Alterations in the phospholipid composition ofNocardia polychromogenes during growth

Summary The major phospholipid classes ofNocardia polychromogenes were quantitated at different stages of the growth cycle. Significant differences were observed both in the total lipid phosphorus per g (dry weight) of cells, and in the relative percentages of individual phospholipids. The total amount of lipid-phosphorus increased throughout the growth cycle. Cardiolipin and phosphoinositides contents increased with significant decrease in phosphatidyl ethanolamine and unknown phospholipids.Acknowledgments. This investigation was supported in part by a grant from the Indian Council of Medical Research. Technical assistance of Mr Adarsh Kumar is acknowledged.     

Subcellular distribution of mannophosphoinositides in Mycobacterium smegmatis during growth

Subcellular distribution of total phospholipids and mannophosphoinositides (mannosides) was examined in Mycobacterium smegmatis ATCC 607 during its transition from the early exponential to the stationary phase of growth. There was relatively more of these substances in the cell membrane than in the cell wall, and the total amount increased with the age of the culture. Among individual mannosides, dimannophosphoinositides (dimannosides) were distributed equally in the cell wall and membrane. However, hexamannophosphoinositides (hexamannosides) were more predominant in the cell membrane, and the level increased with the age of the culture.     

Effect of clofibrate on the phospholipid biosynthesis in rat liver.

The effect of clofibrate on rat liver phospholipid biosynthesis was studied using 32P as a precursor. Phospholipid classes, levels and specific radioactivity were evaluated. Significant increases in levels of phosphatidylethanolamine and phosphatidylcholine were found and could account for the observed increase in total phospholipids. Specific activity of phosphatidylserine increased and that of phosphatidylethanolamine decreased. This fact suggests that clofibrate seems to alter the systems engaged in the transformation occurring within the different classes of phospholipids but not the de novo biosynthesis.     

Lipids in the egg shell of the ostrich (Struthio camelus) (author's transl)]

The egg shell (with cuticle) of the ostrich contained a total lipid concentration of 0.19 mg/g egg shell; the phospholipids constituted the major portion, among the neutral' lipids cholesterol esters, cholesterol and free fatty acids were identified. The egg shell lipids showed a stimulating effect on the crystal growth of calcium carbonate; the highest rate of crystal growth was observed with the phospholipid fraction.     

Effect of clofibrate on the phospholipid biosynthesis in rat liver

Summary The effect of clofibrate on rat liver phospholipid biosynthesis was studied using³²P as a precursor. Phospholipid classes, levels and specific radioactivity were evaluated. Significant increases in levels of phosphatidylethanolamine and phosphatidylcholine were found and could account for the observed increase in total phospholipids. Specific activity of phosphatidylserine increased and that of phosphatidylethanolamine decreased. This fact suggests that clofibrate seems to alter the systems engaged in the transformation occurring within the different classes of phospholipids but not the de novo biosynthesis.     

Effect of growth factor deficiency on nystatin sensitivity inSaccharomyces cerevisiae

Summary The nystatin sensitivity, as well as the levels of total sterols and individual phospholipids ofSaccharomyces cerevisiae are influenced by variations in the supply of growth factors.     

Role of inorganic phosphate in total biliary phosphorus determination

Total phosphorus, inorganic phosphate, and phospholipids were measured in bile of rats and guinea pigs during choleresis and cholestasis produced by taurocholate and taurolithocholate, respectively. Under either experimental condition, total biliary phosphorus concentrations increased significantly in both species, due primarily to an increase in inorganic phosphate. These studies indicate that, if total phosphorus is taken as an estimate of biliary phospholipid concentration, correction for inorganic phosphate is essential under conditions associated with changes in bile secretory function.     

Incorporation of 32P into renal phospholipids of mice during postnatal growth

During the first 40 days of life the rate of incorporation of 32P into total phospholipids and into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, diphosphatidylglycerol, phosphatidic acid and phosphatidylinositol of mouse kidney was by some 25-35% higher than in older animals. Results suggest a different involvement of cellular membranes during of normal and compensatory renal growth.     

Role of inorganic phosphate in total biliary phosphorus determination

Summary Total phosphorus, inorganic phosphate, and phospholipids were measured in bile of rats and guinea pigs during choleresis and cholestasis produced by taurocholate and taurolithocholate, respectively. Under either experimental condition, total biliary phosphorus concentrations increased significantly in both species, due primarily to an increase in inorganic phosphate. These studies indicate that, if total phosphorus is taken as an estimate of biliary phospholipid concentration, correction for inorganic phosphate is essential under conditions associated with changes in bile secretory function.This work was supported by grant HD-17556 from the National Institute of Child Health and Human Development.     

Incorporation of32P into renal phospholipids of mice during postnatal growth

Summary During the first 40 days of life the rate of incorporation of³²P into total phospholipids and into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, diphosphatidylglycerol, phosphatidic acid and phosphatidylinositol of mouse kidney was by some 25–35% higher than in older animals. Results suggest a different involvement of cellular membranes during of normal and compensatory renal growth.     

Lipid accumulation by a cellulolytic strain of Aspergillus niger.

Lipid accumulation by a cellulolytic mold, Aspergillus niger, was studied. The amount of lipid accumulated ranged from 13.6-16.6% on various carbon sources, namely glucose, xylose, avicel (microcrystalline cellulose) and bagasse (a natural lignocellulosic substrate). Neutral lipids, phospholipids and glycolipids of the mycelia varied from 41.0-46.2%, 34.9-38.4% and 18.7-22.6% of total lipids, respectively. Unsaturated fatty acids comprised around 80% of total fatty materials with linoleic and oleic acid predominating. Of the four nitrogen sources tested, NH4Cl was the best source for lipid synthesis from cellulose (bagasse). Optimum temperature range for growth and lipid synthesis was 25-30 degrees C.     

Effect of 5-thio-D-glucose on testicular lipids of mice

Summary Spermatogenesis is reported to be completely inhibited by 5-thio-D-glucose in mice. In an investigation of this inhibition, testicular lipid constituents, namely, total lipids, phospholipids, triacylglycerol, free and total cholesterol, 3-hydroxy-3-methylglutaryl-coenzyme A reductase and NADPH generators like glucose-6-phosphate dehydrogenase, intubation for 21 days. Significant increase in cholesteryl ester, glucose-6-phosphate dehydrogenase activity and malic enzyme and a decrease in free cholesterol and phospholipids were observed.Acknowledgments. We are thankful to the Director, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry 6, India for permission to do the work and Mr T. Natarajan, Department of Biochemistry of ministerial assistance.     

Effect of menstrual stress on serum lipid levels

Summary The effect of menstrual stress on serum lipid levels has been investigated in 28 healthy unmarried student nurses aged between 19 and 25 years, with histories of regular 26–30 day menstrual cycles. There were definite and similar patterns of changes in serum cholesterol, phospholipids and triglycerides during different phases of the menstrual cycle.The authors acknowledge with pleasure the useful discussion with Dr Radium D. Bhattacharya, the statistical analysis by Shiri N. P. Gopinath and Dr A. R. N. Setalvad.     

Adaptation of lipase and phospholipase A activities in pancreas and pancreatic juice in rats with diets rich in triglycerides and phospholipids]

Lipid rich diets containing about 20% of triglycerides or phospholipids given to Rats during 2 months were observed to increase lipase and phospholipase A2 activities in pancrease and pancreatic juice. The phospholipase and lipase activities are higher, respectively, on the phospholipid and triglyceride diet. Lower effects are observed after a 7-day administration of diet containing 40% of total lipid.     

Interaction between PGE2 and EGF receptor through MAPKs in mouse embryonic stem cell proliferation

Identifying the small molecules that permit precise regulation of embryonic stem (ES) cell proliferation should further support our understanding of the underlying molecular mechanisms of self renewal. In the present study, we showed that PGE₂ increased [³H]-thymidine incorporation in a time and dose dependent manner. In addition, PGE₂ increased the expression of cell cycle regulatory proteins, the percentage of cells in S phase and the total number of cells. PGE₂ obviously increased E-type prostaglandin (EP) receptor 1 mRNA expression level compare to 2, 3, 4 subtypes. EP1 antagonist also blocked PGE₂-induced cell cycle regulatory protein expression and thymidine incorporation. PGE₂ caused phosphorylation of protine kinase C, Src, epidermal growth factor (EGF) receptor, phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation, and p44/42 mitogen-activated protein kinase (MAPK), which were blocked by each inhibitors. In conclusion, PGE₂-stimulated proliferation is mediated by MAPK via EP1 receptor-dependent PKC and EGF receptor-dependent PI3K/Akt signaling pathways in mouse ES cells. Received 30 January 2009; received after revision 03 March 2009; accepted 10 March 2009     

Lipid accumulation by a cellulolytic strain ofAspergillus niger

Lipid accumulation by a cellulolytic mold,Aspergillus niger, was studied. The amount of lipid accumulated ranged from 13.6–16.6% on various carbon sources, namely glucose, xylose, avicel (microcrystalline cellulose) and bagasse (a natural lignocellulosic substrate). Neutral lipids, phospholipids and glycolipids of the mycelia varied from 41.0–46.2%, 34.9–38.4% and 18.7–22.6% of total lipids, respectively. Unsaturated fatty acids comprised around 80% of total fatty materials with linoleic and oleic acid predominating. Of the four nitrogen sources tested, NH₄Cl was the best source for lipid synthesis from cellulose (bagasse). Optimum temperature range for growth and lipid synthesis was 25–30°C.     

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.     

Lipide in der Eischale vom Strauss (Struthio camelus)

Summary The egg shell (with cuticle) of the ostrich contained a total lipid concentration of 0.19 mg/g egg shell; the phospholipids constituted the major portion, among the neutral lipids cholesterol esters, cholesterol and free fatty acids were identified. The egg shell lipids showed a stimulating effect on the crystal growth of calcium carbonate; the highest rate of crystal growth was observed with the phospholipid fraction.

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Forschergruppe Biomineralisation. Von der Deutschen Forschungsgemeinschaft gefördertes Projekt.

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Herrn K. Kasimir danken wir für seine experimentelle Unterstützung bei den Lipiduntersuchungen. Herrn Prof. H.-J. Meyer, Mineralogisches Institut Bonn, danken wir für die Messungen der Kristallwachstumsgeschwindigkeit.