Auxin dependence and auxin oxidase of cultured sycamore cells

Summary Quantitative and qualitative differences in auxin-oxidases extracted from auxin-dependent (S) or auxin-independent (MB) sycamore cells were analyzed. MB auxin-oxidases have a higher activity, but the molecular weight of this enzymatic complex is lowered by freeze-drying, without loss of the activity. Correlations with auxin-independence are discussed in this context.     

The effects of cocaine in the production of cardiovascular anomalies inβ-Adrenoreceptor stimulated chick embryos

Summary Cocaine potentiates the effects of epinephrine and norepinephrine in terms of aortic arch malformation in embryonic chicks. Cocaine itself induces aortic arch malformations when administered in large doses.This study was supported by grant No. HL 18050, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland.     

Concentration of ‘available’ unesterified cholesterol in human plasma as evaluated from inhibition of hemolysis by lucensomycin

Summary The unesterified cholesterol content of plasma samples can be evaluated from the extent of inhibition of lucensomycin-induced hemolysis. The test measures, however, only the fraction of cholesterol which is available for interaction with lucensomycin, this availability being adversely affected by high phospholipid-cholesterol ratios.     

Inhibition by syngenic erythrocytes of in vitro growth of colonics from murine bone marrow cells

Summary The growth of colonies from murine bone marrow cells in soft agar cultures was found to be inhibited by 0.1 ml or more 50% washed syngenic erythrocyte suspension per 1.2 ml culture volume.     

The structure of locomotor activity in bilobectomized cockroaches (Blaberus fuscus)

Summary The aperiodic activity patterns of bilobectomized cockroaches can largely be described by simple stochastic regularities: a) there are no correlations between the lengths of successive activity bursts and rest pauses, b) the probabilities for the transition from activity to rest and from rest to activity are time-independent. The activity sequence is strongly influenced by singular temperature steps or temperature cycles.     

Desacetylscalaradial,a cytotoxic metabolite from the spongeCacospongia scalaris

Summary From the marine spongeCacospongia scalaris, scalaradial1, desacetylscalaradial2, and heteronemin3 were isolated. Compound2 showed potent cell growth inhibition. The stereochemistry of3 is briefly discussed.Acknowledgments. The authors are grateful to Prof. T. Hase and Mr R. Nakai for collecting the sponge and to Dr s. Tanida for the sponge identification.     

Intracellular topography of immunoreactive gastrin demonstrated using electron immunocytochemistry

Summary Gastrin (G)-producing cells from the mammalian gastric antrum have been investigated using computer-assisted morphometry and a novel double colloidal gold-labeled-immunoglobulin electron immunocytochemical procedure. Correlation analysis of human antral G-cells indicates (p<0.001) that a single population of granules exists with small (160 nm) electron-dense and large (240 nm) electron-lucent forms representing the extremes. Non-crossreacting region-specific antisera have been used to visualize G-17 and G-34 (progastrin) to the small electron-dense granules and G-17 to the other intermediate forms. From the results we propose a topographic segregation of immunoreactive gastrins within 2 apparently distinct granule subclasses and suggest that this may represent the pathway of granule maturation.