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Vaccine Adjuvants in Immunotoxicology
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Oil-based emulsion adjuvants contain a mixture of oil and aqueous phase which is stabilized with a surfactant. W/O(water/octanol) emulsions provide a strong and long-lasting immune effect. Mineral oil-based emulsions are known to be very efficient; however, they may sometimes cause local reactions with reactive antigens (Aucouturier, Dupuis, and Ganne 2001). Non-mineral oils are well-tolerated, but their immunogenicity is poor. W/O emulsions form a depot at the injection site, thereby causing the antigen to be released slowly. Thus, it may be used to reduce the dose, or the number of doses required for an effective antigen. MF59 is an O/W emulsion adjuvant. Squalene, which is included in its structure, is a triterpenoid hydrocarbon produced abundantly as a precursor of cholesterol and steroid hormones in humans. It is included in the structure of most of the adjuvants due to the fact that it is naturally available in the human body and it is biodegradable. In experimental studies on the less toxic MF59, it was suggested that it was a safe and effective vaccine adjuvant that was well tolerated in humans (Yurdakök and İnce 2008). MF59 has been used for an influenza vaccine for the elderly and young children (Morelli et al. 2012).
Modeling Exposure
Published in Samuel C. Morris, Cancer Risk Assessment, 2020
The quasiequilibrium models are simple in structure but highly data dependent. Concentration factors are estimated in laboratory studies or are derived from ratios of average concentrations of pollutants in the different “compartments” in the field, sometimes taken from unrelated references in the literature (Kaye et al., 1984). Even given this liberal approach to derivation of the parameters for food chain models, the necessary data are often not available for specific chemical contaminants. In these cases, parameters are estimated from correlations with physicoch-emical properties. One such property is the octanol/water partition coefficient (Kow). This is the ratio of a chemical’s concentration in the octanol phase to its concentration in the aqueous phase of a two-phase octanol-water system. Travis et al. (1986) report relationships between Kow and several food chain parameters, based on regression analysis, which they derive from various sources. The distribution coefficient (Kd), the ratio of the concentration in the soil to the concentration in the solute at equilibrium (similar to the Kd in groundwater models), is used in estimating soil concentrations which, in turn, are used to determine plant uptake from soil. It is related to Kow as:
Synthesis of Important Chiral Building Blocks for Pharmaceuticals Using Lactobacillus and Rhodococcus Alcohol Dehydrogenases
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Marion Rauter, Simon Krebs, Gotthard Kunze
De Gonzalo et al. (2007) used recombinant ADH from R. ruber expressed in E. coli as well as whole cells of E. coli harboring the overexpressed protein for 2-octanone reduction in (1) organic solvent at 50% (v/v) and (2) micro-aqueous organic solvent at 99% (v/v) with isopropanol-coupled cofactor regeneration. Under conditions of (1) whole cell biocatalysts were fully active in all tested solvent systems, but showed a continuous decrease of reaction rate upon gradual increase of solvent concentration. Free ADH and whole cells showed high biocompatibility for (2) hydrophobic water-immiscible solvents, such as toluene, cyclohexane and hexane gaining a maximum STY of 1.5 and 2.1 g L−1 h−1 for 2-octanone concentrations of 180 and 120 g L−1, respectively. The product 2-(S)-octanol was obtained with absolute specificity (ee >99%). ADH-A exhibited reasonable activity even with high substrate concentrations of ~2.0 M, which is 10-fold higher compared to previous examples.
Neuroprotective effects of rutin on ASH neurons in Caenorhabditis elegans model of Huntington’s disease
Published in Nutritional Neuroscience, 2022
Larissa Marafiga Cordeiro, Marcell Valandro Soares, Aline Franzen da Silva, Marina Lopes Machado, Fabiane Bicca Obetine Baptista, Tássia Limana da Silveira, Leticia Priscilla Arantes, Felix Alexandre Antunes Soares
Response to 1-octanol was assessed as previously described, with minor modifications [20, 21]. Well-fed worms were transferred to food-free intermediate NGM agar plates to remove any remaining E. coli OP50. After 1 min, the worms were transferred to new food-free NGM agar plates and allowed to adapt for 5 min. The assay consisted of submerging a bristle brush in 30% 1-octanol (dissolved in 100% ethanol, v/v), and placing it in front of a forward-moving worm. The latency time until the backward movement was counted. At least ten worms were analyzed in triplicate, and the means of each triplicate were considered. The experiment was repeated on four different days, thus at least 40 worms were observed in this assay. The third day of the adult stage was chosen, in order to align with previously observed patterns of neurodegeneration of ASH neurons [7].
Clarithromycin laurate salt: physicochemical properties and pharmacokinetics after oral administration in humans
Published in Pharmaceutical Development and Technology, 2019
Bashar A. Alkhalidi, Hatim S. AlKhatib, Mohammad Saleh, Saja Hamed, Yasser Bustanji, Nader Al Bujuq, Naji Najib, Susana Torrado-Susana, Al-Sayed Sallam
Partition coefficients of CLM and CLM-L were determined in an octanol-phosphate buffer system at room temperature. Accurately weighed amounts of CLM or CLM-L were dissolved in 10 mLs of phosphate buffer solutions of different pH values and an equal volume of n-octanol was added. Both phases were pre-saturated with each other. The mixtures were vigorously shaken at 25.0 ± 0.5 °C for 1 h, and then placed in a glass separatory funnel overnight. The aqueous phases were analyzed by HPLC to determine the CLM or CLM-L concentration. The concentration of the n-octanol phase was obtained by determining the difference between the total added amount of the drug and the amount present in the aqueous phase. The apparent partition coefficients were determined from the ratio between the organic and the aqueous concentration of the drug.
Synthesis, screening and nanocrystals preparation of rhein amide derivatives
Published in Journal of Microencapsulation, 2018
Lijiang Chen, Jinfeng Zhang, Jinghong Rong, Yu Liu, Jinghua Zhao, Qingguo Cui, Xin Wang, Xiao Liang, Hao Pan, Hongsheng Liu
The determination method was similar to previously described method (Cao et al.2011). It was determined in water and different pH buffer solutions of pH of 1.2, p6.8, 7.4 and 8.0. The water saturated octanol solution of RAD (2 mL) was added to different solutions (2 mL) in sealed glass vials, respectively. The vials were agitated at 150 rpm for 48 h at 25 °C. After reaching the dissolution equilibrium, the solutions were centrifuged at 13,000 rpm for 10 min to remove the undissolved compounds. Then, the samples were analysed by HPLC. The concentrations of each compound in octanol were measured as C1. The apparent oil/water partition coefficient (P) values were calculated as follows: V1 was the volume of octanol, C2 was the initial concentrations of each compound in water saturated octanol and V2 was the volume of water saturated octanol.