Reproduction of Entomopathogenic Nematodes for Use in Pest Control.

The growing interest in the use of entomopathogenic nematodes and their symbiotic bacteria as promising biocontrol agents of many arthropod pests and pathogens has created running technologies to expand their use globally. The related laboratory procedures and tests on these nematodes such as their isolation, count, culture, identification, pathogenicity, virulence, and environmental tolerance should form the solid basis for such an expansion with reliable uses. Extensive practical details of such procedures and tests as well as how to identify and overcome the problems associated with these aspects are addressed in this chapter.

Exploiting Plant-Phytonematode Interactions to Upgrade Safe and Effective Nematode Control.

Plant-parasitic nematodes (PPNs) bring about substantial losses of economic crops globally. With the environmental and health issues facing the use of chemical nematicides, research efforts should focus on providing economically effective and safe control methods. The sound exploitation of plant-PPN interactions is fundamental to such efforts. Initially, proper sampling and extraction techniques should be followed to avoid misleading nematode data. Recent evolutions in plant-PPN interactions can make use of diverse non-molecular and molecular approaches to boost plant defenses. Therefore, PPN control and increasing crop yields through single, sequential, dual-purpose, and simultaneous applications of agricultural inputs, including biocontrol agents, should be seriously attempted, especially within IPM schemes. The use of biologicals would ideally be facilitated by production practices to solve related issues. The full investment of such interactions should employ new views of interdisciplinary specialties in the relevant modern disciplines to optimize the PPN management. Having an accurate grasp of the related molecular events will help in developing tools for PPN control. Nonetheless, the currently investigated molecular plant-PPN interactions favoring plant responses, e.g., resistance genes, RNA interference, marker-assisted selection, proteinase inhibitors, chemo-disruptive peptides, and plant-incorporated protectants, are key factors to expanding reliable management. They may be applied on broader scales for a substantial improvement in crop yields.

Can Agricultural Practices in Strawberry Fields Induce Plant-Nematode Interaction towards Meloidogyne-Suppressive Soils?

The importance of benign approaches to manage the root-knot nematodes (RKNs, Meloidogyne spp.) in strawberry farms has become more evident with increasing strawberry production and export in Egypt. Therefore, data accumulated on biosolarization and soil amendments to favor beneficial microorganisms and maximize their impact on RKN management are built on a robust historical research foundation and should be exploited. We examined RKN population levels/parameters in three strawberry export governorates, six farms per governorate, to characterize the exact production practices that are responsible for RKN-suppressive soils. All selected farms enjoyed soil biodisinfestation resulting from incorporating organic amendments followed by a plastic cover to suppress soil pathogens. Various safe and inexpensive agricultural practices in the El-Ismailia and El-Beheira governorates were compared to the toxic and expensive fumigants that could eliminate RKNs in the Al-Qalyubia governorate. Two farms at El-Ismailia were of special interest as they ultimately showed almost zero counts of RKNs. The two farms were characterized by incorporating cow manure [containing 0.65% total nitrogen, 21.2 carbon to nitrogen (C/N) ratio] and poultry manure (0.72% total nitrogen, 20.1 C/N ratio) followed by soil solarization via transparent, 80-µm thick plastic covers for 60−65 summer days as pre-strawberry cultivation practices, and similar covers were used after transplanting. Typically, the longer the pre-plant soil solarization period with thicker transparent plastic covers, the better it could suppress the RKN population densities in the tested farms. Their soils were characterized by relatively high pH and low electrical conductivity. The significant development in biocontrol genera/species abundance and frequency could explain the lower (p < 0.0001) RKN population levels inhabiting the farms of El-Ismailia than the El-Beheira governorate. These factors could provide the first approximation of key practices and factors that could collectively contribute to distinguishing and exploiting soil suppressiveness against RKNs. We discussed edaphic properties and production practices that could modulate populations of natural RKN antagonists for sustainable strawberry cultivation.

Xenorhabdus spp.: An Overview of the Useful Facets of Mutualistic Bacteria of Entomopathogenic Nematodes.

Mounting concern over the misuse of chemical pesticides has sparked broad interest for safe and effective alternatives to control plant pests and pathogens. Xenorhabdus bacteria, as pesticidal symbionts of the entomopathogenic nematodes Steinernema species, can contribute to this solution with a treasure trove of insecticidal compounds and an ability to suppress a variety of plant pathogens. As many challenges face sound exploitation of plant-phytonematode interactions, a full useful spectrum of such interactions should address nematicidal activity of Xenorhabdus. Steinernema-Xenorhabdus complex or Xenorhabdus individually should be involved in mechanisms underlying the favorable side of plant-nematode interactions in emerging cropping systems. Using Xenorhabdus bacteria should earnestly be harnessed to control not only phytonematodes, but also other plant pests and pathogens within integrated pest management plans. This review highlights the significance of fitting Xenorhabdus-obtained insecticidal, nematicidal, fungicidal, acaricidal, pharmaceutical, antimicrobial, and toxic compounds into existing, or arising, holistic strategies, for controlling many pests/pathogens. The widespread utilization of Xenorhabdus bacteria, however, has been slow-going, due to costs and some issues with their commercial processing. Yet, advances have been ongoing via further mastering of genome sequencing, discovering more of the beneficial Xenorhabdus species/strains, and their successful experimentations for pest control. Their documented pathogenicity to a broad range of arthropods and pathogens and versatility bode well for useful industrial products. The numerous beneficial traits of Xenorhabdus bacteria can facilitate their integration with other tactics for better pest/disease management programs.

Understanding Molecular Plant-Nematode Interactions to Develop Alternative Approaches for Nematode Control.

Developing control measures of plant-parasitic nematodes (PPNs) rank high as they cause big crop losses globally. The growing awareness of numerous unsafe chemical nematicides and the defects found in their alternatives are calling for rational molecular control of the nematodes. This control focuses on using genetically based plant resistance and exploiting molecular mechanisms underlying plant-nematode interactions. Rapid and significant advances in molecular techniques such as high-quality genome sequencing, interfering RNA (RNAi) and gene editing can offer a better grasp of these interactions. Efficient tools and resources emanating from such interactions are highlighted herein while issues in using them are summarized. Their revision clearly indicates the dire need to further upgrade knowledge about the mechanisms involved in host-specific susceptibility/resistance mediated by PPN effectors, resistance genes, or quantitative trait loci to boost their effective and sustainable use in economically important plant species. Therefore, it is suggested herein to employ the impacts of these techniques on a case-by-case basis. This will allow us to track and optimize PPN control according to the actual variables. It would enable us to precisely fix the factors governing the gene functions and expressions and combine them with other PPN control tactics into integrated management.

Optimizing Safe Approaches to Manage Plant-Parasitic Nematodes.

Plant-parasitic nematodes (PPNs) infect and cause substantial yield losses of many foods, feed, and fiber crops. Increasing concern over chemical nematicides has increased interest in safe alternative methods to minimize these losses. This review focuses on the use and potential of current methods such as biologicals, botanicals, non-host crops, and related rotations, as well as modern techniques against PPNs in sustainable agroecosystems. To evaluate their potential for control, this review offers overviews of their interactions with other biotic and abiotic factors from the standpoint of PPN management. The positive or negative roles of specific production practices are assessed in the context of integrated pest management. Examples are given to reinforce PPN control and increase crop yields via dual-purpose, sequential, and co-application of agricultural inputs. The involved PPN control mechanisms were reviewed with suggestions to optimize their gains. Using the biologicals would preferably be backed by agricultural conservation practices to face issues related to their reliability, inconsistency, and slow activity against PPNs. These practices may comprise offering supplementary resources, such as adequate organic matter, enhancing their habitat quality via specific soil amendments, and reducing or avoiding negative influences of pesticides. Soil microbiome and planted genotypes should be manipulated in specific nematode-suppressive soils to conserve native biologicals that serve to control PPNs. Culture-dependent techniques may be expanded to use promising microbial groups of the suppressive soils to recycle in their host populations. Other modern techniques for PPN control are discussed to maximize their efficient use.

Photorhabdus spp.: An Overview of the Beneficial Aspects of Mutualistic Bacteria of Insecticidal Nematodes.

The current approaches to sustainable agricultural development aspire to use safer means to control pests and pathogens. Photorhabdus bacteria that are insecticidal symbionts of entomopathogenic nematodes in the genus Heterorhabditis can provide such a service with a treasure trove of insecticidal compounds and an ability to cope with the insect immune system. This review highlights the need of Photorhabdus-derived insecticidal, fungicidal, pharmaceutical, parasiticidal, antimicrobial, and toxic materials to fit into current, or emerging, holistic strategies, mainly for managing plant pests and pathogens. The widespread use of these bacteria, however, has been slow, due to cost, natural presence within the uneven distribution of their nematode partners, and problems with trait stability during in vitro culture. Yet, progress has been made, showing an ability to overcome these obstacles via offering affordable mass production and mastered genome sequencing, while detecting more of their beneficial bacterial species/strains. Their high pathogenicity to a wide range of arthropods, efficiency against diseases, and versatility, suggest future promising industrial products. The many useful properties of these bacteria can facilitate their integration with other pest/disease management tactics for crop protection.

Optimizing Sampling and Extraction Methods for Plant-Parasitic and Entomopathogenic Nematodes.

Plant-parasitic and entomopathogenic nematodes (PPNs and EPNs) are key groups in crop production systems. This study aims at optimizing nematode sampling and extraction methods to benefit integrated pest management (IPM) through (a) management of PPNs and (b) use of EPNs. The impacts of these methods on PPNs and EPNs to achieve cost-effective and efficient IPM programs are presented. The common misuses of sampling and extraction methods are discussed. Professionals engaged in IPM should consider sampling the reliability level in the light of the intended goal, location, crop value, susceptibility, nematode species, and available funds. Logical sampling methodology should be expanded to integrate various factors that can recover extra EPN isolates with differential pathogenicity. It should seek for the best EPN-host matching. Merits of repeated baiting for EPN extraction from soil and sieving for PPN recovery from suspensions are presented. Their extraction values may be modelled to quantify the efficiency of nematode separation. The use of proper indices of dispersion to enhance the biocontrol potential of EPNs or save costs in nematicidal applications is ideally compatible with IPM programs. Selecting an extraction method may sometimes require further tests to find the best extraction method of the existing fauna and/or flora. Cons and pros of modern sampling and extraction techniques are highlighted.

Atorvastatin reduces the plasma lipids and oxidative stress but did not reverse the inhibition of prostacyclin generation by aortas in streptozotocin diabetic rats.

The effect of atorvastatin (Lipitor) on diabetes-induced changes in plasma lipids, oxidative stress and the ability of aortic tissues to generate prostacyclin was studied in streptozotocin diabetic rats. In diabetic rats, plasma total cholesterol, triglycerides and serum glucose significantly increased compared to nondiabetic rats. Atorvastatin administration to diabetic rats did not affect hyperglycemia but significantly reduced plasma total cholesterol and triglycerides compared to diabetic rats. The oxidative stress markers urinary isoprostane, liver thiobarbituric acid reactive substances (TBARS) and plasma protein carbonyl content significantly increased in diabetic rats compared to nondiabetic rats. Atorvastatin admnistration to diabetic rats significantly reduced oxidative stress levels compared to diabetic rats, but urinary isoprostane and liver TBARS remained significantly higher than nondiabetic rats. Prostacyclin (PGI(2)) generation by aortic tissues significantly decreased in diabetic rats compared to nondiabetic rats. Atorvastatin administration to diabetic rats did not reverse that inhibition. These results were discussed in the light of the possible effects of hyperglycemia and statins on NAD(P)H-oxidase and cyclooxygenase-2 activities and the genetic difference between rats and other mammals regarding the level of vascular superoxide dismutase (SOD) activity.

Vitamin C or Vitamin B6 supplementation prevent the oxidative stress and decrease of prostacyclin generation in homocysteinemic rats.

We hypothesize that homocysteinemia causes oxidative stress, decreases the aortic ability to generate prostacyclin and that antioxidants have a protective role. Four groups of eight rats each were fed for 8 weeks the control diet (group A), control diet with folic acid omitted and excess methionine (Me) added to drinking water (group B), diet B + 500 mg/kg of Vitamin C (group C) or diet B + 60 mg/kg Vitamin B6 (group D). The three groups of rats fed folic acid deficient (FD) diets (groups B, C and D) were homocysteinemic as indicated by the significant increase in their serum homocysteine (HC) concentration. Rats fed diet B had oxidative stress as indicated by an increase in serum thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein products (AOPP) and urinary isoprostanes and had a decreased ability of their aortas to generate prostacyclin. Homocysteinemic rats fed a FD diet + Vitamin C (group C) or Vitamin B6 (group D) also had high levels of serum homocysteine but the oxidative stress markers and the ability of their aortas to generate prostacyclin returned to normal. This indicates that the homocysteinemic effect is through an oxidative mechanism and that Vitamin C as a free radical scavenger prevents these effects. Serum Vitamin C and liver glutathione concentrations significantly increased in rats fed excess Vitamin B6 compared to the control or FD rats. This may explain why Vitamin B6 has an antioxidative effect.

Oxidized low-density lipoprotein (LDL) enhances thromboxane A(2) synthesis by platelets, but lysolecithin as a product of LDL oxidation has an inhibitory effect.

Oxidation of low-density lipoprotein (LDL) by copper sulfate led to a significant increase in lysophosphatidylcholine (lyso PC) at the expense of phosphatidylcholine. Incubation of different concentrations of oxidized LDL (oxLDL) (32-650 microg protein/ml) with platelets for 1 h at 37 degrees C increased lyso PC content. The increase was dependent on oxLDL concentration. Incubation of platelets with various concentrations of lyso PC in solution for 5 or 15 min showed that lyso PC percentage was increased in the platelet membrane and the increase was dose dependent. Platelets incubated with various concentrations of lyso PC (2-100 microM) for 5 or 15 min and then triggered with thrombin also showed a significant decrease of thromboxane A(2) (TXA(2)) release as lyso PC concentration reached 10 microM or 6 microM, respectively. The decrease of TXA(2) release was more significant as lyso PC concentration was increased. The present study showed that this inhibition of TXA(2) release by lyso PC was due to 1) inhibition of phospholipase A(2) and the decrease of free arachidonic acid liberation from platelet phospholipid and 2) inhibition of cyclooxygenase. These inhibitory effects of lyso PC were discussed in relation to its effect on membrane fluidity. Lyso PC at concentrations of 30, 50, and 100 microM caused a sudden drop in TXA(2) release and a sudden increase of lactic dehydrogenase loss from the platelets due to their lysis and inhibition of cyclooxygenase enzyme. The present study shows that oxLDL contains high levels of lyso PC that are transferable to the platelets and can weaken their responsiveness to thrombin and decrease TXA(2) release. In our previous study, we found that oxLDL also contained high levels of oxysterols and thiobarbituric acid reactive substances (TBARS), which enhanced platelet reactivity to thrombin and increased TXA(2) release. We conclude that the net effect of oxLDL on platelets will depend on its degree of oxidation and the ratio between oxysterols plus TBARS/lyso PC. Variations in this ratio may explain some of the contradictions cited in the literature concerning the effect of oxLDL on platelet activation.

Cholesterol-rich diets have different effects on lipid peroxidation, cholesterol oxides, and antioxidant enzymes in rats and rabbits.

The objective of this study was to compare the effect of cholesterol feeding of rats and rabbits. The levels of lipid peroxidation products and oxysterols in the plasma of the two species plus the antioxidant enzyme activities in the liver and erythrocytes were measured to explain their different susceptibilities to atherosclerosis. Our study showed that rats are less susceptible than are rabbits to the atherogenic effect of a cholesterol-rich diet because of differences in lipid peroxidation products as well as antioxidant enzymes activities in their livers. In rabbits, cholesterol feeding produced severe hypercholesterolemia (43-fold increase) and increased plasma and liver lipid peroxidation. Total as well as the individual oxysterol contents of 7alpha-, 7beta-hydroxycholesterol, alpha-epoxy, beta-epoxycholesterol, cholestanetriol, 7-keto, and 27-hydroxycholesterol significantly increased in the plasma of hypercholesterolemic (HC) rabbits. Erythrocyte glutathione peroxidase (GSH-Px) activity significantly decreased whereas catalase activity significantly increased in HC rabbits. In rats cholesterol feeding increased the plasma cholesterol only twofold and had no effect on plasma or liver lipid peroxidation. Only 7alpha- and 7beta-hydroxycholesterol increased and no change was observed in any of the antioxidant enzymes activity in the erythrocytes. Although cholesterol feeding caused a 10-fold increase of liver cholesterol as ester in both rats and rabbits, the antioxidant enzyme GSH-Px and catalase activities in the liver significantly increased in rats but significantly decreased in rabbits. The increase of GSH-Px and catalase activities in the liver of cholesterol fed rats could have a protective role against oxidation, thus preventing the formation of lipid peroxidation and oxysterols.

Swallowed foreign body: Is interventional management always required?

A retrospective study of 20 cases diagnosed as "swallowed foreign body" seen over a five-year period (July 1993-June 1998) at Asir Central Hospital was performed. Six (30%) were children and 14 (70%) adults. In the children, five were boys and one was a girl. Objects swallowed included metal nails. coins, hair pins and a chain pendant. In the adult group, eight (57%) were males and six (43%) females. Objects swallowed included sewing needles, sharp blades, pieces of glass, paper clips and gravel. The swallowed foreign body in all the patients passed innocuously through the gastrointestinal tract in two to ten (average 4.7) days. Our method of treatment consisted of giving high fiber diet, Metamucil or lactulose and liquid paraffin. There was no mortality.

Effect of trans fatty acids on calcium influx into human arterial endothelial cells.

BACKGROUND: A recent task force of The American Society for Clinical Nutrition and American Society for Nutritional Sciences recommended in a position paper on trans fatty acids that models be developed to assess the effects of changes in fat intake on disease risk. OBJECTIVE: The objective was to investigate, using human arterial endothelial cells as a model, the influence of trans fatty acids and magnesium on cell membrane composition and on calcium influx into arterial cells, a hallmark of atherosclerosis. DESIGN: Endothelial cells were cultured for 3 d in media with high (adequate) or low (inadequate) amounts of magnesium plus various concentrations of trans,trans linoelaidic; cis,cis linoleic; trans elaidic; oleic; or stearic acids. The cells were then harvested and the fatty acid composition and the amount of (45)Ca(2+) incorporated into the cell was determined. RESULTS: The percentage of fatty acids incorporated into the endothelial cells was proportional to the amount added to the culture medium. Adequate magnesium was crucial in preventing calcium influx into endothelial cells. Without an adequate amount of magnesium in the culture medium, linoelaidic and elaidic acids, even at low concentrations, increased the incorporation of (45)Ca(2+) into the cells, whereas stearic acid and oleic acid did not (P < 0.05). CONCLUSION: Our model indicated that a diet inadequate in magnesium combined with trans fat may increase the risk of calcification of endothelial cells.

Hydrogenated fat high in trans monoenes with an adequate level of linoleic acid has no effect on prostaglandin synthesis in rats.

Our study was designed to determine whether hydrogenated fat high in trans monoenes concentration affected prostaglandin synthesis. Corn oil (CO), butter (B), hydrogenated vegetable oil (HF) and coating fat (CF) were used in this study. These fats were fed to rats for 10 wk at 10 g/100 g diet. The phospholipid (PL) fatty acid content of platelets, aorta and heart was determined by gas liquid chromatography, and the in vitro aorta production of prostacyclin (PGI2) from exogenous or endogenous arachidonic acid (AA) was measured using the radioimmuno-assay (RIA) method. Serum thromboxane B2 (TXB2) released by platelets as thromboxane A2 (TXA2) during incubation of whole blood was also measured by this method. In the group fed CF, AA was significantly lower in the PL of aorta, platelet and heart, and the ratio 20:3(n-9)/20:4(n-6) was greater than in the groups fed CO, B or HF, indicating that the group fed CF was essential fatty acid (EFA) deficient. Although AA was significantly lower in the aorta and platelet PL of the group fed HF compared to the group fed CO, that difference did not affect the amounts of PGI2 or TXB2 produced in these groups. The group fed CF had significantly less PGI2 and TXB2 released by aorta and platelets than the other groups. This was the result of the reduced level of AA and the presence of higher amounts of 20:3(n-9) acid in the PL, which might act as a competitive inhibitor for cyclooxygenase. The aortic production of PGI2 from exogenous AA did not differ among the groups indicating that prostaglandin synthetase was not affected by the dietary fat. We conclude that the consumption of hydrogenated fats high in trans 18:1 acids with adequate amount of linoleic acid had no effect on the amount of thromboxane or prostacyclin produced by platelet or aorta in vitro.

Diagnostic yield in barium enema examination.

Full text is available as a scanned copy of the original print version.

Oxysterols and TBARS are among the LDL oxidation products which enhance thromboxane A2 synthesis by platelets.

In this study, we compared the effects of normal LDL (nLDL) and oxidized LDL (oxLDL) on thromboxane (TXA2) release by platelets triggered by low concentration of thrombin, and we determined which component of oxLDL is responsible for that activation. After oxidation of LDL with copper sulfate, the small molecular weight fraction (< 10 kDa) which was high in TBARS was removed; using Amicon Centriprep-10 concentrator membrane. More than 67% of TBARS in the oxLDL preparation was found in solution while the remaining was covalently attached to the oxLDL particles. OxLDL contained significantly higher levels of oxysterols and TBARS than the nLDL. Platelets preincubated with low concentrations of oxLDL (33-132 micrograms protein/mL) produced significantly higher TXA2 than platelets preincubated with equivalent concentrations of nLDL when triggered with thrombin. Platelets treated with oxLDL also contained significantly higher levels of oxysterols than platelets treated with nLDL. Platelets preincubated with pure cholestanetriol (10 micrograms/mL) contained a high level of cholestanetriol in the membrane, and TXA2 release was significantly increased in these platelets compared to the control platelets. The TBARS in solution also was very potent in enhancing TXA2 release by thrombin-treated platelets. These results indicate that oxysterols and the free TBARS either in solution or covalently attached to the oxLDL particles are partly responsible for the stimulatory effect of oxLDL on TXA2 release by platelets. The present study also showed that this enhancement of TXA2 release was due to activation of phospholipase A2 and to the increase of arachidonic acid liberation from the platelet phospholipids.

Effect of cholesterol-rich diets with and without added vitamins E and C on the severity of atherosclerosis in rabbits.

Oxysterols as oxidation products of cholesterol are considered an atherogenic factor in the development of atherosclerosis in the arteries of cholesterol-fed rabbits. We compared the atherogenic effects of diets enriched either with 0.5% oxidized cholesterol (OC; characterized by high amounts of oxysterols) or with pure cholesterol (PC). The effects of antioxidant vitamins E and C added to the PC diet were also evaluated in view of their antioxidative properties for lipoproteins and cholesterol and how this could affect the severity of atherosclerosis. Four groups of rabbits were fed the following for 11 wk: 1) a nonpurified stock diet, 2) this stock diet plus 0.5% OC, 3) the stock diet plus 0.5% PC, and 4) the stock diet plus 0.5% PC and 1000 mg vitamin E and 500 mg vitamin C/kg diet (PC + antioxidants). The OC and PC diets were equally hyperlipidemic and hypercholesterolemic. The severity of atherosclerotic lesions was highest with the OC diet and lowest with the PC + antioxidants diet. The plasma oxysterol concentration was proportional to the severity of atherosclerosis in all three groups of cholesterol-fed rabbits. beta-Very-low-density-lipoprotein modification was minimized by vitamins E and C as indicated by its polyacrylamide gel electrophoretic pattern and its increased binding to the rabbit liver membrane in vitro. This study indicated that OC and PC were equally atherogenic but that the addition of antioxidants to the PC diet significantly reduced its severity, even when hypercholesterolemia persisted. This indicated that atherogenesis can result from an excessive accumulation of oxidation products of cholesterol in the plasma.

Cholestane-3 beta, 5 alpha, 6 beta-triol stimulates phospholipid synthesis and CTP-phosphocholine cytidyltransferase in cultured LLC-PK cells.

The present study was conducted to examine the effect, if any, of triol on the rate of total or individual phospholipid synthesis by LLC-PK cells in culture. LLC-PK cells were incubated in medium with or without 10 micrograms/ml of 5 alpha-cholestane-3 beta, 5 alpha,6 beta-triol (triol) for 24 h. Triol-treated and control cells were then incubated with medium containing either [14C]glycerol or [32P]phosphate for 1, 6 or 12 hr. In triol-treated cells, the amount of labeled glycerol and [32P]phosphate incorporated into glycerophospholipids and phospholipids (PL), respectively, were higher in triol-treated cells than in control cells, indicating a higher rate of PL synthesis in triol-treated cells. The results also showed that the increase in PL synthesis was higher in magnitude for some PL than others, thus disturbing the ratios among the PL fractions in the cell membrane. CTP-phosphocholine cytidyltransferase activity was greatly enhanced in the cytosolic as well as the particulate fractions of the triol-treated cells, which explains the increase of PC synthesis under triol effect. The rate of [3H]acetate incorporation into the total and free fatty acid fractions was significantly increased in triol-treated cells. The activation of the cytidyl transferase enzyme was related to the enhanced de novo synthesis and cellular uptake of fatty acids in triol-treated cells, which make fatty acids more available in these cells and can upregulate the enzyme. The increased synthesis of phospholipids in the triol cells and the increased level of phospholipid in these cells (as micrograms lipid phosphorus/mg cell protein) observed in our previous study indicate changes in the phospholipid head group composition of the triol cells. These changes can affect several membrane properties and membrane bound enzymes.