Tardive dyskinesia is an insidious and debilitating extrapyramidal side effect of neuroleptic drug treatment. Recent research has suggested that lecithin has been effective in treating tardive dyskinesia. Lecithin's effects were evaluated under double-blind placebo controlled conditions. Treatment conditions included a placebo control group, a lecithin treatment group, and a no-treatment control group. Subjects in the lecithin group received 60 gms/day of lecithin (33 gms of phosphatidylcholine) . Subjects in the placebo group received a similar mixture which contained no lecithin. Subjects received mixtures for 9-11 days. Treatment effectiveness was determined by subjective, objective, and global evaluations. All subjects were evaluated 3 to 4 days prior to treatment and following 9 to 11 days of treatment.

No description available.

A lecitina de soja é um complexo de fosfolipídeos em óleo de soja, sendo denominada de lecitina de soja comercial. Sua coloração é âmbar, apresenta alta viscosidade, cheiro e gosto característicos. É bastante utilizada como emulsificante, possui características próprias devido a modificações física, químicas ou de processos de obtenção. O presente trabalho teve por objetivo avaliar fisico-quimicamente lecitinas de soja clarificadas, pela adição de peróxido de hidrogênio a 35% (v/v), a temperatura e agitação controladas. Avaliar os aspectos qualitativos e de coloração, para posterior aplicação em leite integral UHT e verificação das características de pó (molhabilidade e insolubilidade). A etapa de clarificação foi planejada experimentalmente, através de um Planejamento Composto Central, cuja lecitina de soja comercial, sem tratamento com peróxido foi analisada quanto à reologia, apresentando comportamento pseudoplástico a 25°C e newtoniano à 50°C. Sua composição de ácidos graxos foi de elevado teor de insaturados conforme análise cromatográfica. A clarificação produziu lecitinas mais claras do que a lecitina comercial e foi selecionada a lecitina clarificada com maior valor de luminosidade (L*) para análise reológica, a qual mostrou mesmos comportamentos reológicos da lecitina comercial, porém com ligeiros aumentos na viscosidade aparente. Resultado das avaliações sobre a coloração foram realizadas, mostrando os efeitos da temperatura, tempo de agitação sob rotação constante e concentrações de H2O2 (%, m/v), obtendo-se colorações mais vermelhas e amarelas, intensas e de tonalidade tendendo ao amarelado. O ponto experimental em que se obteve maior luminosidade, cor branca, foi a 50°C, 520 segundos de agitação e adição de 2,3% de peróxido de hidrogênio, 35% (m/v). Um modelo de cor foi elaborado para predizer quais parâmetros de cor influenciam sobre a cor aparente, para isso foram analisados compostos carotenoides e clorofilas, chegando-se à conclusão que outras substâncias, como substâncias marrons e tocoferóis, se determinadas melhorariam o ajuste. Os resultados das avaliações da qualidade oxidativa das lecitinas clarificadas, mostraram os efeitos das variáveis do planejamento sobre as respostas de índice de saponificação, coeficiente de oxidação, índice de acidez e atividade de água, os resultados mostraram que em condições extremas, foram mantidos bons estados de oxidação lipídica. A aplicação da lecitina mais clarificada no leite mostrou que a cor do leite em pó ficou mais clara. A melhor solubilidade e menor tempo de molhabilidade foram obtidos para concentração adicionada de lecitina igual a 1,0% (m/m) sobre a massa aplicada e as micrografias dos pós mostraram que o aumento no teor de lecitina de soja deixa os grânulos menores e o pó mais granuloso. / Soy lecithin is a complex phospholipid in soybean oil, being called commercial soybean lecithin. Its color is amber, high viscosity, smell and taste characteristic. It is widely used as an emulsifier, has its own characteristics due to physical changes, chemical or production processes. This study aimed to assess physico-chemically clarified soy lecithins, by adding hydrogen peroxide to 35% (v / v), the controlled temperature and agitation. It was considered qualitative aspects and also in color, for later use in UHT whole milk and verification of powder characteristics (wettability and solubility). The clarification step is designed experimentally, using a central composite design, the commercial soybean lecithin without peroxide treatment rheology was analyzed, showing pseudoplastic behavior at 25°C and the Newtonian at 50°C, the composition of fatty acids was higher unsaturated content as chromatographic analysis. Clarification produced lighter than lecithin and commercial lecithin was clarified lecithin selected with higher brightness value (L*) to rheological analysis, which showed the same rheological behavior of commercial lecithin, but with slight increases in apparent viscosity. Reviews staining were performed, showing the effects of temperature under constant stirring rotation time and H2O2 concentration (% w/v) to give more red dyes and yellow, intense tint and tended to yellow. The experimental point was obtained in higher brightness, white color at 50°C was 520 seconds of stirring and addition of 2.3% hydrogen peroxide, 35% (w/v). A color model is designed to predict which color parameters influence on the apparent color, for that were analyzed carotenoids and chlorophyll compounds, coming to the conclusion that other substances, such as brown substances and tocopherols, if certain improve the fit. The evaluation of oxidative quality of clarified lecithins have shown the effects of the design variables on the saponification number of responses, oxidation rate, and acid value of water activity, the results showed that in axial conditions are maintained good oxidation states lipid. The application of more clarified lecithin in milk showed that the color of milk powder became clearer. The best solubility and shorter wettability were obtained for added lecithin concentration equal to 1.0% of the applied mass and the powders micrographs showed that the increase in soy lecithin content leaves the smaller beads and the most granular powder. / Tese (Doutorado)

This thesis describes a study of the aggregational behaviour of egg yolk lecithin (EYL), a natural lecithin, and bile salt mixtures especially with respect to an increase of the ionic strength of the solvent. Mixtures of two amphiphiles with very different spontaneous curvature as EYL lecithin and bile salt form mixed micelles and vesicles in aqueous solution. Their properties have been well-studied under physiological conditions, i.e. 150 mM electrolyte concentration and pH 7- 8, while other conditions are still hardly explored. Upon increasing ionic strength the formed structures and the transitional pathways (micelles, coexistence of micelles and vesicles, and vesicles) change the generated structures completely from those observed under physiological conditions. We quantitatively determined these structures formed in a broad range of electrolyte concentrations with various scattering techniques, x-ray, light and neutron scattering and calorimetry. With calorimetry, phase diagrams in the EYL and bile salt concentration phase plane were determined at various ionic strength ranging from physiological salt concentration to up to 1000 mM. Additionally a new electrochemical approach using functionalised electrodes, i.e. sensitive and selective to bile salt, and thus to control the bile salt concentration in solution (concentrations below the critical micellar concentration (cmc)) was attempted, since bile salt removal or injection drives the micelle-to-vesicle or the vesicle-to-micelle transition, respectively, of the mixed aggregational system of EYL/bile salt. Although this control was not achieved within the framework of this thesis, promising results show directions for future experiments.

Lecithin:cholesterol acyltransferase (LCAT) was isolated from hog plasma and basic physicochemical properties and functionally important regions were investigated. Approximately one milligram of the enzyme was purified to apparent homogeneity with approximately a 20,000-fold increase in specific activity. In the plasma, hog LCAT was found to associate with high-density lipoproteins (HDL) probably through hydrophobic interactions with apolipoprotein A-I. HDL was the preferred lipoprotein substrate of the enzyme as its macromolecular substrate. The enzyme was found to contain 4 free sulfhydryl groups; at least one of these appeared to be essential for catalytic activity. The enzyme had a tendency to aggregate at high concentrations. More than half of the tryptophan and none of the tyrosine residues of the enzyme were shown to be exposed to the aqueous environment based on fluorescence and absorbance studies, respectively.

No description available.

Purpose: This thesis aimed to gain a better understanding of the effects of salts in modifying in vitro phase behaviour of lecithin and cholesterol solid implants and to obtain further information on in vitro protein release and stability. Methods: Raman spectroscopy and partial least squares regression (PLSR) were used to investigate lecithin-cholesterol molecular interactions as a function of method of preparation. Lipid-salt interactions were studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectroscopy using principal component analysis (PCA). In vitro release of bovine serum albumin (BSA), a model protein, from lecithin and lecithin:cholesterol implants comprising 10 and 30% NaCl and CaCl₂ were performed. Size exclusion (SE) HPLC was used for quantitative and qualitative analysis of the released BSA. On hydration, changes in phase behaviour and implant morphology were studied by ATR spectroscopy and light microscopy. SE-HPLC, ATR and fluorescence spectroscopy were used to evaluate the structure of unreleased BSA. Protein adsorption on lipid films was studied by flow through ATR spectroscopy. Increased amide II peak area upon recirculation of BSA in salt solutions over hydrated lecithin and lecithin:cholesterol films cast on ZnSe prisms was used to quantify the deposition of BSA onto the lipid surfaces. Results: Shifts in the Raman spectra suggested the lecithin headgroup may be involved in lecithin-cholesterol interactions. Greater R� and root mean square error of cross validation in the calibration curves of physical mixing and heating (120�C) methods reflected poor mixing in these preparations. The mean absolute residue and mean Mahalanobis distance values from the physical mixing and granulation methods indicated their spectral similarity and comparable level of lecithin-cholesterol interactions. Calcium exhibited stronger affinity for phospholipids than sodium and it induced headgroup hydration and reorganisation upon binding. PCA of ATR spectra was sensitive to cholesterol addition, calcium binding and method of preparation whilst PCA of Raman spectra only differentiated the presence of cholesterol. In vitro release of BSA from implants produced from wet granulation mixtures of lecithin and lecithin:cholesterol in the absence of salt showed retention of a high monomer content and the release profiles were similar to the literature. Cholesterol increased the swelling, induced phase transformation of lecithin and, subsequently, reduced the BSA release. Salts only slightly modified the BSA release from the lecithin implants. In contrast, for lecithin:cholesterol matrices salts greatly enhanced implant swelling, induced the formation of hydrated lecithin of heterogeneous size and inhibited the in vitro BSA release. Analyses of the protein showed increased aggregation of BSA with a high retention of native structure while retained within the swollen matrices. ATR spectra suggested that salts promoted protein adsorption onto hydrated lecithin surfaces and the effects depend on salt types (NaCl > CaCl₂) and concentration (0.1 M > 1.0 M) but not on lecithin:cholesterol surfaces. Conclusion: PLSR and PCA can be used to investigate molecular interactions in the solid lipid matrices. In lecithin:cholesterol implants, salts modified the phase behaviour of lecithin which resulted in enhanced swelling, formation of hydrated lecithin of altered morphology and inhibition of in vitro BSA release.

The century poison ¡§dioxins¡¨ are hydrophobic compounds that can combine with many organic matters and persist in the environment as well as to accumulate in living organisms. Dioxins caused great risk to the health of living organisms and to the entire ecological environment. We had isolated previously one bacterial species, Pseudomonas mendocina NSYSU, which can use pentachlorophenol (PCP) as its sole carbon source and degrade dioxin compounds. In order to study the feasibility of using this bacterial strain to bioremediate an PCDD/Fs polluted site, four microcosm experiment groups were designed to test the degradation efficiency of this strain: sterile soil group, non-sterile soil group, soya lecithin group and non-sterile soil with soya lecithin group. In addition, we also analyzed the shift of community structure of each microcosm by PCR-DGGE. The results show that the soya lecithin group has the highest efficiency to degrade OCDD/OCDF. After fifty days of reaction, the degradation rates of OCDD/OCDF were 62% and 47% respectively. The microbial diversity analysis indicated that the soya lecithin group presented less abundant from the initial stage, but increasing gradually over time. This might related to the formation of micelles in water phase which contained higher concentration of PCDD/Fs dissolved from the soil particles. Therefore, soya lecithin not only can reduce the toxicity of PCDD/Fs, but also can enhance the bioavailability of the organic pollutants to the microorganisms. In conclusion, monitoring the transition of P. mendocina NSYSU as well as the microbial diversity can provide valuable information during the bioremediation process by applying soya lecithin.

Purpose: This thesis aimed to gain a better understanding of the effects of salts in modifying in vitro phase behaviour of lecithin and cholesterol solid implants and to obtain further information on in vitro protein release and stability. Methods: Raman spectroscopy and partial least squares regression (PLSR) were used to investigate lecithin-cholesterol molecular interactions as a function of method of preparation. Lipid-salt interactions were studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectroscopy using principal component analysis (PCA). In vitro release of bovine serum albumin (BSA), a model protein, from lecithin and lecithin:cholesterol implants comprising 10 and 30% NaCl and CaCl₂ were performed. Size exclusion (SE) HPLC was used for quantitative and qualitative analysis of the released BSA. On hydration, changes in phase behaviour and implant morphology were studied by ATR spectroscopy and light microscopy. SE-HPLC, ATR and fluorescence spectroscopy were used to evaluate the structure of unreleased BSA. Protein adsorption on lipid films was studied by flow through ATR spectroscopy. Increased amide II peak area upon recirculation of BSA in salt solutions over hydrated lecithin and lecithin:cholesterol films cast on ZnSe prisms was used to quantify the deposition of BSA onto the lipid surfaces. Results: Shifts in the Raman spectra suggested the lecithin headgroup may be involved in lecithin-cholesterol interactions. Greater R� and root mean square error of cross validation in the calibration curves of physical mixing and heating (120�C) methods reflected poor mixing in these preparations. The mean absolute residue and mean Mahalanobis distance values from the physical mixing and granulation methods indicated their spectral similarity and comparable level of lecithin-cholesterol interactions. Calcium exhibited stronger affinity for phospholipids than sodium and it induced headgroup hydration and reorganisation upon binding. PCA of ATR spectra was sensitive to cholesterol addition, calcium binding and method of preparation whilst PCA of Raman spectra only differentiated the presence of cholesterol. In vitro release of BSA from implants produced from wet granulation mixtures of lecithin and lecithin:cholesterol in the absence of salt showed retention of a high monomer content and the release profiles were similar to the literature. Cholesterol increased the swelling, induced phase transformation of lecithin and, subsequently, reduced the BSA release. Salts only slightly modified the BSA release from the lecithin implants. In contrast, for lecithin:cholesterol matrices salts greatly enhanced implant swelling, induced the formation of hydrated lecithin of heterogeneous size and inhibited the in vitro BSA release. Analyses of the protein showed increased aggregation of BSA with a high retention of native structure while retained within the swollen matrices. ATR spectra suggested that salts promoted protein adsorption onto hydrated lecithin surfaces and the effects depend on salt types (NaCl > CaCl₂) and concentration (0.1 M > 1.0 M) but not on lecithin:cholesterol surfaces. Conclusion: PLSR and PCA can be used to investigate molecular interactions in the solid lipid matrices. In lecithin:cholesterol implants, salts modified the phase behaviour of lecithin which resulted in enhanced swelling, formation of hydrated lecithin of altered morphology and inhibition of in vitro BSA release.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Errata slip inserted. Includes bibliographical references.