Effects of soybean oil emulsion and eicosapentaenoic acid on stress response and immune function after a severely stressful operation.
OBJECTIVE: To investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer. SUMMARY BACKGROUND DATA: It has been reported that safflower oil, rich in n-6 polyunsaturated fatty acid (n-6 PUFA), affects the survival rate of septic animals and decreases the immune function. It has also been reported that the administration of fish oil, in contrast, reduces these stress responses and stress-induced immunosuppression. In humans, the effects of soybean oil emulsion and the administration of EPA on stress response and immune function after surgery have not been established. METHODS: Patients who underwent esophagectomy with thoracotomy were divided into three groups. Seven patients were fed by total parenteral nutrition (TPN) with soybean oil emulsion, which accounted for 20% of total calories. Seven patients were given oral or enteral administration of 1.8 g/day EPA, in addition to TPN with soybean oil emulsion. Nine patients served as the control group; these patients received fat-free TPN. Serum interleukin-6 (IL-6), C-reactive protein, concanavalin A (con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation, natural killer cell activity, and stress hormones were measured. RESULTS: The postoperative level of serum IL-6 was significantly higher in the group receiving soybean oil emulsion than in the fat-free group. Oral or enteral supplementation of EPA with soybean oil emulsion significantly reduced the level of serum IL-6 compared with the patients receiving soybean oil emulsion. Con A- or PHA-stimulated lymphocyte proliferation decreased significantly on postoperative day 7 in all groups of patients. The supplementation of EPA with soybean oil emulsion significantly improved the lymphocyte proliferation and natural killer cell activity on postoperative day 21 compared with the group receiving soybean oil emulsion. CONCLUSIONS: Soybean oil emulsion amplifies, and the supplementation of EPA reduces, the stress response and stress-induced immunosuppression. (+info
Effective method for activity assay of lipase from Chromobacterium viscosum.
A method was devised for activity assay of the lipase [triacylglycerol acyl-hydrolase, EC 188.8.131.52] excreted from Chromobacterium viscosum into the culture medium; olive oil emulsified with the aid of Adekatol 45-S-8 (a non-ionic detergent, the ethoxylate of linear sec-alcohols having chain lengths of 10--16 carbon atoms) was used as the substrate. This method was specifically effective for Chromobacterium lipase acitvity assay, and was approximately twice as sensitive as the conventional method, in which polyvinyl alcohol is used for the emulsification of the substrate. (+info
Leucine metabolism in preterm infants receiving parenteral nutrition with medium-chain compared with long-chain triacylglycerol emulsions.
BACKGROUND: Although medium-chain triacylglycerols (MCTs) may be utilized more efficiently than long-chain triacylglycerols (LCTs), their effect on protein metabolism remains controversial. OBJECTIVE: The aim of the study was to compare the effects of mixed MCT-LCT and pure LCT emulsions on leucine metabolism in preterm infants. DESIGN: Fourteen preterm [gestational age: 30+/-1 wk; birth weight: 1409+/-78 g (x +/- SE)] neonates were randomly assigned to receive, from the first day of life, either a 50:50 MCT-LCT (mixed MCT group; n = 7) or an LCT (LCT group; n = 7) lipid emulsion as part of an isonitrogenous, isoenergetic total parenteral nutrition program. On the fourth day, infants received intravenous feeding providing 3 g lipid, 15 g glucose, and 3 g amino acids kg(-1) x d(-1) and underwent 1) indirect calorimetry and 2) a primed, 2-h infusion of H13CO3Na to assess the recovery of 13C in breath, immediately followed by 3) a 3-h infusion of L-[1-13C]leucine. RESULTS: The respiratory quotient tended to be slightly but not significantly higher in the mixed MCT than in the LCT group (0.96+/-0.06 compared with 0.93+/-0.03). We did not detect a significant difference between the mixed MCT and LCT groups with regard to release of leucine from protein breakdown (B; 309+/-40 compared with 257+/-46 micromol x kg(-1) x h(-1)) and nonoxidative leucine disposal (NOLD; 296+/-36 compared with 285+/-49 micromol x kg(-1) x h(-1)). In contrast, leucine oxidation was greater in the mixed MCT than in the LCT group (113+/-10 compared with 67+/-10 micromol x kg(-1) x h(-1); P = 0.007). Net leucine balance (NOLD - B) was less positive in the mixed MCT than in the LCT group (-14+/-9 compared with 28+/-10 micromol x kg(-1) x h(-1); P = 0.011). CONCLUSION: Mixed MCTs may not be as effective as LCT-containing emulsions in promoting protein accretion in parenterally fed preterm neonates. (+info
The adsorption-induced secondary structure of beta-casein and of distinct parts of its sequence in relation to foam and emulsion properties.
Changes in the secondary structure upon adsorption of beta-casein (betaCN) and of distinct parts of its sequence were investigated by far-ultraviolet circular dichroism in order to find suggested relationships with foam and emulsion-forming and -stabilising properties of the same protein/peptides. A teflon/water interface was used as a model system for foam and emulsion interfaces. The maximum surface loads of beta-casein and its derived peptides were investigated. The main secondary structure element of all samples in solution was the unordered random coil, but upon adsorption ordered structure, especially alpha-helix, was induced. At lower pH more ordered structure was induced, just as at lower ionic strength. Apparently, both hydrophobic and hydrophilic groups influence the change of secondary structure induced at a hydrophobic interface. The results suggest that the hydrophobic C-terminal half of betaCN accounted for the high maximum surface load on teflon, while the N-terminal half of betaCN seemed to be responsible for the secondary structure induction upon adsorption. A relation between the maximum surface load and the foam-stabilising properties was found, but an influence of the secondary structure properties on the foam and emulsion-forming and -stabilising properties was not observed. (+info
Oxidized low-density lipoprotein as a delivery system for photosensitizers: implications for photodynamic therapy of atherosclerosis.
Photodynamic therapy is a promising new strategy in the treatment of cardiovascular diseases. Photodynamic therapy for vascular diseases may be improved by the specific delivery of photosensitizers to the atherosclerotic lesion. In this study, we studied whether oxidatively modified low-density lipoprotein (OxLDL) could be used as a specific carrier for photosensitizers, thereby using the scavenger receptor expressed on macrophages as a target. The photosensitizer aluminum phthalocyanine chloride (AlPc) was incorporated into OxLDL, and its photodynamic effects were studied. Macrophages (RAW 264.7) were incubated with various concentrations of OxLDL-AlPc for different periods. After illumination of the cells with red light, cytotoxicity was observed that was dependent on the time of illumination and incubation. Macrophages incubated with OxLDL-AlPc that were not illuminated revealed no cytotoxicity. The uptake of the OxLDL-AlPc complexes was mediated by scavenger receptors expressed on macrophages. In the presence of the polyanion polyinosinic acid, a specific ligand for scavenger receptors, no cytotoxicity could be observed. Serum incubations of the OxLDL-AlPc complexes revealed that these complexes stay intact after incubation. No redistribution of AlPc to other plasma (lipo-) proteins could be detected, and 80-90% of the AlPc remained associated with the OxLDL particle. These results indicate that OxLDL may function as a specific delivery system for photosensitizers to the scavenger receptors expressed on the macrophages in the atherosclerotic lesion, increasing the beneficial effects of photodynamic therapy for cardiovascular diseases. (+info
Developmental regulation of expression of the D3 dopamine receptor in rat nucleus accumbens and islands of Calleja.
The dopamine D3 receptor (D3R) belongs to the D2 subfamily and is expressed in the rat brain in targets of the mesolimbic dopaminergic system. Little is known about its normal development and control by dopaminergic innervation. We studied developmental expression of D3R in the rat nucleus accumbens (NAC) and islands of Calleja (ISC). At postnatal day (P) 7, D3 binding sites and mRNA were low in both areas. By P14, D3R and mRNA concentrations were close to adult levels in the ISC, whereas, in the NAC, binding increased until 3 months after birth. Cellular concentrations of D3 mRNA in the ISC increased with age in conjunction with a decrease in the number of D3 positive cells. In the NAC, the number of positive cells increased, whereas cellular levels of expression remained unchanged. Neonatal 6-hydroxydopamine lesion caused age-dependent changes in D3R expression. D3 binding sites did not change at P7 or P14, but there was a reduction in the number of D3 mRNA positive neurons accompanied by an increase in cellular levels of D3 mRNA at P14, suggesting that changes occurred in a subset of neurons. Up-regulation of D3 binding sites in NAC and ISC occurred 1 month after the lesion (P35) concomitant with a decrease in cellular levels of D3 mRNA and the number of D3 mRNA positive cells. At 3 months (P90) after the lesion, an increase in D3 mRNA occurred with no change in D3 binding sites. D3R shows region-specific dynamics in receptor/mRNA expression during development and is sensitive to loss of dopamine in early postnatal development. (+info
Doppler sonographic enhancement of hepatic hemangiomas and hepatocellular carcinomas after perflenapent emulsion: preliminary study.
Ultrasonographic microbubble contrast agents improve Doppler signals by increasing blood backscatter. We retrospectively reviewed our experience with perflenapent (EchoGen), an emulsion of liquid dodecafluoropentane, in the evaluation of 13 patients with focal hepatic lesions (10 hemangiomas and six hepatocellular carcinomas). Perflenapent improved the detection of color Doppler flow signals within the lesions. The hemangiomas showed peripheral nonpulsatile signals and the hepatocellular carcinomas showed more diffuse enhancement with both arterial and venous type signals. This preliminary study suggests that perflenapent administration may aid in the sonographic differentiation of these focal lesions. (+info
Hydrolysis of emulsified mixtures of triacylglycerols by pancreatic lipase.
Hydrolysis of the emulsified mixture of short-chain triacylglycerols by porcine pancreatic lipase in the presence of procolipase and micellar sodium taurodeoxycholate has been studied. Increase in the content of tributyrin and trioctanoin in the mixture with triacetin had highly cooperative effects on the formation of the interfacial lipase procolipase complex. Abrupt enhancement of the complex stability was observed in the presence of 0.4-0.6 mol mol-1 of tributyrin or 0.58 mol mol-1 of trioctanoin in the substrate phase. The affinity of lipase towards interfacially bound procolipase for the trioctanoin containing 0.07-0.42 mol mol-1 of triacetin was approximately three times higher than that for pure trioctanoin. The cooperative processes involved in complex formation did not contribute to the affinity of the interfacial lipase/(pro)colipase complex towards substrate molecules and its catalytic activity. (+info