Specificities of red cell membrane sites transporting three long chain fatty acids

We studied the specificities of human red cell membrane bindings of three long chain fatty acids, palmitic- arachidonic- and oleic acid, using resealed membranes, ghosts. Previously estimated binding capacities, affinities and inside/outside distributions suggest separated binding sites. This possibility is explored by estimating the binding properties of one fatty acid in the presence of one or two of the others. Binding capacities, nmol g-1 ghosts, of palmitic and arachidonic acid estimated simultaneously vs. separately are 27.4 +/- 2.7 vs. 29.0 +/- 2.1 (P < 0.6) and 6.5 +/- 0.6 vs. 5.5 +/- 0.5 (P < 0.2) respectively. The corresponding estimates for oleic- and palmitic acid are 36.5 +/- 2.0 vs. 34.0 +/- 2.2 (P < 0.4) and 28.4 +/- 1.8 versus 29.1 +/- 2.1 (P < 0.8). The binding sites are therefore independent. For each of the three fatty acids in the absence or in the presence of one or two of the others, the inside/outside distributions of the binding sites and the membrane transfer rate constants are elucidated by exchange efflux kinetics at 0 degrees C from ghosts with and without enclosed albumin. Packed ghosts loaded with radioactive acids are injected rapidly into a large volume of vigorously stirred buffer with albumin. With a resolution time of about 1-sec serial filtered ghost-free aliquots are collected and counted. The analyses show that palmitic- and oleic acid sites of transport are entirely independent but do not exclude that palmitic- and/or oleic acid binding may diminish the arachidonic acid affinity a little. The diversity combined with specificity suggests that the transport sites for long chain fatty acids are protein-determined microdomains of phospholipids.     

Photooxidation of P-960 and photoreduction of P-800 (bacteriopheophytin b-800) in reaction centers from Rhodopseudomonas viridis

CT scans of 9 patients with orbital pseudotumor (bilateral in 6 and unilateral in 3) showed findings distinct from those observed in Graves' ophthalmopathy. In bilateral involvement, they ranged from localized mass lesions to complete obiliteration of normal orbital CT anatomical landmarks; diffuse or multifocal lesions involving the posterior globe and muscle insertions were most typical of the diagnosis. However, findings in unilateral psedotumor may be indistinguishable from orbital mass lesions other than Graves' ophthalmopathy. Serial CT scans were used to show progression of disease and response to treatment.     

The ultrastructural and functional expression of the hepatocyte genome under conditions of prolonged inhibition of protein biosynthesis by cycloheximide. V]

A review of 76 Southampton children with Henoch-Sch?nlein purpura has confirmed that there is no evidence of a streptococcal aetiology in the majority of cases of this disease. Among these patients the frequency of preceding respiratory infection of all kinds was only 7 percent greater than that in controls. Data on month of admission in four areas of England and Scotland show that the incidence of the disease is lowest in the June-August period. Contrary to previous findings there is no marked peak of incidence in any single month.