Neurofibroma of the oral cavity

Neurofibromata are uncommon tumours of the oral cavity, and are seen either as solitary lesions or as part of the generalised syndrome of neurofibromatosis. A review of the literature is presented together with a case report of a solitary neurofibroma.

Surgical division of right and left free wall accessory atrioventricular electrical connections in a child with incessant supraventricular tachycardia

A child with Wolff-Parkinson-White syndrome developed incessant supraventricular tachycardia refractory to medical therapy and countershocks. Supraventricular tachycardias incorporating both right and left free wall accessory atrioventricular electrical connections were demonstrated. The more frequent, broad complex tachycardia utilised both the accessory connections and was independent of the atrioventricular node. The less frequent, narrow complex tachycardia utilised the atrioventricular node for anterograde conduction and the left sided accessory connection for retrograde conduction. Surgical division of the accessory connections restored normal sinus rhythm and eliminated supraventricular tachycardia.

Management of heat exhaustion in Sydney's the Sun City-to-Surf run runners

Heat exhaustion (collapse with rectal temperature of, or higher than 38 degrees C) is the most common major medical complication of fun runs and is caused by dehydration and impaired heat loss with, or without, hypoglycaemia. All patients with heat exhaustion after the City-to-Surf runs from 1977 to 1979 were managed in a medical centre established at the finish of the course. Several methods of management of heat exhaustion are evaluated. Patients were allocated retrospectively to four primary treatment groups: (i) treated with ice-wet towels only; (ii) treated with ice-wet towels and intravenously administered fluids; (iii) treated with intravenously administered fluids and ice-cold packs applied to the neck, axillae, and groins; and (iv) treated with intravenously administered fluids only. There was no death or prolonged morbidity in any treatment group. In Group 1 (n=11), the mean initial rectal temperature was 40.2 +/- 1.5 degrees C. There were insufficient data to assess the mean time taken for the temperature to fall to 38 degrees C. In Group 2(n=16), the mean initial rectal temperature was higher than 40.9 +/- 1.1 degrees C. In three patients, the temperature failed to fall to 38 degrees C within 90 minutes. For the remainder, the mean time taken for the temperature to fall to 38 degrees C was 30 minutes. In Group 3 (n=16), the mean initial rectum temperature was higher than 41.2 +/- 1.0 degrees C. One patient, who had been febrile immediately before the run, was discharged with a temperature of 38.8 degrees C. For the remainder, the mean time taken for the temperature to fall to 38 degrees C was 36 +/- 10 minutes. In Group 4 (n=13), the mean initial rectal temperature was 39.6 +/- 1.1 degrees C and the mean time taken for the temperature to fall to 38 degrees C was 21 +/- 16 minutes. Heat exhaustion in fun-run casualties may be safely and effectively treated by rapid intravenous infusion of fluids with, or without, application of cold packs to the neck, axillae, and groins. The application of ice-wet towels is contraindicated.

Reducing the hazards in Sydney's the Sun City-to-Surf runs, 1971 to 1979

The hazards experienced by fun runners in Sydney's The Sun City-to-Surf run are principally physical, environmental and medical. The organizers of the event, advised by a representative of the Australian Sports Medicine Federation (N.S.W.), have progressively increased the implementation of the recommendations which were made after the inaugural run in 1971 in the areas of improved organization, competitor education, medical support, recording of competitor data, and conducting the event in cool weather. To ensure the maximum safety of the runners, the number of whom has increased from approximately 1650 in 1971 to 16200 in 1979, additional measurees have been taken. These were (i) the introduction of "spotters" with experience in sports medicine to identify and advise exhausted runners before they collapse; (ii) staffing the run's medical centre with medical and nursing specialists in intensive care; (iii) improved management of heat exhaustion; and (iv) conducting education seminars after the run to make recommendations for improving subsequent events. Since 1971, there has been a progressive reduction in the number of casualties. The incidence of casualties treated in the medical centre fell from 1.76% in 1971 to 0.1% in 1979; and the incidence of those requiring further treatment in hospital fell from 0.42% in 1971 to 0.01% in 1979. None of the participants had suffered severe complications of heat exhaustion. Improvements in the management of heat exhaustion (the most common cause of collapse) which made the use of iced water (hiterto traditional method of cooling casualties with hyperthermia) unnecessary have reduced the risk of using electrical equipment in wet surroundings. The over-all reduction in the incidence and morbidity of collapse casualties is due to a combination of factors. These factors and possibilities of further reduction of hazards are discussed.

Biochemical and haematological changes in Sydney's the Sun City-to-Surf fun runners

Before this study was undertaken, biochemical and haematological changes in collapsed fun runners have been interpreted only by comparison with changes observed in trained marathon runners, or by comparison with normal subjects. This study was undertaken to establish the pattern of biochemical and haematological changes to be expected in non-collapsed fun runners as a result of competition, and to use this pattern as the basis for comparison with changes observed in collapsed fun runners after similar competition. Forty-three fun runners (28 males, 15 females) who competed in the 1978 City-to-Surf run volunteered as non-collapsed "controls", while 10 runners (nine males, one female) who collapsed during the 1978 City-to-Surf run became "casualties" for comparison. Blood for detailed analysis was collected from the controls two weeks before the 1978 City-to-Surf run, immediately after the run and one month later; blood from the casualties was collected immediately after the run, and one month later. As a result of competition, three patterns of changes were observed, namely, haemoconcentration; tissue damage and altered organ system function; and alteration in carbohydrate metabolism. More intense tissue damage probably accounts for disproportionate changes of some variables in male controls compared with female controls, and in casualties compared with controls. Casualties differed most from controls in degree fo depression of serum bicarbonate levels, and degree of elevation of blood urea nitrogen, serum creatinine, uric acid and bilirubin levels. A wide scatter of blood sugar levels immediately after run both in controls and in casualties reflects the stress of prolonged exertion.

Theophylline half-life in infants and young children

Pharmacokinetics of theophylline elimination were studied in a 54-child population. Subjects' ages ranged from three months to six years. The mean half life was 4.92 hours, with S.D. +/- 1.88 hours. This is at variance with previous reports. Ages and half lives were compared and there were no correlations in this young age group.

The effect of soil water on root production of peach trees in summer

The effect of soil water supply on peach root production in summer was studied in the Goulburn Valley area of northern Victoria. Under commercial irrigation practice roots do not grow in summer. Field experiments showed that when the soil was kept moist by frequent irrigation (every 3–4 days), the concentration of roots in the surface soil nearly doubled in a single season. Furthermore, observation through glass plates showed that this enhanced root growth occurred throughout summer. When roots were kept inactive in dry soil until midsummer and thereafter irrigated frequently, they immediately responded and grew rapidly. The increased root growth did not impair fruit production. In a glasshouse experiment, with glass-fronted chambers, a relationship between root elongation, root concentration and the drying rate of the soil was found. Each experiment supported the hypothesis that soil drying rate determines the growth of roots in the surface soil. Where there was a high concentration of roots, a low irrigation frequency, and high transpiration, the rate of soil drying was rapid and roots grew slowly. It is suggested that manipulation of root growth by regulation of soil water supply may be an important method of studying root-top interactions.