卡介苗多糖核酸微乳的研究

目的制备卡介苗多糖核酸(BCG-PSN)微乳。方法采用磷脂为乳化剂,乙醇为助乳化剂,油酸乙酯为油相,用改良三角相图法确定微乳区域,优化BCG-PSN微乳处方组成。结果与结论所制得BCG-PSN微乳澄清透明,性质稳定。     

Interfacial Properties as Stability Predictors of Lecithin-Stabilized Perfluorocarbon Emulsions

ABSTRACT

The purpose of this study was to determine whether the addition of small quantities of minor lecithin components (phosphatidylinositol, phosphatidic acid, lysophosphatidylethanolamine, and cholesterol) and Pluronic F68 to lecithin could improve the stability of lecithin-stabilized perfluorocarbon emulsions. Attempts were made to correlate emulsion stability with interfacial properties (tension and charge). Dynamic interfacial tension was determined using a Teflon Wilhelmy plate method [reported previously (1)]. Emulsions were prepared by microfluidization. Microelectrophoresis was used to measure emulsion droplet charge, and photon correlation spectroscopy and Coulter analysis were used to determine emulsion stability as a function of droplet size. Thermal kinetic accelerated stability testing was conducted. Various droplet size parameters were used to compare emulsion stabilities, and an overall stability ranking, based on these parameters, was obtained for each emulsion. Small quantities of additives altered emulsion stability and these data were correlated with interfacial properties and initial droplet diameters. The addition of cholesterol to lecithin resulted in the most stable perfluorocarbon emulsion.     

中和剂对化妆品中霉菌和酵母菌检测结果的影响

目的探讨卵磷脂和吐温80作为中和剂对化妆品中霉菌和酵母菌检测结果的影响。方法使用虎红培养基和添加中和剂卵磷脂和吐温80的虎红培养基检测市售化妆品和经黑曲霉、白色念珠菌加标的化妆品的霉菌和酵母菌。结果用虎红培养基和卵磷脂、吐温80-虎红培养基分别检测市售化妆品,均未检出黑曲霉、白色念珠菌;检测黑曲霉加标化妆品,添加中和剂后,菌落数增加,差异有统计学意义(t=5.24,P0.05);检测白色念珠菌加标化妆品,添加中和剂后,菌落数增加,差异有统计学意义(t=3.185,P0.05)。结论卵磷脂和吐温80作为中和剂对化妆品中霉菌和酵母菌的检测结果有影响,可提高其检出结果。建议在化妆品检测标准方法中采用添加中和剂的培养基检测霉菌和酵母菌。     

Alterations in plasma lecithin:cholesterol acyltransferase and myeloperoxidase in acute myocardial infarction: Implications for cardiac outcome

Background

The cholesterol esterifying enzyme, lecithin:cholesterol acyltransferase (LCAT), plays a key role in HDL maturation and remodeling. Myeloperoxidase (MPO) may compromise LCAT enzymatic activity. We tested the extent to which plasma LCAT activity is altered in acute myocardial infarction (MI) in conjunction with abnormal MPO levels. We also assessed the impact of LCAT and MPO on newly developed major adverse cardiovascular events (MACE).

Methods

Two-hundred one consecutive patients referred for acute chest pain of whom 134 had MI (95 with ST-elevation) participated. Forty-five new MACE were ascertained during 1203 (range 13–1745) days of follow-up among 185 patients. Plasma LCAT activity was measured using an exogenous substrate assay. MPO mass was assayed by chemiluminescent microparticle immunoassay.

Results

Plasma LCAT activity was decreased by 15%, coinciding with 7-fold increased MPO levels in acute MI patients vs. patients with non-cardiac chest pain (p < 0.001 for both; correlation: r = −0.343, p < 0.001). MI at admission was associated independently with both lower plasma LCAT activity and higher MPO (age- and sex-adjusted odds ratio per 1 SD increment: 0.46 (95% CI, 0.31–0.68), p < 0.001 and 7.58 (95% CI, 3.34–17.11), p < 0.001, respectively). In an analysis with LCAT and MPO together these associations were modestly attenuated. MPO mass (hazard ratio: 1.59 (95% CI, 1.15–2.19), p = 0.004), but not LCAT activity (hazard ratio: 0.87 (95% CI, 0.65–1.19), p = 0.39), predicted newly manifest MACE.

Conclusion

In acute MI patients, plasma LCAT activity is decreased coinciding with increased MPO levels. Higher MPO but not lower LCAT activity prospectively predicts adverse cardiac outcome.     

Phospholipids in human cerebrospinal fluid

Summary Phospholipid fractions in cerebrospinal fluid of normal persons were examined by separation with thin layer chromatography. 100 ml of cerebrospinal fluid were found to contain 22±4 g phospholipid phosphorus, on the average consisting of 12% lysolecithin, 20% sphingomyelin, 42% lecithin, 2% lysocephalin, 3% phosphatidylinositol, 2% phosphatidylserine, 9% phosphatidylethanolamine. 4% of the total phospholipids remained at the origin of the chromatograms, the rest was recovered in yet unidentified fractions.

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Zusammenfassung Phospholipidfraktionen wurden im Liquor cerebrospinalis von Normalpersonen durch Auftrennen mit Dünnschichtchromatographie bestimmt. In 100 ml Liquor wurden 22±4 g Phospholipidphosphor gefunden, davon 12% Lysolecithin, 20% Sphingomyelin, 42% Lecithin, 2% Lysokephalin, 3% Phosphatidylinositol, 2% Phosphatidylserin und 9% Phosphatidyläthanolamin. 4% wurden an der Auftragsstelle gefunden, der Rest in nicht identifizierten Fraktionen. Mit der angewandten Methode war es also möglich, mehr Phospholipidfraktionen als bisher angegeben aufzutrennen.

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List of Abbreviations CSF cerebrospinal fluid - PL phospholipid(s) - tot PL total phospholipids - PLP phospholipid phosphorus - LL lysolecithin (lysophosphatidylcholine) - SM sphingomyelin - L lecithin (phosphatidylcholine) - PI phosphatidylinositol - PS phosphatidylserine - PE phosphatidylethanolamine - LC lysocephalin, including lysophosphatidylethanolamine; lysophosphatidylinositol and lysophophatidylserine - O Origin     

Is surfactant therapy beneficial in the treatment of the term newborn infant with congenital diaphragmatic hernia?

OBJECTIVES: To determine the impact of surfactant replacement on survival, need for extracorporeal membrane oxygenation (ECMO), and chronic lung disease in term infants with prenatally diagnosed congenital diaphragmatic hernia (CDH). STUDY DESIGN: Prenatally diagnosed infants born at > or =37 weeks' gestation with immediate distress at delivery and no other major congenital anomalies, who were enrolled in the CDH Registry, were analyzed. For univariate analysis, chi 2 tests were used for categoric variables and unpaired t tests for nominal variables. Multiple logistic regression was used to calculate adjusted odds ratios. RESULTS: Eligible infants (n = 522) were identified. Demographic variables were similar between the surfactant-treated (n = 192) and nonsurfactant-treated (n = 330) groups, with the exception of race (white, 88.0% vs 71.2%; P =.0007). The use of ECMO and incidence of chronic lung disease were higher (59.8 vs 50.6, P =.04; 59.9 vs 47.6, P =.0066) and survival lower in the surfactant-treated cohort (57.3 vs 70.0, P =.0033). Adjusted logistic regression for use of ECMO, survival, and chronic lung disease resulted in odds ratios inconsistent with an improved outcome associated with surfactant use. CONCLUSIONS: This analysis shows no benefit associated with surfactant therapy for term infants with a prenatal diagnosis of isolated CDH.     

Lipid nano/submicron emulsions as vehicles for topical flurbiprofen delivery

The application of lipid nano/submicron emulsions as topical drug carrier systems for the percutaneous absorption of flurbiprofen was investigated. The lipid emulsions were made up of isopropyl myristate (IPM), soybean oil, or coconut oil as the oil phase, egg lecithin as the predominant emulsifier, and double-distilled water as the external phase. Stearylamine (SA) and deoxycholic acid (DA) also were used to produce positively and negatively charged emulsions. To evaluate the physicochemical properties of the lipid emulsions, particle size by laser light scattering, the image of atomic force microscopy, and relaxation time values by Nuclear Magnetic Resonance (NMR) were determined. The in vitro permeation data showed that incorporation of SA significantly reduced the topical delivery of flurbiprofen. On the other hand, incorporation of DA exhibited no or a negligible effect on drug permeation. Enhancement of drug absorption was observed when adding oleic acid as part of the oil phase. The in vivo topical application of flurbiprofen from selected lipid emulsions showed a similar trend to the in vitro status. Furthermore, the intersubject variability was considerably reduced by lipid emulsions than by aqueous suspensions in both the in vitro and in vivo experiments. The irritant profiles of lipid emulsions showed that IPM elicited higher irritation than soybean oil. The incorporation of oleic acid also produced skin disruption. The results in the present study suggest the feasibility of lipid emulsions for the topical delivery of flurbiprofen.     

Formulation, characterization, and in vitro evaluation of silymarin-loaded lipid microspheres

The objective of our study was to incorporate and evaluate Silymarin, a chemically defined natural hepatoprotective agent, in lipid microstructured systems. Various constituents of lipid microspheres—namely, internal oily core; surfactant such as soyabean lecithin; and cosurfactants such as span 20, tween 20, tween 80, and propylene glycol—were tried in different concentrations to optimize the final formulation characteristics such as globule size range, structural integrity, sustainability, and percent drug-holding capacity. The final formulation (formulation A) was characterized with respect to size and morphology using transmission electron microscopy and laser diffraction technique. The enhanced mean percent release of 56.70 ± 2.03% was observed in 36 hr from silymarin-loaded lipid microspheres (formulation A), as compared to 18.67 ± 0.192% with silymarin solution (formulation B). Thus, a stable delivery system having synergistic hepatoprotective effect of silymarin and soyabean lecithin could successively be produced for passive targeting to the liver.     

Melatonin-loaded lecithin/chitosan nanoparticles: Physicochemical characterisation and permeability through Caco-2 cell monolayers

In this study, the potential of lecithin/chitosan nanoparticles (NPs) as a mucoadhesive colloidal nanosystem for transmucosal delivery of melatonin was investigated. The size, zeta potential and melatonin loading of the lecithin/chitosan NPs were investigated as a function of lecithin type (Lipoid S45, S75 and S100) and chitosan content in the preparation. The NPs were characterised by mean diameter and zeta potential ranging between 121.6 and 347.5 nm, and 7.5 and 32.7 mV, respectively, and increasing with lecithin-negative charge and chitosan content in the preparation. Melatonin loadings were up to 7.1%. All NPs were characterised by prolonged release profiles with an initial burst (approximately 25%), followed by a slow release phase. Approximately 60–70% of melatonin was released in 4 h. The permeability of melatonin was investigated using Caco-2 cells as an in vitro model of the epithelial barrier. Melatonin permeability from an NP suspension prepared with Lipoid S45 lecithin and a lecithin-to-chitosan weight ratio (L/C) of 20:1 (sample C2) was significantly improved compared to the permeability of melatonin from the solution (P < 0.001) and from all other NPs investigated (P < 0.05). The results obtained by the cell viability studies (MTT and LDH leakage assays) showed that C2 NP suspension did not induce plasma membrane damage or decrease cell viability and could be safely applied to Caco-2 cells in the concentration range tested (<400 μg/ml).