Dysregulated serum metabolites in staging of hepatocellular carcinoma.

BACKGROUND: Correct staging of hepatocellular carcinoma (HCC) could help physicians to precisely select treatments for patients, such as surgery, chemotherapy, or their combination. The objective of this study was to explore potential metabolic markers for staging of hepatocellular carcinoma. METHODS: By liquid chromatography with mass spectrometry (LC-MS), the serum metabolic profiles of 60 pathologically confirmed hepatocellular carcinoma (HCC) patients were analyzed using the TNM staging system and Chinese staging system. RESULTS: The serum levels of dihydrocortisol, lysophosphatidylcholine (LPC-18:0), lysophosphatidylethanolamine (LPE-16:0), taurine, uric acid, adipic acid, tetracosatetraenoic acid, and L-octanoylcarnitine differed significantly between staging I and non-stage I HCCs (p < 0.05) based on the HCC TNM staging system, and compared to stage I sera, non-stage I sera contained higher levels of dihydrocortisol, adipic acid, tetracosatetraenoic acid, and L-octanoylcarnitine. There are significant differences were observed in serum levels of LPC (22:6), alpha-linolenylcarnitine, estrone, LPE (16:0), LPE (18:2), and taurine between stage I and stage II HCCs (p < 0.05) based on the Chinese HCC staging system, and compared to stage I sera, stage II sera had a higher level of LPC (22:6). CONCLUSION: These dysregulated metabolites in sera of HCC patients potentially could be used as biomarkers for the clinical staging of HCC.

Development of Kidney Transplant Fibrosis Is Inversely Associated With Plasma Marine Fatty Acid Level.

OBJECTIVE(S): We assessed associations between plasma levels of polyunsaturated fatty acids (PUFAs) and degree of inflammation and interstitial fibrosis in transplanted kidneys. DESIGN: The design of the study was single center cohort study. SUBJECTS: A study population of 156 patients who received a kidney transplant at Oslo University Hospital during 2010. MAIN OUTCOME MEASURE: Kidney transplant biopsies were obtained at 2 months and 1 year after transplantation. Degree of inflammation and interstitial fibrosis in the cortex of transplanted kidneys were estimated semi-quantitatively. Plasma phospholipid fatty acids levels were measured in a stable phase 2 months posttransplant. We used multivariate linear regression to assess associations between plasma levels of PUFAs and degree of inflammation and interstitial fibrosis at 2 months and 1 year postoperatively and change in degree of interstitial fibrosis during the first year after transplantation, adjusting for inflammation and fibrosis risk factors. RESULTS: Higher plasma marine n-3 PUFA levels were associated with less development of interstitial fibrosis in the kidney transplant (unstandardized ß-coefficient -1.12, standardized ß-coefficient -0.18, P = .03) during the first year after transplantation. Plasma levels of alpha linoleic acid, linoleic acid, and arachidonic acid were not associated with development of interstitial fibrosis. No associations were found between plasma levels of PUFAs and inflammation inside fibrotic areas or outside fibrotic areas in the kidney transplant at neither 2 months nor 1 year postoperatively. Linolenic acid levels in plasma were positively associated with change in renal function during the first year after transplantation. CONCLUSION: The inverse association between plasma marine n-3 PUFA levels and development of interstitial fibrosis during the first year after kidney transplantation suggests that marine fatty acid consumption might halt progression of fibrosis.

Association between polyunsaturated fatty acid-derived oxylipid biosynthesis and leukocyte inflammatory marker expression in periparturient dairy cows.

Peripheral blood mononuclear leukocytes from periparturient cows can have exacerbated inflammatory responses that contribute to disease incidence and severity. Oxylipids derived from the oxygenation of polyunsaturated fatty acids (PUFA) can regulate the magnitude and duration of inflammation. Although PUFA substrate for oxylipid biosynthesis in leukocytes is known to change across the periparturient period, the plasma oxylipid profile and how this profile relates to leukocyte inflammatory phenotype is not clear. The objective of this study was to determine if a relationship exists between the profile of pro- and antiinflammatory plasma oxylipids and the inflammatory phenotype of peripheral blood leukocytes during the periparturient period. Seven multiparous Holsteins were sampled from the prepartum period through peak lactation. Plasma oxylipids were measured by liquid chromatography-mass spectrometry, peripheral leukocyte mRNA expression was measured by quantitative PCR, and PUFA content of peripheral blood mononuclear cells was measured by gas chromatography-mass spectrometry. Concentrations of several hydroxyl products of linoleic and arachidonic acid changed over time. Linoleic acid and arachidonic acid concentrations in leukocytes increased during early lactation, suggesting that substrate availability for hydroxyoctadecadienoic and hydroxyeicosatetraenoic acid biosynthesis may influence the oxylipid profile. Leukocyte mRNA expressions of IL-12B, IL-1B, inducible nitric oxide synthase 2, and cyclooxygenase 2 were correlated with several plasma oxylipids. These are the first observations linking leukocyte inflammatory gene responses to shifts in oxylipid biosynthesis in periparturient dairy cows.

Identification and profiling of targeted oxidized linoleic acid metabolites in rat plasma by quadrupole time-of-flight mass spectrometry.

Linoleic acid (LA) and LA-esters are the precursors of LA hydroperoxides, which are readily converted to 9- and 13-hydroxy-​octadecadienoic acid (HODE) and 9- and 13-oxo-​octadecadienoic acid (oxo ODE) metabolites in vivo. These four oxidized LA metabolites (OXLAMs) have been implicated in a variety of pathological conditions. Therefore, their accurate measurement may provide mechanistic insights into disease pathogenesis. Here we present a novel quadrupole time-of-flight mass spectrometry (Q-TOFMS) method for quantitation and identification of target OXLAMs in rat plasma. In this method, the esterified OXLAMs were base-hydrolyzed and followed by liquid-liquid extraction. Quantitative analyses were based on one-point standard addition with isotope dilution. The Q-TOFMS data of target metabolites were acquired and multiple reaction monitoring extracted-ion chromatograms were generated post-acquisition with a 10 ppm extraction window. The limit of quantitation was 9.7-35.9 nmol/L depending on the metabolite. The method was reproducible with a coefficient of variation of <18.5%. Mean concentrations of target metabolites in rat plasma were 57.8, 123.2, 218.1 and 57.8 nmol/L for 9-HODE, 13-HODE, 9-oxoODE and 13-oxoODE, respectively. Plasma levels of total OXLAMs were 456.9 nmol/L, which correlated well with published concentrations obtained by gas chromatography/mass spectrometry (GC/MS). The concentrations were also obtained utilizing a standard addition curve approach. The calibration curves were linear with correlation coefficients of >0.991. Concentrations of 9-HODE, 13-HODE, 9-oxoODE and 13-oxoODE were 84.0, 138.6, 263.0 and 69.5 nmol/L, respectively, which were consistent with the results obtained from one-point standard addition. Target metabolites were simultaneously characterized based on the accurate Q-TOFMS data. This is the first study of secondary LA metabolites using Q-TOFMS. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

jacaric acid, a linolenic acid isomer with a conjugated triene system, reduces stearoyl-CoA desaturase expression in liver of mice.

Conjugated fatty acid is a collective term used for fatty acids with conjugated double bond systems. Seed oils from certain plants include conjugated linolenic acids, which have a conjugated triene system and are geometrical and positional isomers of α-linolenic acid. One of these isomers, jacaric acid (JA, 8c, 10t, 12c-18:3), has not been examined widely. Therefore, we investigated the absorption and metabolism of JA in normal animals (ICR mice). An oral dose of JA of 5 mg/day for 1 week had no effects on body weight, food intake and tissue weight of mice. JA was detected in the serum, kidney, liver, lung and epididymal white adipose tissue. Analysis of the fatty acid composition in liver and white adipose tissue showed a tendency to increase levels of saturated fatty acids (SFAs) such as palmitic acid (16:0) and stearic acid (18:0) and to decrease levels of monounsaturated fatty acids (MUFAs) such as palmitoleic acid (16:1) and oleic acid (18:1). Thus, JA treatment decreased the desaturation index (16:1/16:0, 18:1/18:0) in liver and white adipose tissue. This index is used as an indicator of the activity of stearoyl coenzyme A desaturase (SCD), an endoplasmic reticulum enzyme that catalyzes the biosynthesis of MUFAs from SFAs. The change in this index indicates that JA inhibited SCD activity in ICR mice, and further experiments showed that JA also decreased the expression level of SCD-1 mRNA. Inhibition of SCD activity may have anti-obesity and anti-diabetes effects, and therefore the findings in this study suggest that JA may be effective for preventing obesity and diabetes.

Lipidomic profiling of serum and pancreatic fluid in chronic pancreatitis.

OBJECTIVES: Oxidative stress is intimately involved in the pathogenesis of chronic pancreatitis (CP), and its quantification may represent a useful biomarker. The aim was to determine whether oxidized fatty acid (OxFA) levels in serum and/or pancreatic fluid are elevated in CP. METHODS: Patients evaluated for abdominal pain were classified into 3 groups (controls, mild CP, and severe CP). Serum and secretin-stimulated pancreatic fluid samples were stored under conditions to minimize artificial oxidation. Ten arachidonic and linoleic acid oxidation products were simultaneously measured using liquid chromatography-electrospray ionization-tandem mass spectrometry. RESULTS: Most OxFAs were significantly elevated in the serum of patients with mild and severe CP compared to controls and correlated with structural features on endoscopic ultrasound. For example, the mean (SD) ratio of serum 13-HODE to its precursor linoleic acid was 0.03 (0.004) in controls, 0.06 (0.02) in mild CP, and 0.10 (0.04) in severe CP (analysis of variance, P = 0.004) and had a strong correlation with endoscopic ultrasound features (Spearman r = 0.84, P < 0.001). In the pancreatic fluid, statistically significant increases of OxFA products were observed in mild CP compared to controls. CONCLUSIONS: Oxidized fatty acid products are increased in the serum and pancreatic fluid of patients with CP, suggesting a potential role as biomarkers. ABBREVIATIONS: AA - arachidonic acidANOVA - analysis of varianceAP - acute pancreatitisCP - chronic pancreatitisePFT - endoscopic pancreatic function testEUS - endoscopic ultrasoundHPLC - high-pressure liquid chromatographyHETE - hydroxy-eicosatetranoic acidHODE - hydroxy-octadecadienoic acidLA - linoleic acidLC-ESI-MS/MS - liquid chromatography-electrospray ionization-tandem mass spectrometryM - molarOxFA - oxidized fatty acidsPFT - pancreatic function test.

Chronic and acute effects of walnuts on antioxidant capacity and nutritional status in humans: a randomized, cross-over pilot study.

BACKGROUND: Compared with other common plant foods, walnuts (Juglans regia) are consistently ranked among the highest in antioxidant capacity. In vitro, walnut polyphenols inhibit plasma and LDL oxidation, while in animal models they lower biomarkers of oxidative stress and raise antioxidant capacity. A limited number of human feeding trials indicate that walnuts improve some measures of antioxidant status, but not others. METHODS: A 19 wk, randomized crossover trial was conducted in 21 generally healthy men and postmenopausal women > or = 50 y to study the dose-response effects of walnut intake on biomarkers of antioxidant activity, oxidative stress, and nutrient status. Subjects were randomized to receive either 21 or 42 g raw walnuts/d during each 6 wk intervention phase with a 6 wk washout between phases. Subjects were instructed to consume their usual diet, but refrain from eating any other tree nuts, seeds, peanuts, or ellagitannin-rich foods during the entire study, and other polyphenol-rich foods for 2 d prior to each study visit. RESULTS: Compared to baseline levels, red blood cell (RBC) linoleic acid and plasma pyridoxal phosphate (PLP) were significantly higher after 6 wk with 42 g/d walnuts (P < 0.05 for both). Overall, changes in plasma total thiols, and other antioxidant biomarkers, were not significant with either walnut dose. However, when compared to fasting levels, plasma total thiols were elevated within 1 h of walnut consumption with both doses during the baseline and end visits for each intervention phase (P < 0.05 for all). Despite the observed increase in RBC linoleic and linolenic acids associated with walnut consumption, this substrate for lipid peroxidation only minimally affected malondialdehyde (MDA) and antioxidant capacity. The proportional changes in MDA and Oxygen Radical Absorbance Capacity (ORAC) were consistent with a dose-response effect, although no significant within- or between-group differences were observed for these measures. CONCLUSIONS: Walnut consumption did not significantly change the plasma antioxidant capacity of healthy, well-nourished older adults in this pilot study. However, improvements in linoleic acid and pyridoxal phosphate were observed with chronic consumption, while total plasma thiols were enhanced acutely. Future studies investigating the antioxidant effects of walnuts in humans are warranted, but should include either a larger sample size or a controlled feeding intervention. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00626691.

Depleted red cell membrane essential fatty acids in drug-treated schizophrenic patients.

The fatty acid composition of red blood cell membranes from 23 drug-treated schizophrenic patients was measured and compared with a healthy control group. There were substantial depletions of fatty acids from the n6 and n3 series, particularly arachidonic and docosahexanoic acid. Significant negative correlations between depleted n6 fatty acids and plasma levels of thiobarbituric acid reactive substances suggests that depletion is caused by increased breakdown of these fatty acids rather than by impaired incorporation of fatty acids into membranes. Arachidonic and docosahexanoic acids appear to show a bimodal distribution. We propose that this may be a metabolic abnormality which is of aetiological importance in schizophrenia.

Visual-acuity development in healthy preterm infants: effect of marine-oil supplementation.

Docosahexaenoic acid (DHA; 22:6n-3) is important for normal visual development. We hypothesized that preterm infants fed formulas with marine oil as a source of DHA would have better visual acuity than infants fed formulas without marine oil, as measured by the Teller Acuity Card procedure. Marine oil (P < 0.001) and age (P < 0.0001) influenced visual acuity, by repeated-measures analysis of variance (ANOVA) corrected for the effect of subject. Marine-oil-supplemented infants had better visual acuity than those fed standard formulas at 2 and 4 mo of age, by Fishers' least-squares difference (LSD). Acuity of both dietary groups improved through 6.5 mo of age, then plateaued. Through 4 mo of age, acuity was inversely related to oxygen supplementation (log10 h) and positively related to DHA status, by general-linear-models (GLM) analysis. After 4 mo of age, birth weight and gestational age were the only variables consistently related to visual acuity by GLM. We conclude that marine-oil-supplemented formula improved visual acuity of preterm infants through 4 mo of age by improving DHA status.

Fatty acid metabolism in health and disease: the role of delta-6-desaturase.

Linoleic acid is the main dietary essential fatty acid (EFA). To be fully utilized by the body, it must be metabolized to a range of other substances. The first step in this pathway is delta-6-desaturation to gamma-linolenic acid (GLA). This step is slow and rate-limiting, particularly in humans. If delta-6-desaturation is impaired for any reason, the supply of further metabolites may be inadequate for normal function. If the consumption of further metabolites is excessive, then a normal rate of delta-6-desaturation may be inadequate. In these circumstances the direct supply of GLA or further metabolites may be of value. This concept is illustrated by atopic eczema and diabetes, which may represent inherited and acquired examples of inadequate delta-6-desaturation.

Prolonged retention of doubly labeled phosphatidylcholine in human plasma and erythrocytes after oral administration.

The plasma kinetics of a preparation of dilinoleoyl phosphatidylcholine (DLPC) specifically labeled with 3H in the choline moiety and with 14C in the 2-fatty acid (FA) were evaluated in six healthy volunteers after oral administration. Retention of both isotopes in plasma exceeded expectations, with a half-life in the elimination phase of 172.2 h for 3H and 69.7 h for 14C. Up to 60 d after administration, there were still significant levels of radioactivity present in plasma. The relative stability of the [14C]FA label was demonstrated by the retention for more than 12 h of an isotope ratio close to that of the compound administered. The 14C label of DLPC remained in position-2, as assessed by cleavage of plasma phospholipids with phospholipase A2. The [3H]choline label showed an early incorporation into high density lipoproteins and subsequently into low density lipoproteins (LDL); conversely, the 14C radioactivity was rapidly incorporated into triacylglycerols that were mainly associated with very low density lipoproteins. Radioactivity measurements revealed that both isotopes remained the longest time in LDL. In red blood cell (RBC) lipids, [3H]choline radioactivity accumulated over time, with a plateau after 48 h, whereas FA radioactivity accumulated more rapidly and was followed by a progressive decay. Analysis of the isotope ratio in these cells suggested an early incorporation of lyso products followed by rapid transfer of FA from plasma. The RBC maintained considerable radioactivity for a prolonged time, thus acting as a possible reservoir for the DLPC administered.(ABSTRACT TRUNCATED AT 250 WORDS)

Borage or primrose oil added to standardized diets are equivalent sources for gamma-linolenic acid in rats.

The aim of this study was to evaluate the effect of different doses and sources of dietary gamma-linolenic acid (GLA) on the tissue phospholipid fatty acid composition. Rats fed four different levels of GLA (2.3, 4.6, 6.4 and 16.2 g of GLA/kg diet) in the form of either borage oil or evening primrose oil during 6 wk were compared with animals fed corn oil. The levels of dihomo-gamma-linolenic acid (DHLA) and GLA showed a significant dose-related increase in liver, erythrocyte and aorta phospholipids. Moreover, the arachidonic acid/DHLA ratios in tissues decreased with increasing intake of dietary GLA. There was no significant difference in tissue GLA and DHLA levels within groups given equal amounts of dietary GLA either as borage oil or evening primrose oil. The amount of dietary GLA administered did not significantly influence prostaglandin E2 production in stimulated aortic rings and thromboxane B2 levels in serum; however, an increase in prostaglandin E1 derived from DHLA was observed in the supernatants of stimulated aorta.

Replacement of butter on bread by rapeseed oil and rapeseed oil-containing margarine: effects on plasma fatty acid composition and serum cholesterol.

The effects of zero-erucic acid rapeseed oil and rapeseed oil-containing margarine on plasma fatty acid composition and serum cholesterol were studied in butter users (n 43). Compliance to the substitution was followed by fatty acid analysis of total plasma and plasma phospholipids. The amount of substitute fats represented, on average, 21% of total fat and 8% of total energy intake. Changes in the relative fatty acid composition of plasma phospholipids indicated further fatty acid metabolism, and were closely related to the serum cholesterol level. The reduction in saturated fatty acids led to a significant increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFA) with the rapeseed oil diet, whereas the margarine caused a significant rise in n-6 PUFA only. The increase in the proportions of the two PUFA families occurred in accordance with their competitive order, most completely with the rapeseed oil diet. When butter was replaced by rapeseed oil, low-density-lipoprotein-cholesterol decreased by an average of 9.1% without a reduction in high-density-lipoprotein-cholesterol. During margarine substitution the reduction was 5.2%, on average. Of the plasma phospholipids, alpha-linolenic acid and the linoleic:stearic acid ratio, but not oleic acid, were the components most significantly correlated with serum cholesterol levels or the decrease in these levels. The results show that rapeseed oil can act primarily as a source of essential fatty acids, rather than that of monoenes, in the diet of butter users.

Polyunsaturated fatty acids in plasma, red blood cells and mononuclear cell phospholipids of patients with atopic dermatitis.

Recent studies of polyunsaturated fatty acids (PUFA) in plasma and blood cell components of patients with atopic diseases have indicated disordered fat metabolism as linoleic acid (18:2n-6) tends to be increased while the more unsaturated fatty acids, such as gamma-linolenic acid (18:3n-6) and arachidonic acid (20:4n-6) are present in decreased amounts. To further clarify these abnormalities, we examined the PUFA content in phospholipids derived from plasma, red blood cells and mononuclear cells (MNC) in patients with atopic dermatitis. In plasma no significant differences were found between patients and controls. In red blood cells dihomo-gamma-linolenic acid (20:3n-6) was reduced in eczema patients, as compared with controls. The most significant findings in eczema patient MNC were reduced ratios of 20:4n-6/20:3n-6 in total lipids and in phosphatidyl ethanolamine (PE) and of 20:4n-6/18:2n-6 in both total lipids, phosphatidyl choline (PC) and PE. These findings indicate a disordered fatty acid metabolism in MNC of patients with atopic dermatitis. It is possible that these changes in the fatty acid profile of MNC may account for some of the immunological abnormalities seen in these patients.

Transport of n-3 fatty acids from the intestine to the retina in rats.

This study was undertaken to determine the mode of transport of the essential (n-3) fatty acids docosahexaenoic acid 22:6(n-3) and linolenic acid 18:3(n-3). Male weanling Sprague-Dawley rats received a mixture of corn oil and [14C]18:3(n-3) or [14C]22:6(n-3) by gavage. At periods of 1 to 4 days after the injection, four rats per time point were killed and samples of blood were taken via heart puncture and the livers and retinas were collected. Blood lipoproteins and plasma proteins were separated by ultracentrifugation and analyzed by HPLC. Lipids were extracted and saponified and the fatty acids were converted to phenacyl esters for separation of individual fatty acids. After 1 and 2 h, radioactivity from 18:3(n-3) and 22:6(n-3) was observed primarily in the chylomicron/very low density lipoprotein fraction. By 4 h, radioactivity in the lipoprotein fraction was greatly decreased, with a small amount of radioactivity associated with albumin in the soluble protein fraction. After 24 h, the total amount of radioactivity associated with lipoprotein was further reduced, with more than half of the remaining label occurring in association with albumin and another unidentified protein. In the liver, 22:6(n-3) was concentrated in triacylglycerols (40.7%) and phospholipids (51.1%), with a maximum specific activity at 4 h. In the rod outer segments (ROS), the specific activity of [14C]22:6(n-3) increased to a maximum at 24 h and maintained a high level even at 4 days. These data suggest that after injection, 18:3(n-3) and 22:6(n-3) are esterified to triglyceride and phospholipid by the intestinal absorptive cells and transported in chylomicrons to the liver. After conversion of 18:3(n-3) to 22:6(n-3) in the liver, the retina accumulates 22:6(n-3) which may be transported from the liver via albumin and another unidentified protein, and is retained by the rod outer segments.

Antihypertensive effect of gamma-linolenic acid in spontaneously hypertensive rats.

The effects of chronic treatments of adult (aged 16-17 weeks) spontaneously hypertensive rats (SHRs) with different doses of gamma-linolenic acid (GLA) on blood pressure, heart rate, and body weight were studied. Twice-daily injection of SHRs with GLA lowered systolic blood pressure from 175 +/- 4 to 145 +/- 4 mm Hg within 1 week; systolic blood pressure in all three treated groups became stabilized in the normotensive range after 2 weeks of treatment. Control SHRs injected with olive oil showed only a transient decrease in systolic blood pressure on the third day. Heart rate and body weight were not affected by GLA treatment. Withdrawal of GLA treatment resulted in a rapid rise in systolic blood pressure within 1 day from 140 +/- 3 to 165 +/- 3 mm Hg, and it stabilized after 1 week at 191 +/- 5 mm Hg in the three experimental groups. A rapid increase in systolic blood pressure from 175 +/- 5 to 203 +/- 5 mm Hg was also observed in the control group treated with olive oil 1 day after the withdrawal of the treatment. Addition of aspirin (3 mg/kg) with the GLA treatment in olive oil abolished the antihypertensive effect of GLA. In contrast, once-daily treatment with GLA also lowered systolic blood pressure of the SHR, but blood pressure was still in the hypertensive range (170 +/- 6 mm Hg). Systolic blood pressure of control SHRs treated with olive oil was not affected. Plasma from untreated SHRs contained a small amount of GLA. One hour after the injection, the plasma level of GLA increased. We conclude that GLA when given twice daily is an effective antihypertensive agent in the SHR.

Effects of diets high in saturated fatty acids, canola oil, or safflower oil on platelet function, thromboxane B2 formation, and fatty acid composition of platelet phospholipids.

Platelet function and fatty acid composition were investigated in 30 healthy male subjects who ate a controlled-saturated-fatty-acid (baseline) diet for 3 wk and then consumed either safflower oil or canola oil as a major fat source for 8 wk. Fatty acid composition of platelet phospholipids reflected changes in dietary fatty acid composition. Compared with baseline a 35% decrease (P less than 0.05) in arachidonic acid was observed in platelet phospholipids of the canola-oil diet group while long chain n-3 fatty acids rose 7-26% (P greater than 0.05). Compared with baseline both unsaturated-fatty-acid diets reduced platelet aggregation at 3 wk of oil-based diet feeding (P less than 0.01) whereas only canola oil influenced platelet function (lowered ATP secretion) at 8 wk (P less than 0.01). No significant difference was observed in thromboxane B2 concentrations between oil-treatment groups at 8 wk. Both oil-based diets had short-term beneficial effects on platelet function but the effect of canola oil persisted longer.

[Effects of dietary omega-6 and omega-3 fatty acids on levels of long chain polyunsaturated fatty acids in erythrocytes]. / Effets des acides gras omega 6 et omega 3 alimentaires sur les concentrations en acides gras polyinsaturés à longue chane des érythrocytes.

C18:2 omega 6/C18:3 omega 3 ratio was lowered in the diet of Elderly subjects. This was done by the replacement of usual sunflower oil by rapeseed oil or by supplementing soybean oil. This diet modification induced an increase of EPA (C20:5 omega 3) and DHA (C22:6 omega 3) in red cell phospholipids. The omega 6 fatty acids (C18:2 and C20:4) were slightly modified. Therefore, dietary C18:2 omega 6/C18:3 omega 3 ratio, seems to play an important role in the determination of membrane highly unsaturated fatty acid levels.

Visual function in patients undergoing long-term total parenteral nutrition.

To evaluate the effects of long-term total parenteral nutrition (TPN) on eye function, 27 adults and 12 children in the UCLA Home TPN Clinic underwent ophthalmoscopic examination and visual-function testing. Direct inspection of the fundus showed a marked granularity of the retinal pigmented epithelium in some patients. About one-half of the children and one-third of the adults tested had at least one and usually two abnormalities in their electroretinogram. Determination of blood nutrients thought to affect vision revealed that zinc and vitamin E were within normal range. Vitamin A concentrations were above normal in 10 of 19 adults and selenium concentrations were below normal in 10 of 10 children and 17 of 21 adults tested. Linoleic and linolenic acid concentrations were low; plasma, platelet, and urine taurine concentrations were significantly lower than normal. Despite these diffuse nutrient abnormalities, only zinc and vitamin E concentrations correlated significantly with any index of visual function.