Quantitative assessment of changes in aortic dimensions in response to in situ perfusion fixation at physiological pressures

The study of atherosclerosis often involves evaluation of aortic tissue. The effects of the fixation process on aortic dimensions is and issue of concern. Using aortography we have quantitatively assessed changes in aortic dimensions during in situ perfusion fixation at physiological pressures with 2 commonly used fixative solutions. Two dimensional aortic luminal (TDAL) areas, obtained by planimetry from X-ray images after opaque dye injection (aortography), decreased both early during perfusion fixation and later with cessation of the physiological pressure. These reductions were variable, irrespective of the fixation solution used. Long-term perfusion fixation (10 1/2-12 h) reduced, but did not prevent, changes in TDAL area compared with changes observed following a 1-h perfusion fixation period.

Cell-mediated immunity in patients with cystic fibrosis

Leucocytes from 26 patients with cystic fibrosis (CF) and 18 healthy controls were investigated by migration inhibition induced by a variety of antigens. In patients with CF cell-mediated immunity was found to human lung and pancreatic tissue extracts as well as to Aspergillus fumigatus, Pseudomonas aeruginosa, and food antigens but not to brain, heart, or kidney. Those patients with the severest form of the disease had the greatest impairment of cell-mediated immunity, but this impairment could be reversed by steroid treatment. Cell-mediated cytotoxicity may also be concerned in the pathogenesis of CF.