Effect of fish oil supplementation and restricted feeding on body fat distribution and blood lipid profile in a rabbit model of castration-induced obesity.

This study investigates the effect of fish oil supplementation and restricted feeding on body fat distribution and blood lipid profile in experimentally induced obesity in rabbits. The trial was carried out with 30 male rabbits, divided into 5 groups of 6 animals each (NC - non-castrated, non-treated, full-diet fed; C100 - castrated, non-treated, full-diet fed; FO100 - castrated, treated with fish oil, full-diet fed; C50 - castrated, non-treated, 50% restricted fed; FO50 - castrated, treated with fish oil, 50% restricted fed). At the end of the experiment, plasma lipids measurement and quantification of fat distribution was performed. The results of this study indicate that fish oil supplementation reduces obesity-associated abnormalities in lipid profile (high-density lipoprotein cholesterol to low-density lipoprotein cholesterol ratio and non-esterified fatty acids) and in body fat distribution in full-diet fed rabbits. Restricted feeding (C50) alone and the combination of restricted feeding and fish oil supplementation (FO50) in particular, has a detrimental effect on the lipid profile despite the marked reduction in intra-abdominal fat.

Estimación del volumen de anestésico local en contacto con el nervio ciático en el bloqueo poplíteo / 3D ultrasound estimation of the effective volume for popliteal block at the level of division

La administración del anestésico local en el tejido conectivo que une los componentes tibial y peroneo del nervio ciático a nivel de su división en el hueco poplíteo produce una distribución muy eficiente de anestésico para conseguir un bloqueo efectivo. Mediante ecografía en 3dimensiones podemos cuantificar este volumen de contacto en una longitud determinada del nervio. Métodos. Se incluyó a 20 pacientes consecutivos programados para cirugía de hallux valgus. En todos los casos se realizó un bloqueo poplíteo ecoguiado en la división del nervio ciático, en abordaje «fuera de plano» con el paciente en decúbito prono. Se administraron 30ml de anestésico local y se evaluó su difusión. Se realizó una adquisición volumétrica del nervio ciático antes e inmediatamente después de finalizar la inyección del fármaco para cuantificar el volumen del nervio ciático y el volumen contenido en el interior del tejido conectivo que envuelve ambos componentes del nervio ciático; todo ello en un segmento de 5cm de nervio. Resultados. Todos los bloqueos fueron efectivos a los 20 min. El volumen de anestésico local contenido en el interior del tejido conectivo fue de 6,8±2,6cm3. De este volumen, 4,4±1,7cm3 se situaban en el halo que envolvía los componentes del nervio y 2,4±1,7cm3 se ubicaban en el interior del nervio ciático o sus componentes. Conclusiones. El volumen en contacto con el nervio ciático puede ser estimado mediante la adquisición volumétrica. Nuestros resultados indican que el volumen para el bloqueo efectivo del nervio ciático a nivel poplíteo quizás se podrá reducir de forma significativa en un futuro (AU)

Local anaesthetic injection between the tibial and commmon peroneal nerves within connective tissue sheath results in a predictable diffusion and allows for a reduction in the volume needed to achieve a consistent sciatic popliteal block. Using 3D ultrasound volumetric acquisition, we quantified the visible volume in contact with the nerve along a 5cm segment. Methods. We included 20 consecutive patients scheduled for bunion surgery. Ultrasound guided popliteal block was performed using a posterior, out of plane approach at the level of división of the sciatic nerve. Thirty ml of mepivacaine 1.5% and levobupivacaine 0.5% were slowly injected while assessing the injection pressure and the diffusion of the local anaesthetic. Volumetric acquisition was performed before and after the block to quantify the the volume of the sciatic nerve and the volume of the surrounding hypoechoic halo contained inside the connective tissue in a 5cm segment. Results. All blocks were successful within 20min after the injection. The total estimated volume contained inside the common connective tissue sheath was 6.8±2.6cm3. Of this, the volume of the halo sorrounding the nerve was 4.4±1.7cm3 and the volume inside the sciatic nerve was 2.4±1.7cm3. Conclusions. The volume of local anaesthetic in close contact with the sciatic nerve can be estimated by volumetric acquisition. Our results suggest that the effective volume of local anaesthetic needed for a successful sciatic popliteal block could be reduced to less than 7ml (AU)

Cost-effectiveness of post-operative cell salvage in total knee arthroplasty. Should we continue to recommend its use today? / Análisis de coste-eficacia del recuperador postoperatorio de sangre de drenajes en cirugía protésica primaria de rodilla. ¿Debemos seguir recomendando su empleo en la actualidad?

OBJECTIVES: Total knee arthroplasty (TKA) has a high transfusion rate. In our protocol, the use of postoperative cell salvage is indicated in patients with contraindications to tranexamic acid (TA). An analysis was performed on the effect of post-operative cell salvage (POCS) regarding transfusion rate and costs in patients undergoing TKA. MATERIAL AND METHODS: A prospective analysis was conducted on 518 patients, of whom 434 received TA, and 84 were contraindicated. The red cell mass, blood volume, and the percentage of lost blood volume were calculated. Incidents associated with the use of post-operative re-perfusion of drained blood and the rate of transfusion were recorded. An analysis was performed on the costs associated with allogeneic transfusion prevention methods. RESULTS: A POCS drain was not inserted in 10 out of the 84 patients not candidates for TA. In the 74 in which it was placed, 158±72ml of red cell mass was reinfused. The allogeneic transfusion rate was 36%, and was 52% in those with no drain inserted. Relative risk of transfusion using POCS was 0.69 (0.41 to 1.16) with an absolute risk reduction of 16% (-8 to 40%). The number needed to treat to avoid allogeneic transfusion was 7. The direct costs to avoid allogeneic transfusion were €1,610. No complications associated with blood re-infusion were observed. CONCLUSIONS: The use of POCS would be required in 7 patients after TKA to avoid one allogeneic transfusion with a cost over 10 times that of a transfusion of red cell concentrates.

Optimización de la hemoglobina preoperatoria en cirugía ortopédica mayor utilizando hierro intravenoso con o sin eritropoyetina. Estudio epidemiológico / Optimizing preoperative haemoglobin in major orthopaedic surgery using intravenous iron with or without erythropoietin. An epidemiologic study

Objetivo: Evaluar la efectividad del tratamiento con hierro intravenoso, solo o asociado a eritropoyetina (rHuEPO), mediante el incremento de hemoglobina (Hb). Como objetivo secundario se analizó la relación del incremento de Hb con los parámetros utilizados para evaluar la anemia. Material y método: Estudio observacional retrospectivo realizado en 2 centros entre enero de 2005 y diciembre de 2009. Se incluyeron pacientes sometidos a cirugía ortopédica electiva con déficit de hierro y que fueron tratados con hierro sacarosa intravenosos solo o asociado a rHuEPO. Se analizó la efectividad del tratamiento mediante la diferencia entre la Hb basal y la Hb previa a la cirugía y se valoró la relación entre los parámetros hematimétricos y del metabolismo del hierro con la efectividad del tratamiento. Resultados: Se incluyeron 412 pacientes que recibieron una mediana de 800 mg de hierro sacarosa. A 125 pacientes (30,4%) se les asoció 2,4 viales de rHuEPO. El incremento de Hb fue de 0,8 (1,1) g/dL en los pacientes tratados con hierro intravenoso y de 1,5 (1,3) g/dL en los que se asoció rHuEPO (p < 0,01). El incremento de Hb en los pacientes tratados con hierro se correlacionó con el porcentaje de hematíes hipocromos (r = 0,52) y el valor del receptor soluble de la transferrina (r = 0,59). Conclusiones: La efectividad del tratamiento con hierro sacarosa en pacientes con déficit de hierro para la optimización de la Hb preoperatoria fue moderada, siendo mayor con la administración adyuvante de eritropoyetina. La determinación de los parámetros funcionales del estado del hierro nos podría guiar para mejorar la efectividad del tratamiento (AU)

Aim: To evaluate the effectiveness of intravenous iron treatment, with or without associated erythropoietin (rHuEPO), measured as haemoglobin (Hb) increase. The relationships between the Hb increase and parameters used to evaluate anaemia were analysed. Material and method: Retrospective observational study carried out in two third-level hospitals between January 2005 and December 2009. The study included patients with iron deficiency anaemia scheduled for elective orthopaedic surgery and treated with intravenous iron sucrose alone or associated with rHuEPO. Treatment efficacy was analysed based on the Hb increase from baseline to just before surgery. Results: A total of 412 patients who received a median of 800 mg of iron sucrose were included; 125 of them (30.4%) additionally received 2.4 vials of rHuEPO. The Hb increase was 0.8 (1.1) g/dL in patients treated with intravenous iron and 1.5 (1.3) g/dL in those additionally given rHuEPO (P < .01). The percentage of hypochromic red blood cells (r = 0.52) and soluble transferrin receptor (r = 0.59) value were significantly correlated to the Hb increase in patients receiving iron. Conclusions: In patients with iron deficiency anaemia, the effectiveness of iron sucrose treatment to optimize Hb before surgery was moderate; adjuvant administration of erythropoietin improved the results. Determination of functional iron status parameters may improve the treatment effectiveness (AU)

Optimizing preoperative haemoglobin in major orthopaedic surgery using intravenous iron with or without erythropoietin. An epidemiologic study.

AIM: To evaluate the effectiveness of intravenous iron treatment, with or without associated erythropoietin (rHuEPO), measured as haemoglobin (Hb) increase. The relationships between the Hb increase and parameters used to evaluate anaemia were analysed. MATERIAL AND METHOD: Retrospective observational study carried out in two third-level hospitals between January 2005 and December 2009. The study included patients with iron deficiency anaemia scheduled for elective orthopaedic surgery and treated with intravenous iron sucrose alone or associated with rHuEPO. Treatment efficacy was analysed based on the Hb increase from baseline to just before surgery. RESULTS: A total of 412 patients who received a median of 800mg of iron sucrose were included; 125 of them (30.4%) additionally received 2.4 vials of rHuEPO. The Hb increase was 0.8 (1.1) g/dL in patients treated with intravenous iron and 1.5 (1.3) g/dL in those additionally given rHuEPO(P<.01). The percentage of hypochromic red blood cells (r=0.52) and soluble transferrin receptor (r=0.59) value were significantly correlated to the Hb increase in patients receiving iron. CONCLUSIONS: In patients with iron deficiency anaemia, the effectiveness of iron sucrose treatment to optimize Hb before surgery was moderate; adjuvant administration of erythropoietin improved the results. Determination of functional iron status parameters may improve the treatment effectiveness.

Dietary supplementation of tetradecylthioacetic acid increases feed intake but reduces body weight gain and adipose depot sizes in rats fed on high-fat diets.

AIM: The pan-peroxisome proliferator-activated receptor (PPAR) ligand and fatty acid analogue tetradecylthioacetic acid (TTA) may reduce plasma lipids and enhance hepatic lipid metabolism, as well as reduce adipose tissue sizes in rats fed on high-fat diets. This study further explores the effects of TTA on weight gain, feed intake and adipose tissue functions in rats that are fed a high-fat diet for 7 weeks. METHODS: The effects on feed intake and body weight during 7 weeks' dietary supplement with TTA ( approximately 200 mg/kg bw) were studied in male Wistar rats fed on a lard-based diet containing approximately 40% energy from fat. Adipose tissue mass, body composition and expression of relevant genes in fat depots and liver were measured at the end of the feeding. RESULTS: Despite higher feed intake during the final 2 weeks of the study, rats fed on TTA gained less body weight than lard-fed rats and had markedly decreased subcutaneous, epididymal, perirenal and mesenteric adipose depots. The effects of TTA feeding with reduced body weight gain and energy efficiency (weight gain/feed intake) started between day 10 and 13. Body contents of fat, protein and water were reduced after feeding lard plus TTA, with a stronger decrease in fat relative to protein. Plasma lipids, including Non-Esterified Fatty Acids (NEFA), were significantly reduced, whereas fatty acid beta-oxidation in liver and heart was enhanced in lard plus TTA-fed rats. Hepatic UCP3 was expressed ectopically both at protein and mRNA level (>1900-fold), whereas Ucp1 mRNA was increased approximately 30-fold in epididymal and approximately 90-fold in mesenteric fat after lard plus TTA feeding. CONCLUSION: Our data support the hypothesis that TTA feeding may increase hepatic fatty acid beta-oxidation, and thereby reduce the size of adipose tissues. The functional importance of ectopic hepatic UCP3 is unknown, but might be associated with enhanced energy expenditure and thus the reduced feed efficiency.

Increased survival by feeding tetradecylthioacetic acid during a natural outbreak of heart and skeletal muscle inflammation in S0 Atlantic salmon, Salmo salar L.

We have previously documented increased survival by feeding tetradecylthioacetic acid (TTA) during a natural outbreak of infectious pancreatic necrosis in post-smolt S1 Atlantic salmon. The aim of the present study was to test the effects of dietary TTA in S0 smolt at a location where fish often experience natural outbreaks of heart and skeletal muscle inflammation (HSMI) during their first spring at sea. The experimental groups were fed a diet supplemented with 0.25% TTA for a 6-week period prior to a natural outbreak of HSMI in May 2007. Relative percent survival for the groups fed TTA was 45% compared with control diets, reducing mortality from 4.7% to 2.5%. Expression of genes related to lipid oxidation was higher in cardiac ventricles from salmon fed TTA compared with controls. In addition, salmon fed TTA had periodically reduced levels of plasma urea, and increased cardiosomatic index and growth. Reduced mortality and increased growth after administration of TTA may be related to a combination of anti-inflammatory effects, and an altered metabolic balance with better protein conservation because of increased lipid degradation.

Does the capacity for energy utilization affect the survival of post-smolt Atlantic salmon, Salmo salar L., during natural outbreaks of infectious pancreatic necrosis?

If osmotic stress and reduced seawater tolerance are predisposing factors for infectious pancreatic necrosis (IPN) outbreaks in farmed Atlantic salmon, increased survival by enhancing access to energy would be expected. The aim of the present study was, therefore, to increase energy access in 1-year old Atlantic salmon after sea transfer by increasing the level of dietary fat, by exchanging some of the dietary oil with more easily oxidized medium chain triacylglycerols, or by dietary supplementation of potentially energy enhancing additives such as clofibrate and tetradecylthioacetic acid (TTA). A natural outbreak of IPN occurred 8 weeks after sea transfer, and a significant dietary effect explaining 76% of the variation in mortality was observed. Relative percentage survival for the fish fed TTA in sea water was 70% when compared with the unsupplemented control, reducing mortality from 7.8 to 2.3%. Muscle fat content and plasma chloride were related to IPN mortality, suggesting that reduced hypoosmoregulatory capacity might be a predisposing factor to the onset of an IPN outbreak. Based on the observation of a threefold increase in white muscle mitochondrial fatty acid oxidizing activity by TTA, it is suggested that TTA has resulted in a re-allocation of dietary fatty acids from storage to energy producing oxidation.

Effect of 18:1n-9, 20:5n-3, and 22:6n-3 on lipid accumulation and secretion by Atlantic salmon hepatocytes.

We have studied the effects of dietary FA on the accumulation and secretion of [3H]glycerolipids by salmon hepatocytes in culture. Atlantic salmon were fed diets supplemented with either 100% soybean oil (SO) or 100% fish oil (FO), and grew from an initial weight of 113 +/- 5 g to a final weight of 338 +/- 19 g. Hepatocytes were isolated from both dietary groups and incubated with [3H]glycerol in an FA-free medium; a medium supplemented with 0.75 mM of one of three FA-18:1 n-9, 20:5n-3, or 22:6n-3--or a medium supplemented with 0.75 mM of the sulfur-substituted FA analog tetradecylthioacetic acid (TTA), which cannot undergo beta-oxidation. Incubations were allowed to proceed for 1, 2, 6, or 24 h. The rate of the secretion of radioactive glycerolipids with no FA added was 36% lower from hepatocytes isolated from fish fed the FO diet than it was from hepatocytes isolated from fish fed the SO diet. Hepatocytes incubated with 18:1 n-9 secreted more [3H]TAG than when incubated with no FA, whereas hepatocytes incubated with 20:5n-3 or TTA secreted less labeled TAG than when incubated with no FA. This observation was independent of the feeding group. Hepatocytes incubated with 22:6n-3 secreted the highest amounts of total [3H]glycerolipids compared with the other treatments, owing to increased secretion of phospholipids and mono- and diacylglycerols (MDG). In contrast, the same amounts of [3H]TAG were secreted from these cells as from cells incubated in an FA-free medium. The lipid-lowering effect of FO is thus independent of 22:6n-3, showing that 20:5n-3 is the FA that is responsible for the lipid-lowering effect. The ratio of TAG to MDG in lipids secreted from hepatocytes to which 20:5n-3 or TTA had been added was lower than that in lipids secreted from hepatocytes incubated with 18:1 n-9 or 22:6n-3, suggesting that the last step in TAG synthesis was inhibited. Morphometric measurements revealed that hepatocytes incubated with 20:5n-3 accumulated significantly more cellular lipid than cells treated with 18:1n-9, 22:6n-3, TTA, or no treatment. The area occupied by mitochondria was also greater in these cells. The present study shows that dietary FO reduces TAG secretion from salmon hepatocytes and that 20:5n-3 mediates this effect.

Ferrous fumarate deteriorated plasma antioxidant status in patients with Crohn disease.

BACKGROUND: Iron deficiency anaemia is a frequent complication of Crohn disease. Treatment with ferrous iron (Fe2-) compounds is often unsatisfactory and is associated with gastrointestinal side effects. Theoretically, oral iron supplementation may even be harmful, because iron may reinforce intestinal inflammation by catalysing production of reactive oxygen species. We investigated the effect of ferrous iron on disease activity and plasma antioxidant status in patients with active Crohn disease. METHODS: Ten patients with Crohn disease and iron deficiency and 10 healthy controls were given ferrous fumarate 120 mg for 7 days. The Crohn Disease Activity Index, gastrointestinal complaints and blood samples for antioxidant status, anaemia, inflammation and iron absorption were investigated on day 1 and day 8. RESULTS: During 1 week of ferrous fumarate supplementation, the Crohn Disease Activity Index tended to increase (P = 0.071). Patients experienced aggravation of diarrhoea, abdominal pain and nausea. Plasma-reduced cysteine was lower (P = 0.038) in patients than it was in controls. One week of ferrous iron supplementation further decreased reduced cysteine (P < 0.001) and significantly decreased plasma-reduced glutathione (P = 0.004) in the patients. Serum iron increased significantly in patients after an oral iron load test (from 5.8 +/- 3.2 micromol/L to 30.9 +/- 13.1 micromol/L). CONCLUSIONS: Treatment of iron deficiency with ferrous fumarate deteriorated plasma antioxidant status and increased specific clinical symptoms in patients with active Crohn disease. Plasma reduced cysteine may be a sensitive indicator for oxidative stress in the intestine.

Tetradecylthioacetic acid reduces stenosis development after balloon angioplasty injury of rabbit iliac arteries.

BACKGROUND: tetradecylthioacetic acid (TTA) is a synthetic long-chain fatty acid analogue that inhibits the oxidative modification of low-density lipoprotein particles in vitro. We examined the influence of TTA on the arterial wall response after balloon angioplasty injury in a rabbit iliac model. METHODS AND RESULTS: 14 rabbits were randomized to receiving either TTA fatty acids 800 mg daily perorally (weight 3.6+/-0.1 kg) or to normal diet (weight 3.5+/-0.5 kg, P=NS). Angioplasty was performed via right carotidotomy on both iliac arteries using an oversized balloon catheter, the TTA group being pretreated for 3 weeks. After angioplasty, the lumen diameter was 2.37+/-0.18 versus 2.36+/-0.13 mm for the TTA and control groups, respectively (P=NS). At 10 weeks follow-up angiography, minimal luminal diameter was 1.64+/-0.27 versus 1.13+/-0.52 mm for the TTA and control groups respectively (P<0.05). Histomorphometry did not show significant differences in intimal hyperplasia between the two groups (maximal intimal thickness 0.22+/-0.04 versus 0.19+/-0.10 mm, P=NS and intimal area 0.32+/-0.12 versus 0.36+/-0.23 mm(2), P=NS for the TTA and the control groups, respectively). In the heart, the sum of the n-3 fatty acids was 8.9+/-2.7 in the TTA group versus 4.3+/-0.2 mol% in the control group (P<0.05). The anti-inflammatory fatty acid index, calculated as (22:5 n-3+22:6 n-3+20:3 n-6)/20:4 n-6, was 0.76+/-0.10 vs. 0.25+/-0.03 for the TTA and control groups, respectively (P<0.05). In vitro TTA (100 microM) reduced the proliferation of human smooth muscle cell by more than 50%. CONCLUSION: treatment with TTA is associated with positive arterial remodeling after angioplasty injury. The significance of the in vitro inhibition of human smooth muscle cell proliferation needs to be further elucidated.

Virological and immunological effects of antioxidant treatment in patients with HIV infection.

BACKGROUND: Intracellular oxidative stress in CD4+ lymphocytes due to disturbed glutathione homeostasis may lead to impaired lymphocyte functions and enhanced HIV replication in patients with HIV infection, especially in those with advanced immunodeficiency. The aim of the present study was to assess whether short-term, high-dose antioxidant treatment might have effects on immunological and virological parameters in patients with HIV infection. MATERIALS AND METHODS: In this pilot study, we examined virological and immunological effects of antioxidant combination treatment for 6 days with high doses of N-acetylcysteine (NAC) and vitamin C in 8 patients with HIV infection. The following were assayed before, during and after antioxidant treatment: HIV RNA plasma levels; numbers of CD4+, CD8+, and CD14+ leukocytes in blood; plasma thiols; intracellular glutathione redox status in CD4+ lymphocytes and CD14+ monocytes; lymphocyte proliferation; lymphocyte apoptosis and plasma levels of tumour necrosis factor (TNF)alpha; soluble TNF receptors and neopterin in plasma. RESULTS: No significant changes in HIV RNA plasma levels or CD4+ lymphocyte counts in blood were noted during antioxidant treatment in the patient group. However, in the 5 patients with the most advanced immunodeficiency (CD4+ lymphocyte counts < 200 x 106 L(-1)), a significant rise in CD4+ lymphocyte count, a reduction in HIV RNA plasma level of 0.8 log, an enhanced lymphocyte proliferation and an increased level of intracellular glutathione in CD4+ lymphocytes were found. No change in lymphocyte apoptosis was noted. CONCLUSIONS: Short-term, high-dose combination treatment with NAC and vitamin C in patients with HIV infection and advanced immunodeficiency lead to immunological and virological effects that might be of therapeutic value.

Decreased vitamin A levels in common variable immunodeficiency: vitamin A supplementation in vivo enhances immunoglobulin production and downregulates inflammatory responses.

BACKGROUND: Vitamin A has a broad range of immunological effects, and vitamin A deficiency is associated with recurrent infections. Common variable immunodeficiency (CVI) is a group of B-cell deficiency syndromes with impaired antibody production and recurrent bacterial infections as the major manifestations, but the immunological dysfunctions may also include T cells and macrophages. In the present study we examined the possible role of vitamin A deficiency in CVI. PATIENTS AND METHODS: We analysed plasma vitamin A levels in 20 CVI patients and 16 controls, and examined the relationships between vitamin A and clinical, immunological and metabolic parameters in CVI. In the six CVI patients with the lowest vitamin A levels we also studied the effect of vitamin A supplementation in vivo on several immunological functions in these patients. RESULTS: (i) The majority of CVI patients had decreased vitamin A levels compared with healthy controls, as found in both cross-sectional and longitudinal testing. (ii) Low vitamin A levels were associated with the occurrence of chronic bacterial infections and splenomegaly as well as high neopterin levels. Decreased levels of carrier protein and malabsorption were not observed. (iii) Vitamin A supplementation in patients with low vitamin A levels resulted in increased interleukin-10 (IL-10) and decreased tumour necrosis factor-alpha (TNFalpha) levels, as found in both plasma and monocyte supernatants, possibly favouring anti-inflammatory net effects. (iv) Vitamin A supplementation in vivo also enhanced anti-CD40-stimulated IgG production, serum IgA levels and phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cell (PBMC) proliferation. CONCLUSION: A considerable subgroup of CVI patients appears to be characterized by low vitamin A levels. Our findings support a possible role for vitamin A supplementation in CVI, perhaps resulting in enhanced immunoglobulin synthesis and downregulated inflammatory responses.

Lipid peroxidation of isolated chylomicrons and oxidative status in plasma after intake of highly purified eicosapentaenoic or docosahexaenoic acids.

Fourteen healthy male volunteers were given two separate high-saturated-fat meals with and without the addition of 4 g highly purified ethyl esters of either eicosapentaenoic acid (EPA) (95% pure, n = 7) or docosahexaenoic acid (DHA) (90% pure, n = 7) supplied as 1-g capsules each containing 3.4 mg vitamin E. The chylomicrons were isolated 6 h after the meals, at peak concentrations of n-3 fatty acids (FA). Addition of n-3 FA with the meal caused a 10.4-fold increase in the concentration of n-3 FA in chylomicrons compared to the saturated fat meal without addition of n-3 FA. After the saturated-fat meal, the concentration of thiobarbituric acid-reactive substances (TBARS) was 327.6 +/- 34.6 nmol/mmol triacylglycerol (TAG), which increased to 1015.8 +/- 212.0 nmol/mmol TAG (P < 0.0001, n = 14) after EPA and DHA were added to the meal. There was no significant correlation between the concentrations of TBARS and vitamin E in the chylomicrons collected 6 h after the test meal. The present findings demonstrate an immediate increase in chylomicron peroxidation ex vivo provided by intake of highly purified n-3 FA. The capsular content of vitamin E was absorbed into chylomicrons, but the amount of vitamin E was apparently not sufficient to protect chylomicrons against lipid peroxidation ex vivo. Daily intake of 4 g n-3 FA either as EPA or DHA for 5 wk did not change the plasma concentration of TBARS. Although not significantly different between groups, DHA supplementation decreased total glutathione in plasma (P < 0.05) and EPA supplementation increased plasma concentration of vitamin E (P < 0.05). The other lipid-soluble and polar antioxidants in plasma remained unchanged during 5 wk of intervention with highly purified n-3 FA.

Low doses of eicosapentaenoic acid, docosahexaenoic acid, and hypolipidemic eicosapentaenoic acid derivatives have no effect on lipid peroxidation in plasma.

It was of interest to investigate the influence of both high doses of eicosapentaenoic acid (EPA) and low doses of 2- or 3-methylated EPA on the antioxidant status, as they all cause hypolipidemia, but the dose required is quite different. We fed low doses (250 mg/d/kg body wt) of different EPA derivatives or high doses (1500 mg/d/kg body wt) of EPA and DHA to rats for 5 and 7 d, respectively. The most potent hypolipidemic EPA derivative, 2,2-dimethyl-EPA, did not change the malondialdehyde content in liver or plasma. Plasma vitamin E decreased only after supplementation of those EPA derivatives that caused the greatest increase in the fatty acyl-CoA oxidase activity. Fatty acyl-CoA oxidase activity increased after administration of both EPA and DHA at high doses. High doses of EPA and DHA decreased plasma vitamin E content, whereas only DHA elevated lipid peroxidation. In liver, however, both EPA and DHA increased lipid peroxidation, but the hepatic level of vitamin E was unchanged. The glutathione-requiring enzymes and the glutathione level were unaffected, and no significant changes in the activities of xanthine oxidase and superoxide dismutase were observed in either low- or high-dose experiments. In conclusion, increased peroxisomal beta-oxidation in combination with high amounts of polyunsaturated fatty acids caused elevated lipid peroxidation. At low doses of polyunsaturated fatty acids, lipid peroxidation was unchanged, in spite of increased peroxisomal beta-oxidation, indicating that polyunsaturation is the most important factor for lipid peroxidation.

Generalized peroxisomal disorder in male twins: fatty acid composition of serum lipids and response to n-3 fatty acids.

Male, identical twins presented with hypotonia, hypoglycaemia, dysmorphic facies, feeding problems, discoloured stools, hepatomegaly, and nephrolithiasis. Elevated blood levels of very long-chain fatty acids and bile acids suggested a peroxisomal disorder. Plasmalogen biosynthesis in cultured fibroblasts was reduced. Morphologically distinct peroxisomes were undetectable in liver. Twin 1 suffered from nephrocalcinosis and severe infection, and died at 18 months of age. Twin 2 was blind and physically severely retarded with epilepsy, but survived up to the age of 5 years. Studies of the fatty acid composition of serum lipids showed barely detectable values of eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). During long-term treatment with these n-3 fatty acids, started at age 10 months, the fatty acid profile of the serum lipids was improved or normalized. Since n-3 fatty acids are essential elements in normal development, notably of the nervous system, we suggest that treatment with EPA and DHA should be started as early as possible in general peroxisomal disorders.

Effects of Simvastatin and omega-3 fatty acids on plasma lipoproteins and lipid peroxidation in patients with combined hyperlipidaemia.

OBJECTIVES: Patients with combined hyperlipidemia are at increased risk for development of coronary heart disease. The purpose of this study was to evaluate the efficiency and the safety of treatment with Simvastatin and omega-3 fatty acids in patients with this lipid disorder. DESIGN: A double-blind placebo controlled, randomized study evaluating the effects of Simvastatin separately and in combination with omega-3 fatty acids in 41 healthy patients with defined hyperlipidemia. After a 16 weeks dietary run-in period the patients were treated in periods of 5 weeks. RESULTS: As expected Simvastatin (20 mg day[-1]) reduced serum total cholesterol, triacylglycerols, apolipoproteins B and E and increased HDL-cholesterol and apolipoprotein A1. Addition of omega-3 fatty acids (4 g day[-1]) further decreased serum triacylglycerols (P = 0.007), total cholesterol (P = 0.052) and apolipoprotein E (P = 0.035). No significant changes attributable to supplementation of polyunsaturated fatty acids on the content of lipid peroxides in plasma and in the various lipoprotein fractions were observed. CONCLUSIONS: The combined treatment of Simvastatin and omega-3 fatty acids seems to be an efficient and safe alternative for patients with combined hyperlipidemia.

Eicosapentaenoic acid and sulphur substituted fatty acid analogues inhibit the proliferation of human breast cancer cells in culture.

Numerous studies have shown dietary fatty acids to influence the progression of several types of cancers. The purpose of the present investigation was to examine the influence of various types of fatty acids, including omega-3 fatty acids and a new class of hypolipidemic peroxisome proliferating fatty acid analogues, namely the 3-thia fatty acids, on MCF-7 human breast cancer cell growth. 3-thia fatty acids represent non-beta-oxidizable fatty acid analogues in which a sulphur atom substitutes for the beta-methylene group (3-position) in the saturated and unsaturated fatty acids. The effects of increasing concentrations of palmitic acid, tetradecylthioacetic acid (a 3-thia fatty acid), eicosapentaenoic acid, docosahexaenoic acid, and two 3-thia polyunsaturated fatty acids on the proliferation of MCF-7 cells, maintained in serum-free culture, were studied. At the highest concentration of fatty acid used (64 microM) tetradecylthioacetic acid was found to be the most effective of all fatty acids tested in inhibiting cell growth, whilst palmitic acid and docosahexaenoic acid had no significant effect on cell growth. Thus, of the two dietary polyunsaturated omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid, only eicosapentaenoic acid possesses an inhibitory effect on the proliferation of MCF-7 cells. In all cases the inhibitory effect of the fatty acid was found to be reversible. Tetradecylthioacetic acid has been shown to be a potent peroxisome proliferator. It was, therefore, hypothesized that tetradecylthioacetic acid may inhibit the human MCF-7 cell growth by increasing the level of oxidative stress within the cell. However, use of agents which modify the cell's protective apparatus against oxidative stress had no influence on the inhibitory effect of tetradecylthioacetic acid. These experiments indicate that tetradecylthioacetic acid inhibits cell growth by mechanisms which may be independent of oxidative status.

1-(Carboxymethylthio)tetradecane attenuates PDGF- and TPA-induced c-fos mRNA expression and increases the formation of phosphatidylethanolamine with a shift from less to more polar molecular species in C3H/10T1/2 cells.

1-(Carboxymethylthio)tetradecane caused C3H/10T1/2Cl8 and C3H/10T1/2Cl16 to incorporate 10 times more [32P]Pi into diacylphosphatidylethanolamine than control. This 3-thia fatty acid caused a shift in incorporation of 32P-radioactivity into phosphatidylethanolamine species from species with long to species with short HPLC elution times. The increase in 32P-labeling was parallelled by a change in the apparent mass of phosphatidylethanolamine to a higher proportion of molecular species with short elution times than with long elution times. 1-(Carboxymethylthio)tetradecane caused loss of molecular species containing stearoyl groups. These results indicate that culturing the cells with 1-(carboxymethylthio)tetradecane causes looser packing and an increase in fluidity of the diacylphosphatidylethanolamine molecules in the membranes. 12-O-tetradecanoyl phorbol-13-acetate (TPA), platelet-derived growth factor (PDGF)-BB, or PDGF-AA stimulation of 1-(carboxymethylthio)tetradecane-treated cells resulted in decreased maximal levels of c-fos mRNA expression, indicating attenuation of signal transduction. Compared to cells not treated, the levels of both PDGF-alpha and PDGF-beta receptors were lower while GTPase-activating protein and phospholipase C-gamma levels were not altered in C3H/10T1/2Cl8 and C3H/10T1/2Cl16 cells cultured in the presence of 1-(carboxymethylthio)tetradecane. Our data demonstrate that 1-(carboxymethylthio)tetradecane-mediated changes in phospholipid structure and composition may affect PDGF- and TPA-mediated c-fos gene regulation in fibroblasts.

Vitamins C and E interact in juvenile Atlantic salmon (Salmo salar, L.).

A two way regression study was performed to investigate the interactions between vitamins C and E, and the influence of dietary vitamin C on the development of vitamin E deficiency in first feeding Atlantic salmon. The fish were fed three levels of all-rac-alpha-tocopheryl acetate (0, 150, and 300 mg/kg), each with six levels of ascorbate monophosphate (0, 7.5, 15, 30, 45, and 60 mg/kg ascorbic acid equivalents). Vitamin C protected the fish against vitamin E deficiency in a dose dependent manner, as seen from the data on growth, mortality, hematology, and lipid oxidation in the liver, indicated by the concentration of malondialdehyde. Vitamin C did not influence the tissue levels of vitamin E, except in vitamin C deficiency, which induced a large drop in liver vitamin E concentration. The liver level of vitamin C increased in response to supplementation of both vitamins. The results indicate two different interaction mechanisms: a synergistic effect of simultaneous protection of the water and lipid phases against oxidation, and regeneration of vitamin E from the vitamin E radical by ascorbic acid.