmacokinetic analyses showed that the plasma half-life varied from 0.6 to 1.4 h, depending on diet and route of fluoride administration. These data are comparable to those reported for man, and thus illustrate the suitability of the pig for studies of effects of fluoride on hard tissues.

Renal clearance of fluoride in a steady state condition in man: influence of urinary flow and pH changes by diet

In order to study fluoride renal clearance, four subjects were given 3 mg fluoride as sodium fluoride tablets every 6 hrs for 60 hrs during two separate periods - during production of acid urine induced by a protein rich diet and during production of alkaline urine obtained by giving a vegetarian diet. Plasma and urine were collected every third hour for 72 hours during each experiment. In the protein rich diet period urinary pH was significantly lower than when the subjects were maintained on the vegetarian diet. Lower urinary output of fluoride during the protein rich diet experiment was recorded, however, the difference was not significant. Plasma fluoride at steady state was almost the same during both experiments. Renal fluoride clearance was significantly correlated to urinary pH in both types of experiments. When renal fluoride clearance was plotted versus urinary flow, the correlation was only significant during alkaline conditions. The average renal clearance was not significantly different between the two sets of experiments. It may be concluded, that pH and diuresis both influences fluoride renal clearance. Moreover, the results suggests that dietary components as such, influence renal clearance of fluoride in some way or another.

Lower extremity goniometric measurements: a study to determine their reliability

Two series of healthy men were measured for range of passive motion of hip flexion, hip extension, hip abduction, knee flexion, and ankle dorsiflexion with the knee extended and flexed. Hip abduction was measured with a specially constructed double protractor goniometer, and the other movements were gauged with a flexometer. In series A measurements were based upon a commonly used clinical method. The intratester interassay coefficient of variation in series A was 7.5 +/- 2.9%, which corresponded well with other reports. In series B posture and measuring procedures were rigidly standardized by better fixation and by identification and marking of anatomical landmarks. The interassay coefficient of variation in series B was reduced to 1.9 +/- 0.7%. Range of motion measurement was repeated accurately by the same tester with methods requiring careful measurement technique but no elaborate equipment.