The New England journal of medicine
-
In a two-year prospective study, we examined the effect of respiratory viral infections on pulmonary function in 49 patients with cystic fibrosis (mean age, 13.7 years). Nineteen normal siblings (mean age, 14) served as controls. Subjects were assessed quarterly and at the time of any respiratory illness. ⋯ Respiratory illnesses were reported significantly more often in the patients (3.7 per year) than in the normal siblings (1.7 per year), although the frequency of proved viral infections (1.67 per year) was identical. In the patients with cystic fibrosis significant correlations (P less than 0.0001) were found between the annual incidence of viral infections and every measure of disease progression in the two-year period, including the rate of decline of the Shwachman score (r = 0.71), the percentage of ideal weight for height (r = 0.80), the forced vital capacity (r = 0.85), the forced expiratory volume in the first second (r = 0.84), the forced midexpiratory flow rate (r = 0.68), and the frequency (r = 0.53) and duration (r = 0.84) of hospitalizations for respiratory exacerbations. We conclude that frequency of viral respiratory infections is closely associated with pulmonary deterioration in patients with cystic fibrosis.
-
A six-year-old girl with severe hypercholesterolemia and atherosclerosis had two defective genes at the low-density-lipoprotein (LDL) receptor locus, as determined by biochemical studies of cultured fibroblasts. One gene, inherited from the mother, produced no LDL receptors; the other gene, inherited from the father, produced a receptor precursor that was not transported to the cell surface and was unable to bind LDL. The patient degraded intravenously administered 125I-LDL at an extremely low rate, indicating that her high plasma LDL-cholesterol level was caused by defective receptor-mediated removal of LDL from plasma. ⋯ Thus, the transplanted liver, with its normal complement of LDL receptors, was able to remove LDL cholesterol from plasma at a nearly normal rate. We conclude that a genetically determined deficiency of LDL receptors can be largely reversed by liver transplantation. These data underscore the importance of hepatic LDL receptors in controlling the plasma level of LDL cholesterol in human beings.