Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in humanAscaris lumbricoides

Summary The phospholipid level in the human parasitic nematodeAscaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.Acknowledgment. We thank ProfessorP. A. Kurup of this Department for keen interest and helpful advice.     

Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in human Ascaris lumbricoides.

The phospholipid level in the human parasitic nematode Ascaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.     

Extracellular Ca2+ and Mg2+ and cellular metabolism of phospholipids.

High extracellular concentration of Ca2+ inhibits the incorporation of 32P into the cellular phospholipids. This effect is more significant in neoplastic than in normal cells, and it is accompanied by an increase of the percentual incorporation into the lecithin fraction.     

Occurrence of Rhodoquinone-9 in the muscle of ascaris lumbricoides var. suis

Zusammenfassung Es gelang, aus der Epithelmuskelzelle vonAscaris lumbricoides var.suis Rhodochinon (Methoxylgruppe in Ubichinon mit einer Aminogruppe substituiert) zu extrahieren und kristallin zu gewinnen. Die Spektralmessungen (UV-, IR-, Massen-Spektren) ergeben, dass es sich beim Rhodochinon um Rhodochinon-9 handelt.     

On the phospholipids of adultAncylostoma caninum

Summary The phospholipid composition ofAncylostoma caninum has been examined. Phospholipids amounted to 0.9% of the wet weight of the parasite. Ethanolamine and choline containing lipids comprised about 76% of the total phospholipids. Lysolecithin, sphingomyelin, phosphatidyl inositol and phosphatidyl serine were present in minor amounts. Cerebrosides and sulfatides were also identified.Acknowledgements. We wish to acknowledge the contributions of Mr Ashok Chopra in the initial part of this work. Thanks are due to Mr Adarsh Kumar for skilled assistance.     

Metabolism of phospholipids in scorbutic guinea-pigs

Zusammenfassung Akuter Vitamin C-Mangel verursacht bei Meerschweinchen vorübergehenden Anstieg des Phospholipidspiegels im Blutserum, erhöhte Inkorporation des P³²-Phosphates in die Leberphospholipide und eine markante Akkumulation von Leberphospholipiden.     

Evidence for the extranuclear localization of thymosins in thymus

A new radioimmunoassay has been developed for thymosin ₄ by generating rabbit polyclonal antibodies against the synthetic N-terminal peptide fragment 1–15 coupled to KLH. The synthetic analogue [Tyr¹²]-thymosin ₄ (1–15) was used as tracer. This radioimmunoassay, with a useful range of 10–1000 pmoles, showed cross-reactivity with the second homologous -thymosin of man and rat (thymosin ₁₀) but not of calf (thymosin ₉). This radioimmunoassay, together with an improved radioimmunoassay for the N-terminus of parathymosin , was employed for the measurement of the levels of thymosin ₄ and parathymosin in nuclear and extranuclear extracts of calf thymus. The bulk of these polypeptides was found in the extranuclear material whereas only traces were observed in the nuclear environment, which indicates the extranuclear localisation of - and -thymosins.     

Evidence for the intracellular accumulation of anandamide in adiposomes

Anandamide is a lipid messenger that carries out a wide variety of biological functions. It has been suggested that anandamide accumulation involves binding to a saturable cellular component. To identify the structure(s) involved in this process, we analyzed the intracellular distribution of both biotinylated and radiolabeled anandamide, providing direct evidence that lipid droplets, also known as adiposomes, constitute a dynamic reservoir for the sequestration of anandamide. In addition, confocal microscopy and biochemical studies revealed that the anandamide-hydrolase is also spatially associated with lipid droplets, and that cells with a larger adiposome compartment have an enhanced catabolism of anandamide. Overall, these findings suggest that adiposomes may have a critical role in accumulating anandamide, possibly by connecting plasma membrane to internal organelles along the metabolic route of this endocannabinoid. S. Oddi, F. Fezza: These authors contributed equally to the study.     

Evidence for a hypocalcemic factor in the hypothalamus

Zusammenfassung Es konnte gezeigt werden, dass ein Hypothalamus-Extrakt von Meerschweinchen an hypophysektomierten Raten eine deutliche Senkung des Plasmakalziums bewirkte.     

Quantitative changes of the free phospholipids in the sea-urchin egg at fertilization

Riassunto Nelle uova diArbacia lixula si osserva una diminuzione di fosfolipidi liberi nei primi minuti dopo la fecondazione, seguita poi da un aumento che riporta, nel corso di 15 min circa, la quantità di fosfolipidi liberi al valore delle uova vergini. Non pare che vi sia alcuna variazione quantitativa nella frazione dei fosfolipidi legati.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in 32P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of 32P was by endocytosis and/or fusion.     

Evidence for the selection of forecasting methods

Reid (1972) was among the first to argue that the relative accuracy of forecasting methods changes according to the properties of the time series. Comparative analyses of forecasting performance such as the M‐Competition tend to support this argument. The issue addressed here is the usefulness of statistics summarizing the data available in a time series in predicting the relative accuracy of different forecasting methods. Nine forecasting methods are described and the literature suggesting summary statistics for choice of forecasting method is summarized. Based on this literature and further argument a set of these statistics is proposed for the analysis. These statistics are used as explanatory variables in predicting the relative performance of the nine methods using a set of simulated time series with known properties. These results are evaluated on observed data sets, the M‐Competition data and Fildes Telecommunications data. The general conclusion is that the summary statistics can be used to select a good forecasting method (or set of methods) but not necessarily the best. Copyright © 2000 John Wiley & Sons, Ltd.