Liver ferritin synthesis following chronic alcohol administration to rats: Modulation by propylthiouracil

Summary Liver ferritin synthesis was inhibited by 22.3% in rats treated with alcohol (2 g/kg) for 45 days. This inhibition was prevented by simultaneous administration (5 mg/kg) of propylthiouracil during the last 15 days. There was no significant effect on liver ferritin concentration.     

Specific and non-specific immunoglobulin synthesis in germfree mice immunized with ferritin by different routes

Résumé Après injection de ferritine de cheval, des souris C₂H axéniques développèrent des anticorps circulants ainsi que des immunoglobulines sans affinité pour l'antigène dans chacune des classes: IgA, IgM, IgG₁, et IgG₂. Après immunisation orale, la réponse spécifique fut exclusivement du type IgA, et la réponse non-spécifique principalement du type IgG₂ et IgA.

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Belgian American Educational Foundation Fellow.

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Staff Member of the Biology Division of Euratom, Euratom Publication No. 486.

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The Rega Institute for Medical Research, Louvain.     

Sucrose and starch synthesis in sugar cane plant

Zusammenfassung Im Gipfelknoten des ausgereiften Zuckerrohrs liess sich die Anwesenheit eines stärkebildenden Enzyms nachweisen, während die anderen stärkefreien Teile dieser Pflanze ein sukrosebildendes Enzymsystem enthalten. Diese Befunde stehen im Einklang mit der Speicherung von Stärke im Gipfelknoten und dem Fehlen von Stärke in den übrigen sukrosehaltigen Pflanzenteilen des Zukkerrohrs.     

Regulation of grasshopper fecundity,longevity and egg viability by plant growth hormones

Summary Abscisic acid, a plant growth hormone, added in water to the grass diet of a grasshopper, greatly reduces the reproductive rate, as does gibberellin A₃ at doses 10 times greater. Reciprocal seasonal variations in quantities of these hormones could synchronize the growth and reproduction of insects with their host plants in the field.Acknowledgments. I thank Drs J. Pickett, G. Strobel, D. Meyers, I. Mills, L. Jackson and J. Bradbury for helpful consultations; Dr R. Lund and Ms W. Whitmore for statistical analyses, and S. Baril, M. Gaudet, D. Wrobetz, J. Cotter and W. Wallace for technical assistance. This research was supported by the Montana Agricultural Experiment Station, Project 420, and is published as Journal Paper No. 865.     

Regulation of plant NR activity by reversible phosphorylation, 14-3-3 proteins and proteolysis

This review highlights progress in dissecting how plant nitrate reductase (NR) activity is regulated by Ca2+, protein kinases, protein kinase kinases, protein phosphatases, 14-3-3 proteins and protease(s). The signalling components that regulate NR have also been discovered to target other enzymes of metabolism, vesicle trafficking and cellular signalling. Extracellular sugars exert a major impact on the 14-3-3-binding status and stability of many target proteins, including NR in plants, whereas other stimuli affect the regulation of some targets and not others. We thus begin to see how selective or global switches in cellular behaviour are triggered by regulatory networks in response to different environmental stimuli. Surprisingly, the question of how changes in NR activity actually affect the rate of nitrate assimilation is turning out to be a tough problem.     

The effect of plant growth substances and natural products on RNA and DNA synthesis in leukocytes

Summary The effect of auxins, cytokinins, gibbrellins and phenolics on the incorporation of uridine and thymidine into the nucleic acids of human leukocytes was examined. Both the stimulation and inhibition of the incorporation of the precursors was noted. The auxins consistently promoted the incorporation of uridine.     

Effect of ferritin on liver catalase activity

Zusammenfassung Die Katalaseaktivität der Leber wurde nach Einspritzen von Ferritin in normale C₃H/St Mäuse beobachtet. Im Verlauf von sieben Tagen wurden die niedrigsten Katalaseaktivitäten am zweiten und vierten Tag nach Einspritzen des Ferritins festgestellt.     

Testimony and knowing how

Much of what we learn from talking and listening does not qualify as testimonial knowledge: we can learn a great deal from other people without simply accepting what they say as being true. In this article, I examine the ways in which we acquire skills or knowledge how from our interactions with other people, and I discuss whether there is a useful notion of testimonial knowledge how.     

Regulation of ppApp synthesis during sporulation of a conditionally asporogenous rifampin mutant ofBacillus subtilis

Summary The intracellular synthesis of ppApp in a conditionally asporogenous rifampin-resistant mutant ofBacillus subtilis stimulated to sporulate in the Sterlini-Mandelstam (SM) medium supplemented with ppApp is negligible and comparable to that of the non-sporulating culture. The formic acid extract from the sporulating culture stimulates sporulation of the mutant in SM medium.This paper was presented at the Annual Meeting of the American Society for Microbiology in Dallas, Texas, in March 1981. This work was supported in part by a grant from Research Corporation, New York, N.Y., USA.     

The effect of plant growth substances and natural products on RNA and DNA synthesis in leukocytes.

The effect of auxins, cytokinins, gibberellins and phenolics on the incorporation of uridine and thymidine into the nucleic acids of human leukocytes was examined. Both the stimulation and inhibition of the incorporation of the precursors was noted. The auxins consistently promoted the incorporation of uridine.     

Uptake of ferritin from the medium byTokophrya infusionum

Summary Tokophrya infusionum, a suctorian, is deprived of a mouth opening. The uptake of ferritin from the medium is accomplished through pits, invaginations of the plasma membrane which are permanent structures. From the pits containing ferritin, flat vesicles are pinched off transporting the ferritin to the cytoplasm.Supported by grant AI-08989 US Public Health Service.The author acknowledges gratefully the excellent technical assistance of Mrs Sondra Lewengrub.     

The passage of ferritin into jejunal epithelial cells

Résumé On a étudié la pénétration de la ferritine dans les cellules épithéliales du jejunum de rats adultes. Quelques molécules ont passé dans les cellules grâce aux petites vésicules. Ce processus est, peut-être, à la base de l'allergie intestinale.