The deletion in both common types of hereditary persistence of fetal hemoglobin is approximately 105 kilobases

The most common forms of hereditary persistence of fetal hemoglobin (HPFH) involve large deletions that remove the adult delta and beta genes but leave the paired fetal genes (G gamma and A gamma) intact. The size of these deletions has previously eluded exact definition. Using pulsed-field gel electrophoresis and the enzyme SfiI, which cuts only rarely in genomic DNA, we have constructed a large-scale restriction map of the beta-globin cluster in normal and HPFH DNA. The deletions in HPFH-1, which occurs in American blacks, and in HPFH-2, which occurs in Ghanaian blacks, are found to be approximately 105 kilobases (kb) in length, though the endpoints are staggered by approximately 5 kb. The fact that two previously reported gamma delta beta-thalassemia deletions to the 5' side of the beta-globin cluster are also about 100 kb suggests a common mechanism, possibly involving the loss of a complete chromatin loop.     

The role of the gut in migraine: the oral 51-Cr EDTA test in recurrent abdominal pain

Sixteen children with recurrent abdominal pain (or: "recurrent syndrome"), regarded as migraine equivalent in childhood, were submitted to the 51-Cr EDTA gut permeability test. The results were compared with those obtained in 10 healthy young adults and in 11 control children. The gut permeability in the recurrent syndrome was significantly higher than in healthy adults and control children (p less than 0.0006): The following results were obtained: 4.83 +/- 0.40 (mean +/- SEM) in the children with recurrent abdominal pain, and 2.35 +/- 0.24 2.51 +/- 0.21 in the healthy young adults and control children, respectively. The implications of these findings as far as migraine is concerned, are discussed.     

Videofluorography and pulsed fluoroscopy using a 512 X 512-pixel digital image system

The combination of videofluorography and pulsed fluoroscopy using an analog videodisc system has previously been investigated with regard to image quality and potential for dose reduction. The authors found that the system could be improved still further by replacing the analog disc with a 512 X 512-pixel digital image system, thereby increasing fluoroscopic image quality and permitting stored images to be recorded with a multiformat camera. The pulsed method is compared with low-dose-rate fluoroscopy, in which a continuous image is obtained at 1/4 of the normal rate. Whereas image quality using a low dose rate was inadequate for any useful purpose, pulsed fluoroscopy was sufficient for all but the most critical stages of the examination.