The purpose of this study was to examine intratester and test-retest reliability using a hand-held dynamometer for the measurement of isometric muscle strength in 28 healthy children and children with Duchenne muscular dystrophy. The Dystrophic Group consisted of 14 children diagnosed with Duchenne muscular dystrophy, and the Healthy Group consisted of 14 age-matched children with no history of orthopedic or neuromuscular disorders. One physical therapist tested hip and knee extension, elbow flexion, and shoulder abduction in each child bilaterally. A two-way analysis of variance for repeated measures was used to analyze differences between measurements taken within and across the testing sessions. Pearson product-moment correlation coefficients were determined on mean values across the testing sessions for each variable. No significant differences (p greater than .05) between measurements taken within or across testing sessions were found in either the Dystrophic Group or the Healthy Group. Correlation coefficients for the Dystrophic Group ranged from .83 to .99 for the variables tested. Correlation coefficients for the Healthy Group ranged from .74 to .99. The results suggest that the hand-held dynamometer can be used as a reliable instrument in measuring the isometric strength of selected muscles in children.

No abstract

Anemia associated with vitamin A deficiency and increased liver iron has implicated vitamin A in the regulation of iron release from the liver. To study this relationship further, groups of weanling rats were fed diets as follows: low iron/low vitamin A, low iron/high vitamin A, normal iron/normal vitamin A, high iron/low vitamin A and high iron/high vitamin A. After 6 weeks the animals were killed, and blood and liver samples were taken for analyses of hemoglobin, hematocrit, red blood cell count, serum and liver vitamin A, serum and liver iron and total iron-binding capacity. Low dietary iron, but not low vitamin A intake, affected hemoglobin, hematocrit and red blood cell counts but not serum vitamin A levels. Mean serum vitamin A levels were not significantly lower in groups fed high dietary iron. High dietary iron was also associated with lower mean liver vitamin A levels; these differences were statistically significant only for the low vitamin A diet group. A high vitamin A intake was associated with a significantly lower mean hepatic iron level for the high dietary iron intake group. These data support the hypothesis that vitamin A is involved in the regulation of iron release from the liver.

A solid-phase enzyme immunoassay method for the measurement of total and class-specific serum antibodies to Campylobacterjejuni was developed. The test was found to be both sensitive and specific. Immunoglobulin M, G, and A antibodies were detected in about 90% of sera collected from patients recovering from Campylobacter enteritis, with the pattern of appearance and decline of these antibodies conforming to that usually seen in an acute infection. A poor antibody response was noted in patients with intermittent or prolonged enteritis. The clinical implications and diagnostic value of this test are discussed.

No abstract