Characterization of corticosteroid receptors in natural killer cells: comparison with circulating lymphoid and myeloid cells

Lymphocytes mediating natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities are relatively refractory to the changes in circulatory traffic and intrinsic function induced in other cell types by in vivo and in vitro corticosteroids (CS). To investigate if such drug resistance could be attributed to differences in the CS receptor number of affinity (Kd) of these cells, these characteristics were determined in purified populations of large granular lymphocytes (LGL), monocytes, neutrophils (PMN), and T cells. All cell types displayed a single class of CS receptor of uniform affinity; however, LGL resembled monocytes and PMN in receptor number and Kd while T cells had significantly fewer sites per cell with lower Kd. These studies suggest that the unresponsiveness of NK activity to CS is not secondary to differences in CS receptor capacity or affinity.     

Physical characterization of lumazine proteins from Photobacterium

The physicochemical properties of Photobacterium lumazine proteins have been investigated. The molecular weights obtained by several physical techniques are in good agreement, and the averages are 2% and 8% higher than the minimum molecular weights from amino acid and ligand content. The average molecular weights, sedimentation coefficients, and molecular radii are respectively the following: Photobacterium leiognathi lumazine protein, 21 200 +/- 300, 2.18 S, and 22.9 A; Photobacterium phosphoreum lumazine protein, 21 300 +/- 500, 2.16 S, and 23.0 A. The hydrations of the lumazine proteins, estimated in several ways, indicate less hydration for P. leiognathi than for P. phosphoreum. The frictional ratios corrected for hydration give axial ratios less than 1.3 for both lumazine proteins. These values agree with those obtained by a combination of rotational and translational frictional parameters and elimination of the common hydrated volume terms. There is insufficient area on the exterior surface to accommodate hydration when the lumzine proteins are considered as smooth-surfaced ellipsoids. The required surface area can be accommodated however by surface roughness with a minimum of 30% internal water.     

Non-cross-reactive monoclonal antibodies to human chorionic gonadotropin generated after immunization with a synthetic peptide

Noncross-reactive monoclonal antibodies specific for human chorionic gonadotropin (hCG) were obtained after pre-selection for submolecular specificity with a synthetic peptide immunogen. Mice were immunized with a synthetic peptide representing a segment unique to the beta-subunit of hCG (amino acid residues 109-145), conjugated to diphtheria toxoid. We then derived nine different hybridomas that secreted monoclonal antibodies reactive with both native hCG and isolated C-terminal peptide, after somatic cell hybridization of immune spleen cells with a nonsecretory myeloma cell line. None of the nine monoclonal antibodies, termed beta-hCG-CTPa1----a9, reacted with hLH, hFSH, or hTSH, although these pituitary hormones display extensive amino acid sequence homology with hCG. The noncross-reactive anti-beta-hCG monoclonal antibodies show apparent association constants on the order of 10(9) to 10(10) M-1. A sandwich-type enzyme-linked immunosorbent assay was set up with cut-off values of around 5 mIU/ml. These antibodies might have important implications for: a) improving the diagnosis and clinical management of pregnancy; b) monitoring the course of development of carcinomas which secrete the hormone, through in vitro assays or in vivo radioimmunodetection; c) evaluating the antibodies' therapeutic potential against such carcinomas; d) studying the biologic functions of the C-terminal segment of beta-hCG; and e) addressing the anti-fertility effect of antibodies raised against that segment.     

Etodolac: effect on prostaglandin concentrations in gastric mucosa of rats

Etodolac is a structurally novel compound exhibiting potent analgesic and anti-inflammatory activity in laboratory animals and man, with excellent G. I. tolerance. Like other nonsteroidal anti-inflammatory drugs (NSAIDs) etodolac inhibits prostaglandin (PG) biosynthesis. In view of the cytoprotective role of PGE2, we have investigated in normal rats the effect of etodolac on the gastric mucosal concentration of PGE2 as well as of 6-keto-PGF1 alpha, the stable metabolite of prostacyclin; naproxen and piroxicam served as reference NSAIDs. The orally effective anti-inflammatory doses in the chronic arthritic rat model (3 mg/kg for etodolac and naproxen; 0.5 mg/kg for piroxicam), and their arbitrarily selected multiples of 10 were used. Rats were killed at 1, 2, 6 and 24 hr after single doses and the PG concentrations were measured by RIA. With the low dose, 2 and 6 hr after dosing, etodolac diminished the PGE2 concentration by 20-25% (vs control) while naproxen and piroxicam caused a fall of 53-65%; the difference between etodolac and the untreated control group is not statistically significant but the difference between etodolac and both piroxicam and naproxen is significant (p less than 0.001). At the high doses, the lowering in PGE2 was similar after all three drugs, i.e. about 70% at 1 and 2 hr; 50% at 6 hr, and 20-50% at 24 hr after dosing. Except for the consistently smaller reduction of concentrations after etodolac, the effects on 6-keto-PGF1 alpha concentration followed a similar pattern but the differences are not significant. The lack of the G.I. irritation of etodolac in rats and man at therapeutically effective doses may be attributed to the benefits of the relatively short-lived and slight decrease in gastric mucosal PGE2 concentrations found in this study.     

Phosphorylation of ribosomal and ribosome-associated proteins in isoproterenol-induced cardiac hypertrophy

Cardiac hypertrophy in adult rabbits was induced by subcutaneous injection of isoproterenol. The rate of [3H]leucine incorporation into acid insoluble material was increased and the extent of [32P]phosphate incorporation into several ribosomal proteins was altered. Specifically, a ribosomal protein with a molecular weight of 32,000 from the 40S ribosomal subunit showed a five-fold increase in phosphate incorporation in the hypertrophic heart whereas a protein with a molecular weight of 28,000 from the 60S subunit showed a four-fold decrease. Phosphorylation of ribosome-associated proteins, which could be removed from ribosomes with 0.72 M KCl, was also changed in the hypertrophic hearts. Six major phosphoproteins (with molecular weights 62,000, 49,000, 36,000, 30,000, 20,000 and 12,000) were detected in both the normal and the hypertrophic hearts. Phosphorylation of the 62 K and the 49 K protein was increased by two- and three-fold, respectively, in the hypertrophic hearts, whereas phosphorylation of the 36 K and the 30 K protein decreased by two-fold. The level of phosphorylation of the 20 K and the 12 K protein was not significantly changed in hypertrophic hearts.     

Characterization of algae using regularities

The weight fraction carbon and reductance degree of algae are reviewed for literature data. Average values are compared with values for yeast and bacteria. The results show that the standard deviation and coefficient of variation are small as long as the algae are grown under adequate nutritional conditions. For nitrogen-deficient growth conditions, the storage of lipids has been observed; this results in values of weight fraction carbon and reductance degree which are larger than the average values.     

Interaction of fatty acids with lipid bilayers

We present a method by which it is possible to describe the binding of fatty acids to phospholipid bilayers. Binding constants for oleic acid and a number of fatty acids used as spectroscopic probes are deduced from electrophoresis measurements. There is a large shift in $\text{p}\text{K}$ value for the fatty acids on binding to the phospholipid bilayers, consistent with stronger binding of the uncharged form of the fatty acid. For dansylundecanoic acid, fluorescence titrations are consistent with the binding constants derived from the electrophoresis experiments. For 12-(9-anthroyloxy)stearic acid, fluorescence and electrophoresis data are inconsistent, and we attribute this to quenching of fluorescence at high molar ratios of 12-anthroylstearic acid to phospholipid in the bilayer.