Chromsome aberrations in cattle raised on bracken fern pasture

Summary Thirteen cows maintained on natural bracken fern (Pteridium aquilinum) were analyzed cytogenetically. The frequency of structural chromosome aberrations detected in peripheral blood cells was significantly higher when compared to that detected in animals raised on pasture containing no bracken fern. We discuss the clastogenic action of fern and its synergistic action with infection by type 2 and 4 papilloma virus in the same animals.Acknowledgments. We are grateful to Dr F. J. Benesi, Dr J. L. Guerra and Dr I. L. Sinhorini for performing some of the clinical and pathological analyses; O. P. Ferraz, L. A. Tadeu Dias, L. F. Feitosa and A. M. N. Paiva for technical assistance; and to Dr N. H. C. Castro and Dr C. de Araujo Peres for critical and statistics review, respectively. Research was supported by CNPq FAPESP and CAPES.     

Temporal effects of ACTH,indomethacin and 7-oxa-13-prostynoic acid upon glucocorticoid production by the human adrenal

Summary Indomethacin or 7-oxa-13-prostynoic acid does not alter basal adrenal cortisol output. Preincubation in either, depresses subsequent ACTH-stimulated cortisol output below ACTH alone and controls. Either inhibitor following ACTH preincubation blunts normal ACTH-stimulated cortisol production.     

Inhibition of molybdenum blue formation by ATP

Summary Molybdenum blue formation was not affected by the presence of ATP up to a concentration of 1.2 mM/l. At higher concentrations the color development was inhibited relative to ATP concentration, finally reaching complete inhibition. Auto-hydrolysis of ATP was found at a rate of 1.4%/h. An exact determination of inorganic phosphate in the presence of easily hydrolyzed phosphate esters requires the measurement of extinction at fixed time intervals and extrapolation back to time zero.Acknowledgment. This work was supported by a grant of the Deutsche Forschungsgemeinschaft.     

Dedekinds „Bunte Bemerkungen“ zu Kroneckers „Grundzüge“

Ohne Zusammenfassung Vorgelegt von M. Kline The work of H. Edwards was supported by part by the U. S. National Science Foundation Grant SOC-7905162 and by the Vaughn Foundation.     

Characterization of the self-palmitoylation activity of the transport protein particle component Bet3

Bet3, a transport protein particle component involved in vesicular trafficking, contains a hydrophobic tunnel occupied by a fatty acid linked to cysteine 68. We reported that Bet3 has a unique self-palmitoylating activity. Here we show that mutation of arginine 67 reduced self-palmitoylation of Bet3, but the effect was compensated by increasing the pH. Thus, arginine helps to deprotonate cysteine such that it could function as a nucleophile in the acylation reaction which is supported by the structural analysis of non-acylated Bet3. Using fluorescence spectroscopy we show that long-chain acyl-CoAs bind with micromolar affinity to Bet3, whereas shorter-chain acyl-CoAs do not interact. Mutants with a deleted acylation site or a blocked tunnel bind to Pal-CoA, only the latter with slightly reduced affinity. Bet3 contains three binding sites for Pal-CoA, but their number was reduced to two in the mutant with an obstructed tunnel, indicating that Bet3 contains binding sites on its surface.