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At least 685 records · Page 38Linked to original sources
PubMed2001

Oral administration of soybean lecithin transphosphatidylated phosphatidylserine improves memory impairment in aged rats.

Soybean lecithin transphosphatidylated phosphatidylserine (SB-tPS) was prepared from soybean lecithin and L-serine by a transphosphatidylation reaction, and its effect on age-related memory impairment was evaluated in rats by the Morris water maze test. Continuous oral administration of SB-tPS (60 mg x kg(-1) x d(-1) for 60 d) to male aged rats (24-25 mo) significantly improved performance in the water maze escape test (P < 0.01 vs. control aged rats) similar to bovine brain cortex-derived phosphatidylserine, which restores cognitive function in patients with senile dementia. SB-tPS also increased acetylcholine release and the Na(+), K(+)-ATPase activity of the synaptosomes prepared from these aged rats to the level in young rats. The nootropic actions of SB-tPS in the present study can be partly explained by the changes in these biochemical activities.

Acetylcholine↗
PubMed1992

SPECT brain imaging in Alzheimer's disease during treatment with oral tetrahydroaminoacridine and lecithin.

Quantitative SPECT brain imaging was performed in five normal subjects and in six ambulatory patients with Alzheimer's disease before the initiation of treatment with tetrahydroaminoacridine (THA) and lecithin. Imaging data were acquired with a single-head SPECT camera and a high-resolution collimator after the intravenous injection of 5 mCi of (p,5n) I-123 IMP. Uptake per pixel in 28 regions of interest in the transverse projection of each study was normalized to uptake per pixel in the cerebellum. Perfusion in the patients with Alzheimer's disease was decreased compared with that of the subjects. Perfusion was decreased greater than 2 SD below the mean in the posterior parietal cortex of 5/6 patients, in the temporal cortex of 3/6 patients, and in the frontal cortex of 2/6 patients with Alzheimer's disease. SPECT imaging was repeated in the six patients after initial titration to peak therapy with oral THA (75 to 200mg per day). The same abnormalities were again seen in the same patients. No dramatic clinical or behavioral change in cerebral perfusion was observed from initial treatment of Alzheimer's disease with THA and lecithin.

Administration, Oral↗
PubMed1980

Effect of steryl glycosides on the phase transition of dipalmitoyl lecithin.

The phase transition of dipalmitoyl lecithin, measured by thermal analysis, was eliminated by the plant sterol, sitosterol, and by the derivatives steryl glucoside and acylated steryl glucoside, which were isolated from soybean lipids.When digitonin was added to dipalmitoyl lecithin-sterol mixtures, in amounts equimolar to sterol, the phase transition of the phospholipid was revealed presumably because of the formation of a sterol complex. When digitonin in molar excess of sterol was added, the endothermic peak disappeared again.

Journal Article↗
PubMed1980

Modification of tobacco mosaic virus by polyornithine and lecithin.

Combined action of polyornithine and lecithin modified tobacco mosaic virus (TMV) virions making them sensitive to ribonuclease (RNase), pronase or Triton X-100. Sedimentational analysis and examination of the fluorescence spectrum revealed that the reaction product obtained after RNase treatments of modified TMV was a three-component complex made of coat protein, polyornithine and lecithin. The minimum requirement for the modification was completely fulfilled by cetyltrimethylammonium bromide, suggesting that a positively charged nitrogen group and an alkyl group of moderate size, C10--18, are necessary components. These components react with the surface region of TMV which is considered to have an important role in connecting coat protein subunits in TMV virions.

Cetrimonium Compounds↗
PubMed1982

Lecithin treatment of cognitively impaired Parkinson's patients.

To test the effects of lecithin on cognitive deficits associated with Parkinson's disease, sixteen elderly and mentally-impaired outpatients with Parkinson's disease participated in a 9-week double-blind placebo-controlled study. Each patient took a daily dose of approximately 32 g of a commercial lecithin preparation containing 25% phosphatidylcholine, or an equivalent amount of powdered skim milk placebo. Marked clinical improvement was not observed, but some indications of a positive treatment effect were obtained on memory, cognition, and motility tests.

Aged↗
PubMed1976

Interaction of apoprotein from porcine high-density lipoprotein with dimyristoyl lecithin. 1. The structure of the complexes.

The morphology and structural organisation of the complexes formed from the apoprotein of porcine high-density lipoprotein and dimyristoyl phosphatidylcholine (lecithin) have been studied using the technique of small-angle X-ray scattering. Scattering measurements made in solvents of varying electron density were interpreted in terms of a scattering-equivalent model for the structure of the complex. This model is described by an oblate ellipsoidal morphology with dimensions at 20 degrees C: major axis 11.0 nm, minor axis 5.5 nm. Within this overall shape the lipid hydrocarbon chains are organised in an apolar core whilst the lipid polar head groups and protein are located in a outer shell 0.85 nm in thickness. The oblate morphology demonstrates that the structure of the complex is directed by the fundamental bilayer organisation of the lecithin. The dimension of the minor axis (5.5 nm) indicates that phospholipid hydrocarbon chains are orientated perpendicular to the interface.

Animals↗
PubMed1990

Dipalmitoylphosphatidylcholine (L-alpha-lecithin) stimulates prostaglandin E production in human amnion.

The effect of dipalmitoylphosphatidylcholine (DPPC, L-alpha-lecithin), a substance not containing arachidonic acid, on prostaglandin E (PGE) production of amniotic membrane was studied. DPPC (3.125-800 micrograms/ml) stimulated PGE production of amniotic membrane (150-200%), suggesting that lecithin, the major surfactant component, is directly involved in the mechanism of human parturition as a stimulator of PGE production.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1999

Interactions of melatonin with membrane models: portioning of melatonin in AOT and lecithin reversed micelles.

The interaction of melatonin with water containing either sodium bis (2-ethylhexyl) sulfosuccinate (AOT) or soybean phosphatidylcholine (lecithin) reversed micelles has been investigated by UV absorption spectroscopy, at a molar ratio of melatonin:surfactant 1:800 for AOT and 1:400 for lecithin reversed micelles, and by varying the water:surfactant molar ratio (R). Our results suggest that in the presence of domains from apolar organic solvent to surfactant and to water, melatonin positions itself in the micellar phase, with a preferential location in the surfactant polar head group domain, independent of the nature of the surfactant and the amount of water encapsulated into the micellar core. Effects are due to the hydrophilic and lipophilic moieties of melatonin. The effectiveness of melatonin as an electron donor and free radical scavenger has been recently recognized. While supporting the hypothesis that melatonin may provide antioxidant protection without the benefit of receptors, present findings may suggest that the molecule could easily scavenge aqueous as well as lipophilic radicals.

Antioxidants↗
PubMed1995

Plasma lecithin: cholesterol acyltransferase and plasma lipolytic activity in preterm infants given total parenteral nutrition with 10% or 20% Intralipid.

The effect of 10% or 20% Intralipid on lipid clearing enzymes, plasma lipids and apoproteins was investigated during the first 5 days after birth in 37 premature infants maintained on total parenteral nutrition; 21 infants received 20% and 16 received 10% Intralipid, respectively. Lipid was infused over a 20-h period at rates of 1, 2 and 3 g/kg/day on consecutive days. Plasma lecithin: cholesterol acyltransferase (LCAT) activity was low and increased significantly (p<0.05) only during infusions of 3 g/kg/day in both groups of infants. Plasma lipolytic activity was generally not affected by the regimen or preparation (10% or 20%) of Intralipid infused, except for higher (p<0.05) levels at 3 g/kg/day of 20% compared with prelipid infusion. Plasma triglyceride concentrations wer similar after 10% or 20% Intralipid, whereas plasma total cholesterol was significantly higher during infusion of 2 and 3 g/kg/day of 10% compared with 20% Intralipid. The efficient clearing of 20% Intralipid might be related to the lower lecithin: triglyceride ration which is compatible with the low LCAT activity of premature infants.

Apolipoproteins A↗
PubMed1999

Treatment of gastric lesions in horses with pectin-lecithin complex.

This study compared the study of a pectin-lecithin complex (Pronutrin) on gastric ulcer healing during an 11 day period in 2 groups of 12 horses each. Twenty-four horses suffering from gastric lesions of differing severity were selected from a larger group of clinical cases on the basis of gastroscopic examination. Both gastric mucosal erosions as well as gastric ulcers were found in the 2 mucosal regions (pars nonglandularis and pars glandularis). The gastric mucosal lesions occurred predominantly in the pars nonglandularis in the vicinity of the margo plicatus. The 24 horses were divided equally into a treated group (Group A) and a control group (Group B). Twelve horses in Group A received Pronutrin, in a dose of 300 g/horse/day over a period of 10 days, whereas horses in Group B received no active substance. Gastroscopic examination was performed on Days 0 and 11. The degree of severity of the gastric erosions or gastric ulcers was evaluated independently in the 2 mucosal regions with the aid of a scoring system. Group A horses showed good acceptance of the product and no side effects were recorded. After the 10 day treatment phase, Group A showed a marked reduction in gastric mucosal lesions or disappearance of lesions, while untreated horses showed no change or, even, a deterioration on Day 11. Statistical calculation of efficacy revealed a highly significant reduction in gastric mucosal lesions in the pars nonglandularis and a significant reduction in gastric mucosal lesions in the pars glandularis in the treated horses. It would appear, however, that the treatment period of 10 days was too short, since the gastric mucosal lesions had often not completely healed in all horses. The results of this study in 24 horses with gastric lesions suggest that a pectin-lecithin complex can have a beneficial effect on the healing of gastric ulcers.

Animals↗
PubMed1987

Effect of egg yolk lecithin on transdermal delivery of bunazosin hydrochloride.

Transdermal delivery of bunazosin HCl and the enhancing effect of egg yolk lecithin were examined using an in-vitro hairless mouse skin preparation and rabbits for in-vivo systemic absorption. The delivery of bunazosin in-vitro was small, but it was significantly enhanced when lecithin was incorporated into the same vehicle. This enhancing effect was confirmed with other drugs in-vitro. The enhancing ability was also seen in-vivo. Very little bunazosin was delivered from a propylene glycol suspension, but levels of 100-200 ng mL-1 were achieved by the incorporation of the lechithin.

Adjuvants, Pharmaceutic↗
PubMed1994

Amphotericin B incorporated into egg lecithin-bile salt mixed micelles: molecular and cellular aspects relevant to therapeutic efficacy in experimental mycoses.

The cellular activities of amphotericin B (AmB) used as Fungizone were compared with those of AmB complexed to either egg lecithin and glycocholate (Egam) or egg lecithin and deoxycholate (Edam). Under conditions in which leakage of K+ from erythrocytes and cultured L cells treated with Fungizone was almost complete, Egam and Edam containing concentrations of AmB severalfold greater than the concentration of AmB in Fungizone had no effect but retained the ability to decrease the level of retention of K+ in fungal cells. Analysis by absorption and circular dichroism spectroscopy demonstrated that when these formulations containing AmB at concentrations of less than 10(-5) M were added to buffer, the AmB dissociated slowly as monomers from Egam or Edam and dissociated rapidly as a mixture of monomers and self-associated species from Fungizone. We propose that in Egam and Edam, the absence of free AmB in the self-associated form reduces the toxicity of AmB to mammalian cells, whereas the presence of monomeric AmB results in the retention of the antifungal activities of these complexes.

Amphotericin B↗
PubMed1971

Lecithin-agar assay for lecithinase antibodies in serum.

A technique for assay of lecithinase antibodies in serum was developed in this laboratory by using a lecithin-agar plate diffusion procedure based on a combination of described plate assays. Egg yolk lipoprotein composed primarily of lecithin was used as a substrate for reaction with free or non-neutralized lecithinase C after incubation of known amounts of lecithinase C with various dilutions of control and test sera. It was found that the size of the reaction zone was a function of enzyme concentration and inversely proportional to the antibody concentration. Accuracy and precision of the assay were determined. In addition, lecithinase antibody levels in sera from experimentally inoculated rats and rabbits and sera from randomly selected human patients were studied.

Agar↗
PubMed1971

Thermal inactivation of poliovirus in the presence of selective organic molecules (cholesterol, lecithin, collagen, and beta-carotene).

Poliovirus type 1 strain LS-a exhibited the typical thermal inactivation pattern observed previously by other investigators for poliovirus strains sensitive to the temperatures used in these experiments. However, when the virus suspension was thermally treated at 121 C for 5 sec in the presence of 2% collagen, a stabilizing effect on the virus was observed. The stabilizing effect in the presence of other food additives, such as cholesterol, lecithin, or beta-carotene, was less dramatic or there was no effect at all. Pretreatment of the cells with the same additives before inoculation induced various changes in the susceptibility of the cells to infection by poliovirus. Lecithin and cholesterol treatment appeared to increase HeLa cell susceptibility to the invading virus, thereby enhancing infectivity. Ultraviolet examination of thermally inactivated virus (121 C) suspensions did not indicate any severe denaturation of the nucleic acid core. Subsequent phenol extraction of the infectious nucleic acid from the heat-inactivated virions revealed that infectious nucleic acid was still present in the denatured heat-treated (62 to 72 C) samples of virion. The immediate past history of treatment of the uninoculated cells appeared to be important, since pretreatment of the cells with cholesterol before inoculation resulted in a noticeable increase in infectivity. In addition, cholesterol-treated uninoculated cell sheets also exhibited an increase in longevity compared to the uninoculated, untreated controls.

Carotenoids↗
PubMed1998

Processing respiratory specimens with C18-carboxypropylbetaine: development of a sediment resuspension buffer that contains lytic enzymes to reduce the contamination rate and lecithin to alleviate toxicity.

The C18-carboxypropylbetaine (CB-18) procedure for processing respiratory specimens for the detection of mycobacteria was shown to provide significant increases in sensitivity by smear and culture. However, the procedure also produced increased contamination, a loss in liquid culture sensitivity, and a reduction in smear specificity. Because of these observations, the toxicity of CB-18 and the nature of the contamination were characterized. Preincubation in 1 mM CB-18 impacted viability in a time-dependent fashion, but the magnitude of the loss was species and isolate dependent. Mycobacterium tuberculosis isolates were the most susceptible, losing 20 to 30% of the CFU within 30 min and 30 to 60% after 3 h, whereas Mycobacterium avium and Mycobacterium fortuitum isolates were unaffected by CB-18. In liquid culture, when the concentration of CB-18 exceeded 5 microg/ml, there was an impact on growth characteristics for the most susceptible M. tuberculosis isolate. In contrast, M. fortuitum isolates were able to grow in 100 microg of CB-18 per ml. In liquid culture, the deleterious effects of CB-18 were enhanced in the presence of antibiotics, whereas growth on solid media was not similarly affected. Supplementation of the resuspension buffer with 0.15% lecithin alleviated toxicity. Initial attempts to modify the CB-18 procedure to control contamination incorporated acids or alkalis; however, losses in culture sensitivity occurred. Studies to identify these contaminants led to the development of a sediment resuspension buffer that contained lytic enzymes to combat contamination and lecithin to alleviate toxicity. This formulation included lysozyme, zymolyase, and Cytophaga and Trichoderma extracts and was seen to reduce contamination to acceptable levels (<5%).

Bacteriological Techniques↗
PubMed1969

Familial plasma lecithin: cholesterol acyltransferase deficiency.

A WOMAN WITH FAMILIAL PLASMA LECITHIN: cholesterol acyltransferase (L.C.A.T.) deficiency showed, like the other reported cases, obvious corneal opacity, proteinuria, and moderate anaemia with a slight haemolytic component. In the plasma the concentrations of free cholesterol, triglycerides, and lecithin were high, and those of esterified cholesterol, lysolecithin, and alphalipoprotein were low. L.C.A.T. activity in plasma was 10% of normal. The heparin-induced lipolytic activity in plasma was reduced. The erythrocyte lipid pattern was abnormal and showed the same pattern as earlier described in L.C.A.T. deficiency.The patient's brother also probably suffered from the disease and died in uraemia. These are the fourth and fifth known patients with L.C.A.T. deficiency, the first one reported in a male, and the first one with a fatal outcome.

Acyltransferases↗
PubMed1990

Tacrine (tetrahydroaminoacridine; THA) and lecithin in senile dementia of the Alzheimer type: a multicentre trial. Groupe Français d'Etude de la Tetrahydroaminoacridine.

OBJECTIVE: To see whether combined treatment with oral tacrine (tetrahydroaminoacridine; THA) and lecithin improves the symptoms of patients with Alzheimer's disease. DESIGN: Multicentre double blind, placebo controlled, random order crossover trial with individual determination of maximum tolerated dosage and four month follow up. SETTING: Outpatient departments at six university neurological centres. PATIENTS: 67 Outpatients (24 men, 43 women) aged 53-81 (mean 66 (SD 7.3)) selected according to the following criteria: probable Alzheimer's disease as defined by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association; absence of mood disorder; mini mental state score lower than 26; availability of a close relative able to complete questionnaires; and informed consent of the patient or his or her closest relative, or both. INTERVENTIONS: Mean of 114 mg tacrine or placebo daily plus 1200 mg lecithin daily given in three divided doses for one four week active treatment period and one four week control period without washout at crossover. MAIN OUTCOME MEASURES: Cognitive state as assessed by Folstein's mini mental state rating scale, behavioural state as assessed by the Stockton geriatric rating scale, and overall state as assessed with a visual analogue scale rated by both the relative and the physician. RESULTS: Compared with placebo tacrine did not improve either the mini mental state score (mean 14.9 (SD 7.3) v 14.8 (7.3)) or the Stockton geriatric score (28.2 (15.7) v 28.7 (17.8)), but a slight and statistically significant improvement occurred in the physician's score on the visual analogue scale (6.3 (10.2) v 11.6 (17.9)). Seven patients dropped out. Six patients were excluded because of acute hepatitis and one withdrew for personal reasons not related to treatment. Two other patients developed acute hepatitis at the end of the eight week crossover trial and another during the follow up study. Twenty patients complained of gastrointestinal side effects. CONCLUSIONS: Neither short term nor long term treatment with oral tacrine at dosages lower than 125 mg/day improves the symptoms of Alzheimer's disease. Moreover, these dosages may induce hepatitis (nine of 67 patients in this series).

Aged↗
PubMed1980

Differential scanning calorimetric studies of the thermotropic phase behavior of membranes composed of dipalmitoyllecithin and mixed-acid unsaturated lecithins.

The lecithins 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) have been synthesized by reacylation of the appropriate lysolecithins with fatty acid anhydrides. These lecithins have been used to make model membranes in mixtures with dipalmitoyllecithin (DPPC), and phase diagrams of the two bilayer systems have been constructed. These diagrams show that there is essentially no gel-state miscibility in the POPC-DPPC bilayers at any composition, and that SOPC-DPPC bilayers show gel-state immiscibility at DPPC concentrations of less than 50 mol%, and partial miscibility above 50 mol% DPPC. Analysis of the POPC-DPPC phase diagram on the assumption of athermal solution in the liquid-crystalline phase shows that the two lipids mix nearly randomly above the phase transition. The liquidus curve of SOPC-DPPC bilayers showed deviations from calculated ideal behaviour, which indicated that there is a small excess tendency for the formation of pairs of like molecules in SOPC-DPPC bilayers in the liquid-crystalline phase. Thus, in the liquid-crystalline phase, SOPC and DPPC do not pack quite as well as do POPC and DPPC.

Calorimetry, Differential Scanning↗