ABSTRACT
OBJECTIVE: To study the clinical pattern of coeliac disease in children living in the northwest coast of Libya, to investigate the sensitivity and specificity of D-Xylose, fat load test and antigliadin antibody and their correlation to each other and changes in jejunal biopsy. METHODS: A 4 year prospective study began in 1993. It includes all suspected coeliacs referred to our department for further evaluation. All have suction jejunal biopsy using Crosby capsule performed for diagnosis, screened at the same time with one hour D-Xylose, 3-5 hours urinary D-Xylose, fat load test and antigliadin antibody and followed up for 2-4 years. RESULTS: The mean age at presentation was 8 years. There was no significant correlation between D-Xylose, fat load test and antigliadin antibody. Antigliadin antibody has 87.5% sensitivity and 50% specificity in this study. Three hours urinary D-Xylose has 93% sensitivity where as one hour D-Xylose has 82% sensitivity and only 25% specificity, whereas fat load test has 69% sensitivity. CONCLUSIONS: Blood and urinary D-Xylose and fat load tests are not useful for diagnosing coeliac disease. They have no correlation to each other or to jejunal histology. Antigliadin antibody is superior to the above tests.
Subject(s)
Celiac Disease/diagnosis , Adolescent , Antibodies/blood , Celiac Disease/blood , Child , Child, Preschool , Cohort Studies , Fat Emulsions, Intravenous , Gliadin/immunology , Humans , Infant , Jejunum/pathology , Libya , Sensitivity and Specificity , Triglycerides/blood , Xylose/metabolismABSTRACT
The Fraunhofer diffraction pattern of a narrow annular slit is recorded holographically to generate a beam that approximates a diffraction-free Bessel beam. The experimental limitations resulting from the annular-slit parameters such as the opening width and the transmission coefficient are discussed. The reconstructed Bessel beam is amplified by two-wave mixing in a photorefractive crystal. Thus the efficient conversion of a relatively large beam with a constant (or Gaussian) intensity distribution into a nondiffracting beam is achieved entirely by direct physical interference. We show that diffraction-free beams reproduced and amplified in this way can be applied to the measurement of the velocity of small objects by the use of the laser Doppler technique. In addition, the advantages of Bessel beams, especially in measuring the velocity of solids, are discussed.
