Effect of fatty oil dispersion on oil-containing wastewater treatment
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Summary The effect of fatty acid structure on utilization by Ehrlich ascites tumor cells was studied in vitro . Unesterified palmitate, stearate, oleate, and linoleate were metabolized in a qualitatively similar fashion and at roughly comparable rates. Each of these fatty acids was rapidly taken up by the cells in unesterified form. The amount of free fatty acid taken up during the first few minutes was determined by the molar ratio of fatty acid to albumin in the incubation medium and differed for each fatty acid: stearate > palmitate > oleate > linoleate. This concentration of cell-free fatty acid was then maintained with little or no further change during continued exposure for 1 hr to the same medium. On the other hand, the amounts of free fatty acid oxidized to CO 2 and incorporated into lipid esters increased progressively. The rates of oxidation and esterification were related to the fatty acid-albumin molar ratio in the medium and, thus, to the steady-state concentration of free fatty acid associated with the cells. Radioactive linoleate was oxidized at a somewhat greater rate than the other long-chain free fatty acids. Acetate, β-hydroxybutyrate, octanoate, and laurate were metabolized at considerably lower rates than the long-chain free fatty acids. Pyruvate was oxidized as rapidly as palmitate but was poorly incorporated into cell lipid. Attempts to demonstrate net utilization of lipid esters contained in Ehrlich ascites tumor fluid by the cells in vitro were negative. Radioactive palmitate contained in biologically labeled rat chylomicrons was utilized very slowly relative to unesterified palmitate. These observations support the hypothesis that exogenously supplied free fatty acid is a major source of fat for this tumor cell.
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Summary Introduction It has been proposed that exogenous pulmonary surfactant can be used as a drug delivery system for immunosuppressive agents to the alveolar compartment of the lung while reducing the risk of systemic toxicity. Before using this combination, however, alterations in activity of both substances should be examined. Therefore, this study investigated whether the activity of a natural derived surfactant preparation is changed after it is mixed with cyclosporine A (CsA) or rapamycin (RPM). Methods A surfactant suspension was mixed with CsA or RPM and minimal surface tension of these mixtures was measured in vitro . Surfactant activity was evaluated in vivo by its capacity to restore gas exchange in an established model of surfactant deficiency in rats. CsA–surfactant, RPM–surfactant or surfactant alone was instilled intratracheally and blood gases were measured under standardized ventilatory conditions. Results Minimal surface tension of surfactant–CsA was comparable with that of surfactant alone, whereas minimal surface tension of the surfactant–RPM mixture was increased. In vivo partial arterial oxygen pressure levels increased immediately to prelavage values after instillation of CsA–surfactant, RPM–surfactant and surfactant only and were comparable during the entire study period. Conclusion The activity of a naturally derived surfactant was affected when mixed with RPM but not when mixed with CsA at the used concentrations.
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Natural sheep surfactant, rabbit surfactant, human surfactant, and surfactant TA were compared for in vitro surface properties and for responses of preterm lambs to treatment. Equivalent amounts of sheep, rabbit, and human surfactants were needed to lower the surface tension to less than 10 dynes/cm, whereas four times less surfactant TA similarly lowered the surface tension. Surface-spreading rates were similar for the surfactants. The surface adsorption of the batch of human surfactant tested was much slower than was adsorption of the other surfactants. Ventilation was significantly improved in all surfactant-treated lambs relative to the control lambs, indicating the general efficacy of the surfactant treatments. Overall, surfactant TA had the best in vitro characteristics, yet the preterm lambs treated at birth with surfactant TA had lower PO2 values and higher ventilatory requirements than did the sheep surfactant-treated lambs. The in vivo responses to rabbit surfactant were intermediate between the responses to sheep surfactant and to surfactant TA. Human surfactant resulted in the least effective clinical response. More of the phosphatidylcholine associated with human surfactant and surfactant TA was lost from the alveoli and lung tissue after four hours of ventilation than was lost from sheep or rabbit surfactant-treated lambs. More intravascular radiolabeled albumin leaked into the alveoli of the surfactant TA-treated lambs than sheep or rabbit surfactant-treated lambs. The four surfactants also had different sensitivities to the effects on minimum surface tensions of the soluble proteins present in alveolar washes. The study demonstrates that the range of clinical responses was not predictable based on the in vitro surface properties that we measured.(ABSTRACT TRUNCATED AT 250 WORDS)
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Close spacing bio-surfactant tertiary composite flooding pilot test indicated, compared to tertiary composite surfactant system without adding bio-surfactant, usage of sulphonate surfactant and cost of injected chemical decreased respectively by 1/2 and 30% for bio-surfactant tertiary composite system, which is formed by rhamnoilpid bio-surfactant and sulphonate surfactant. The ultra-low interface tension value between flooding system and crude oil reached 10-3mN/m, and recovery factor for central well site and that for overall area increased by 23. 24% and 16. 34% , respectively.
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We evaluated the validity of using a single fatty acid tracer to assess total plasma long-chain free fatty acid (FFA) kinetics and the relationship between the rate of appearance (Ra) of fatty acids in plasma and the fatty acid composition of adipose tissue triglyceride (TG). A mixture of [13C]-labeled myristate, palmitate, stearate, oleate, and linoleate was infused in healthy men during basal conditions and during conditions that stimulate (epinephrine infusion) and inhibit (insulin infusion) lipolysis of adipose tissue TGs. Calculated total FFA, Ra based on palmitate, oleate, or linoleate tracers, was within 15% of the measured sum of the individual fatty acid Ra under all conditions, whereas stearate and myristate tracers consistently underestimated and overestimated total FFA Ra, respectively. The fatty acid Ra profile closely matched the fatty acid profile of subcutaneous adipose tissue TGs during epinephrine infusion, but not during basal conditions and insulin infusion. Our data support the common practice of using labeled palmitate or oleate as fatty acid tracers for assessing total plasma FFA kinetics and suggest that a source of lipids other than adipose tissue TG release fatty acids into the systemic circulation.
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Fatty Acid Metabolism
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Abstract Palmitate negatively affects insulin secretion and apoptosis in the pancreatic β‐cell. The detrimental effects are abolished by elongating and desaturating the fatty acid into oleate. To investigate mechanisms of how the two fatty acids differently affect β‐cell function and apoptosis, lipid handling was determined in MIN6 cells cultured in the presence of the fatty acids palmitate (16:0) and oleate (18:1) and also corresponding monounsaturated fatty acid palmitoleate (16:1) and saturated fatty acid stearate (18:0). Insulin secretion was impaired and apoptosis accentuated in palmitate‐, and to some extent, stearate‐treated cells. Small or no changes in secretion or apoptosis were observed in cells exposed to palmitoleate or oleate. Expressions of genes associated with fatty acid esterification (SCD1, DGAT1, DGAT2, and FAS) were augmented in cells exposed to palmitate or stearate but only partially (DGAT2) in palmitoleate‐ or oleate‐treated cells. Nevertheless, levels of triglycerides were highest in cells exposed to oleate. Similarly, fatty acid oxidation was most pronounced in oleate‐treated cells despite comparable up‐regulation of CPT1 after treatment of cells with the four different fatty acids. The difference in apoptosis between palmitate and stearate was paralleled by similar differences in levels of markers of endoplasmic reticulum (ER) stress in cells exposed to the two fatty acids. Palmitate‐induced ER stress was not accounted for by ceramide de novo synthesis. In conclusion, although palmitate initiated stronger expression changes consistent with lipid accumulation and combustion in MIN6 cells, rise in triglyceride levels and fatty acid oxidation was favored specifically in cells exposed to oleate. J. Cell. Biochem. 111: 497–507, 2010. © 2010 Wiley‐Liss, Inc.
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