Enzyme des Stärkeumsatzes in Bündelscheiden- und Palisadenchloroplasten von Zea mays

Summary Isolated chloroplasts from the bundle sheath cells show considerable activity of the ADPG- and UDPG-pyrophosphorylase (EC 2.7.7.9), ADPG- and UDPG-transglucosylase (EC 2.4.1.21), and the starch phosphorylase (EC 2.4.1.1). In chloroplasts of the palisade cells, on the other hand, only the UDPG-pyrophosphorylase is remarkably active.     

Geotropism and the lateral transport of auxin in the corn mutant amylomaize

Summary In coleoptiles of the amylomaize corn mutant (AM), the amyloplasts are much reduced in size in comparison with the wild type corn (WT), permitting a comparison of geotropic responsiveness as related to lateral displacement of amyloplasts and lateral transport of auxin. The amyloplasts of AM showed 30–40% lesser lateral redistribution in response to horizontal exposure in comparison with WT. With geotropic stimulation, the lateral transport of auxin in the direction of growth was 40–80% less, and the geotropic curvature by the coleoptiles was also significantly less in the mutant as compared with WT. These correlations support the hypothesis that the starch plastids serve as gravity sensors in the geotropic responses of coleoptiles.     

Tubular structures associated with the endothelial endoplasmic reticulum in glomerular capillaries of Rhesus monkey and nephritic man

Summary Round bodies, tubular profiles and crystalline images have been studied by electron microscopy in the endothelium of seven normal young Rhesus monkeys and in the renal glomerular endothelium of two nephritic human patients. The crystalline images are most frequently formed by aggregation of round bodies, 200–240 Å in diameter. In Rhesus monkeys a variety of crystalline images are seen. On the contrary, in nephritic patients round bodies and tubular profiles are rare and less organized. In the glomerular endothelium of two normal men they were not found.The results obtained suggest that the round bodies, the tubular profiles and the crystalline images result from sectioning of a system of undulating tubules associated with the smooth endoplasmic reticulum. In nephritic patients the formation of such a tubular system could represent a change taking place within the affected cells as a pathologic response to the disease.This work was supported by U.S. Public Health Service (N.H.I.), Grant AI-04527-03-04, and by the Consiglio Nazionale delle Ricerche (C.N.R.), Contributo 115/0815/0-1365. The Authors are greatly indebted to Miss Hermina Spiele for skilful technical assistance.     

Clinical Evaluation of Adriamycin,a New Antitumour Antibiotic

Adriamycin, a new antitumour antibiotic of the anthracycline group with a structural formula very similar to daunorubicin, has proved to have potent tumour-growth-inhibiting properties, and to be particularly effective in childhood malignancies. Though adriamycin produces a higher percentage of side-effects than daunorubicin—namely, stomatitis and alopecia—a lower dosage may be used for therapy.