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Biomedical subjects

J Leddy

Publications and source records attributed to J Leddy.

5 recordsLinked to original sources

A population based investigation of head injuries and symptoms of concussion of children and adolescents in schools.

OBJECTIVE: To examine the incidence of head injury and symptoms of concussion among children at school and to determine the relationship of age, gender, and cause to incidence rates. DESIGN: Incident reports involving head injury for schools in the Province of Ontario, Canada during the year 2000 were evaluated. PARTICIPANTS: The population base for the schools represented was 1 372 979 children aged 6 to 16. SETTING: 95% of schools in the province of Ontario, Canada participated in the injury reporting system. MAIN OUTCOME MEASURES: A head injury was defined as any injury to the head that came to the attention of a school official. Head injuries accompanied by symptoms of concussion became a secondary outcome measure. RESULTS: There were 11 068 unduplicated head injury reports for the year 2000 of which 1861 qualified as producing signs or symptoms of concussion. Young children were more likely to have a head injury than older children, but slightly less likely to experience concussive symptoms. The primary cause of injury to young children was falls. Older children were more likely to receive head injuries and symptoms of concussion from sports activities. CONCLUSIONS: Overall rate of injury (3.98 per 100 children) was consistent with previous studies using prospective injury reporting systems. Probability of a head injury with symptoms of concussion among schoolchildren was only 1.9% for boys and <1% for girls during the course of their school years. There is ample justification for prevention efforts in schools.

Accidental Falls↗

Dietary fats and immune status in athletes: clinical implications.

Athletes are competitive, train at very high levels with inadequate rest, consume too few calories, avoid fats, and may be at increased risk of infections. The immune system is sensitive to both fat intake and intense exercise, suggesting that athletes may have suppressed immune function. It has been reported that many athletes consume about 25% fewer calories than the estimated expenditure, leading to low intakes of some essential micronutrients and fats. Acute exercise has been shown to increase inflammatory and decrease antiinflammatory immune factors and may increase oxidant stress. Chronic exercise appears to improve immune competence. Lipids are powerful mediators of the immune system, and they may modulate the immunosuppressive effects of strenuous exercise. Studies have shown that a low-fat high-carbohydrate diet (15% fat, 65% CHO, 20% protein of total calories), typically eaten by athletes, increases inflammatory and decreases antiinflammatory immune factors, depresses antioxidants, and negatively affects blood lipoprotein ratios. Increasing total caloric intake by 25% to match energy expenditure and the dietary fat intake to 32% in athletes appears to reverse the negative effects on immune function and lipoprotein levels reported on a low-fat diet. Increasing the dietary fat intake of athletes to 42%, while maintaining caloric intake equal to expenditure, does not negatively affect immune competency or blood lipoproteins, whereas it improves endurance exercise performance at 60-80% of VO2max in cyclists, soldiers, and runners. There is no evidence that higher fat intakes (up to 42% of total calories), in calorically balanced diets, increase the risk of cancer, but studies are needed to determine whether the beneficial effects of higher fat diets in athletes reduce their rate of infections.

Antioxidants↗

Effect of a high or a low fat diet on cardiovascular risk factors in male and female runners.

Dietary fat may be associated with coronary heart disease (CHD). Studies suggest that restricting fat intake may compromise endurance performance and that increasing fat intake may improve endurance performance. We studied the effects of varying dietary fat intake on CHD risk factors in runners. Twelve male and 13 female runners increased fat from 16% to 30% of daily calories (4 wk each). Of this group, six males and six females increased fat to 42% of daily calories (4 wk). Physiological and lipoprotein risk factors were measured after each diet. Results were analyzed by repeated measures ANOVA. Increasing dietary fat from 16% to 42% of daily calories did not change adiposity, weight, heart rate, blood pressure, serum triglycerides, total cholesterol, LDL cholesterol. Apolipoprotein B, or the Apo A1/Apo B ratio. Compared with those eating higher fat, subjects eating 16% fat had lower HDL cholesterol (50 +/- 3 vs 62 +/- 3 mg.dl-1, P < 0.0001) and Apolipoprotein A1 (111 +/- 6 v. 134 +/- 6 mg/dl, P < 0.0005) and a higher TC/HDL-C ratio (4.05 +/- 0.27 vs 3.42 +/- 0.24, P < 0.0005). Runners who increased fat intake to 42% further raised HDL cholesterol (64 +/- 6 to 69 +/- 5 mg.dl-1, P < 0.04) without adversely affecting other lipoproteins. In conclusion, a 42% fat diet maintained favorable CHD risk factors in female and male runners whereas a 16% fat diet lowered Apo A1 and HDL-C and raised the TC/HDL-C ratio.

Apolipoproteins↗

Anti La(SSB) identifies a distinctive subgroup of systemic lupus erythematosus.

The relevance of antibodies for La(SSB) as a marker of a distinctive systemic lupus erythematosus (SLE) subset was studied in 185 lupus patients. Anti La was detected in 39 (21%) and was accompanied invariably by anti Ro. Clinically, anti La-positive patients were distinguished by a later age of disease onset, and a low frequency of lupus nephritis. In common with other anti Ro-positive patients they showed a high frequency of keratoconjunctivitis sicca. Anti La identified patients with higher titres of anti Ro antibodies and was significantly associated with HLA-DR3. Serological markers such as these are useful for identifying more homogeneous populations of SLE patients for studies of aetiology and pathogenesis.

Adult↗