[Pain therapy in the elderly:7-day transdermal buprenorphine patch in clinical practice. Results of a non-interventional study]. / Schmerztherapie im Alter: Buprenorphin-7-Tage-Pflaster in der Praxis - Ergebnisse einer nicht-interventionellen Studie.

BACKGROUND: Chronic pain in the elderly is common. Especially in the elderly inadequate treatment of pain can cause significant functional impairmentand deterioration of qualityof life. METHODS: Theaim of this post-marketing surveillance study was to collect data from clinical practice on the analgesic efficacy and safety of the 7-day transdermal buprenorphine patch in patients with chronic non-malignant pain pre-treated with opioids. A total of 2713 elderly multimorbid patients were switched to 7-day transdermal buprenorphine patch from previous opioid treatment mainly due to inadequate analgesia. 83% of patients received a 7-day transdermal buprenorphine patch dosage > or = 10 microg/h. During the 8-weekobservation period, data on pain intensity, quality of sleep/life (NRS-11 point scales) and safety wererecorded. RESULTS: Mean pain intensity decreased by 4 points with 7-day transdermal buprenorphine patch (p < or = 0.001). Quality of sleep and life as well as social activities and self-reliance improved significantly. Compliance and tolerability were assessed as very good/good in > 90% of patients. Adverse drug reactions (ADRs) occurred in 3% of patients and corresponded to 90.1% to the already-known spectrum of ADRs of 7-daytransdermal buprenorphinepatch. CONCLUSIONS: The results confirm that elderly patients with opioid pre-treatment benefit from a switch to 7-day transdermal buprenorphine patch with regard to reduction of pain and improved quality of life.

Importance and value of adjuvanted influenza vaccine in the care of older adults from a European perspective - A systematic review of recently published literature on real-world data.

BACKGROUND: There is an urgent need for improved influenza vaccines especially for older adults due to the presence of immunosenescence. It is therefore highly relevant to compare enhanced influenza vaccines with traditional influenza vaccines with respect to their effectiveness. OBJECTIVE: To compare vaccine efficacy and effectiveness of adjuvanted influenza vaccines (aTIV/aQIV) vs. non-adjuvanted standard-dose (TIV/QIV) and high-dose (TIV-HD/QIV-HD) influenza vaccines regarding influenza-related outcomes in older adults, complementing findings from the European Centre for Disease Prevention and Control (ECDC)'s systematic review of enhanced seasonal influenza vaccines from February 2020. METHODS: A systematic literature search was conducted in Embase and MEDLINE to identify randomised controlled trials, observational studies and systematic reviews, published since ECDC's systematic review (between 7 February 2020 and 6 September 2021). Included studies were appraised with either the Cochrane Risk of Bias tool, ROBINS-I or AMSTAR 2. RESULTS: Eleven analyses from nine real-world evidence (RWE) studies comprising ∼53 million participants and assessing the relative vaccine effectiveness (rVE) of aTIV vs. TIV, QIV and/or TIV-HD in adults aged ≥65 years over the 2006/07-2008/09 and 2011/12-2019/20 influenza seasons were identified. Nine analyses found that aTIV was significantly more effective than TIV and QIV in reducing influenza-related outcomes by clinical setting and suspected influenza outbreaks (rVE ranging from 7.5% to 25.6% for aTIV vs. TIV and 7.1% to 36.3% for aTIV vs. QIV). Seven analyses found similar effectiveness of aTIV vs. TIV-HD in reducing influenza-related medical encounters, inpatient stays and hospitalisations/emergency room visits. In three analyses, aTIV was significantly more effective than TIV-HD in reducing influenza-related medical encounters and office visits (rVE ranging from 6.6% to 16.6%). Risk of bias of identified studies was moderate to high. CONCLUSIONS: Our study suggests that both adjuvanted and high-dose vaccines are effective alternatives for vaccination programmes in older adults and preferable over conventional standard-dose vaccines.

Regulation of adhesion molecule expression in human endothelial and smooth muscle cells by omega-3 fatty acids and conjugated linoleic acids: involvement of the transcription factor NF-kappaB?

We previously showed conjugated linoleic acids (CLA) inhibited TNF-alpha-induced monocyte (THP-1) adhesion to human umbilical vein endothelial cells (HUVEC) in vitro which involved an increase in platelet activating factor (PAF). Here we show adhesion molecule (ADM) regulation by fatty acids and the differing role of nuclear factor kappa B (NF-kappaB) activation in HUVEC and vascular smooth muscle cells (vSMC). CLA and omega-3 long-chain polyunsaturated fatty acids (PUFA) (FA) reduced TNF-alpha-induced expression of ADMs (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin) on HUVEC and vSMC to different extents depending on FA type and concentration, cell type and method of analysis. IkappaBalpha phosphorylation in HUVEC and vSMC and transient transfection with NF-kappaB-luciferase reporter plasmid (HUVEC only) indicated differential NF-kappaB involvement during FA modulation (cis-9, trans-11; trans-10, cis-12 and a 50:50 mix of both CLA isomers; eicosapentaenoic acid (EPA); docosahexaenoic acid (DHA)). TNF-alpha-induced ADM expression in both cell types by 2-10-fold. In HUVEC, CLA t10, c12 and CLA mix (50:50 mixture of CLA c9, t11 and t10, c12) and EPA and DHA reduced ICAM-1 expression (15-35%) at 12.5, 25 and/or 50 microM. VCAM-1 expression was reduced by 25 microM t10, c12 isomer and mix; omega-3 PUFA and other concentrations of CLA and TNF-alpha-induced E-selectin expression were unaffected. TNFalpha-induced inhibitor kappa B (IkappaB) phosphorylation was biphasic peaking at 5 min in both cell types and 60 and 120 min in HUVEC and SMC, respectively. IkappaBalpha phosphorylation and NF-kappaB activity was reduced (29% and 30%, respectively) by 25 microM CLA mix. n-3 PUFA did not reduce IkappaBalpha phosphorylation or NF-kappaB activity but reduced ADM expression. We show that n-3 PUFA and CLA reduce expression of ADM on HUVEC and vSMC. This reflected reduced adherence of monocytes to HUVEC previously reported by our group. Reduction of ICAM-1 and VCAM-1 protein expression by n-3 PUFA was less dependent on the NF-kappaB pathway than reduction by CLA which reflected the parallel attenuation of NF-kappaB activity. This indicated involvement of other transcription factors (i.e. AP-1) in the FA regulation of ADM expression and has, to our knowledge, not been previously reported.

Biomarkers of oxidative stress in schizophrenic and control subjects.

Increasing evidence indicates that oxidative injury exists in schizophrenia. Although it may not be the main cause, oxidative damage has been suggested to contribute to the pathophysiology and may account for deteriorating course and poor outcome in schizophrenia. A human study was undertaken, therefore, to investigate possible differences in biomarkers of DNA, lipid and protein oxidation in schizophrenic (n=16) and control subjects (n=17). Plasma vitamin C levels were also compared in both groups. Cellular DNA damage and plasma protein carbonyl levels were increased in the schizophrenic group compared to control subjects but not significantly. However, DNA damage in lymphocytes from the male schizophrenic group was significantly higher than the female group. Biomarkers of lipid peroxidation and plasma vitamin C levels also revealed no significant difference between the two groups under investigation, although a significant elevation in plasma vitamin C was observed in the female control group when compared to the male groups.

Effects of isomeric cis and trans eighteen carbon monounsaturated fatty acids on porcine platelet function.

The effects of different positional cis and trans isomers (9, 11, 12 and 13) of C(18) monoenoic fatty acids on the response of porcine platelets to collagen and thrombin stimulation were determined. Cis isomers inhibited aggregation in response to 2 microgram/ml or 5 microgram/ml collagen and 0.1 U/ml of thrombin with almost equal effectiveness, with the exception of the 9- and 11-isomers which gave reduced inhibition of aggregation with thrombin and collagen stimulation respectively. All cis isomers inhibited TXA(2) formation (determined as TXB(2)) elicited by collagen with almost equal effectiveness. Trans isomers were less effective than cis in inhibiting collagen induced aggregation particularly at the higher collagen concentrations. Inhibition of TXB(2) formation was less marked with trans isomers but a clear dissociation between the extent of inhibition of aggregation and TXB(2) formation was evident. Cis isomers also inhibited aggregation in response to 0.1 U/ml thrombin whereas trans isomers augmented aggregation but still reduced TXB(2) formation. Isomers did not elicit their effects through incorporation into platelet membrane phospholipids. Aggregation studies were carried out using the impedance method which is more sensitive than the optical method hitherto described, particularly for lipid studies.

Temperature, pressure and cholesterol effects on bilayer fluidity; a comparison of pyrene excimer/monomer ratios with the steady-state fluorescence polarization of diphenylhexatriene in liposomes and microsomes.

Pyrene excimer/monomer (E/M) ratios have been compared with the steady-state fluorescence polarization (P) of diphenylhexatriene (DPH) in multilamellar liposomes of dilaurylphosphatidylcholine and rat liver microsomes. The purpose was to use the well-understood properties of DPH to reveal the nature of bilayer fluidity which pyrene manifests as an E/M ratio. Reducing the temperature (from 37 degrees C to 8 degrees C), increasing the hydrostatic pressure (from 0.1 to 70 MPa), and, in liposomes, cholesterol enrichment (up to 0.30 mole fraction) separately decreased the E/M ratios and increased P. The pyrene membrane/buffer partition coefficient was affected by temperature but not by pressure, and in the case of cholesterol enrichment, it was assumed to be unaffected. Plots of P as a function of the E/M ratio showed the two to be closely correlated (r = 0.99 in liposomes and 0.96 in microsomes), independent of the treatment used to reduce fluidity. The apparent activation volume and enthalpy for excimer formation was calculated and compared with published data. Pyrene E/M ratios probably reflect the intermolecular volume (fluidity) of the outer region of the bilayer, which is reduced by a decrease in temperature and an increase in pressure and cholesterol. DPH reports the bilayer interior, which is similarly ordered by the experimental treatments. The regional distinction between the two probes, however, accounts for the divergence of E/M ratios and P, which has been reported in membranes enriched with fluidizing fatty acids.

Modulation of glutathione peroxidase activity in human vascular endothelial cells by fatty acids and the cytokine interleukin-1 beta.

Objectives of this study were (a) to assess the extent of oxidative stress elicited in human endothelial cells by n-3, n-6 and n-9 mono- and polyunsaturated fatty acids and by interleukin-1 beta and (b) to determine how such stress influenced glutathione peroxidase (GSHPx) activity. Fatty acids were co-incubated with human vascular endothelial cells (HUVEC) for 24 h. Lipid peroxidation, monitored as conjugated diene (CD) formation, increased 3-4-fold with increasing eicosapentaenoic and docosahexaenoic acids: 2-3-fold with linoleic acid; decreased by 50% with arachidonic acid and was unchanged with oleic acid. Changes in glutathione peroxidase activity mirrored conjugated diene formation in the HUVEC incubated with fatty acids. Interleukin-1 beta also increased glutathione peroxidase and conjugated diene formation; the latter increased enzyme activity dose-dependently suggesting a possible role for this oxidation product in the induction of glutathione peroxidase activity. The ability of fish oil fatty acids to induce antioxidant enzymes, particularly those of the glutathione redox system, may be an important mechanism protecting cells and tissues against oxidative and inflammatory cytokine elicited damage.

Effect of CLA supplementation on immune function in young healthy volunteers.

OBJECTIVES: This study investigated the effect of dietary CLA supplementation (3g/day; 50:50 mix of the two major isomers) on the immune system and plasma lipids and glucose of healthy human (male and female) volunteers. DESIGN: Double-blind, randomized, reference-controlled study. SUBJECT AND INTERVENTION: A total of 28 healthy male and female participants aged 25-50 y received either high oleic sunflower oil (reference) or 50% CLA 9-11 and 50% CLA 10-12 CLA isomers (50:50 CLA-triglyceride form). The treatments were given as supplements in soft-gel capsules providing a total 3 g (6 x 500 mg capsules) per day in treatment groups for 12 weeks. A 12-week washout period followed the intervention period. RESULTS: Levels of plasma IgA and IgM were increased (P < 0.05 and 0.01 respectively), while plasma IgE levels were decreased (P < 0.05). CLA supplementation also decreased the levels of the proinflammatory cytokines, TNF-alpha and IL-1beta (P < 0.05), but increased the levels of the anti-inflammatory cytokine, IL-10 (P < 0.05). Another aspect of immune function, delayed type hypersensitivity (DTH) response, was decreased during and after CLA supplementation (P < 0.05). However, plasma glucose, lipids, lymphocyte phenotypic results were not affected significantly by CLA. CONCLUSION: This is the first study to show that CLA, a fatty acid naturally found in dairy and meat products, can beneficially affect immune function in healthy human volunteers. SPONSORSHIP: This study was supported by Loders-Croklaan, The Netherlands and SEERAD (Scottish Executive Environmental Rural and Agriculture Department).

Nutrition and the surgical patient: triumphs and challenges.

The understanding of the role of nutrition in the surgical patient has lead to major developments in the nutritional support of patients undergoing surgery. Reductions in morbidity by ensuring that patients receive optimal nutritional support can be achieved. Furthermore, the use of nutrients to modify immune, inflammatory and metabolic processes also offers new possibilities for reducing morbidity following major surgery. However, we are only at an embryonic stage in our understanding of how nutrients and nutrition affect the genome and this knowledge offers exciting possibilities in the future for modulating many key intracellular processes, particularly in the patient with cancer.

Altered platelet stearic to oleic acid ratio in malignancy.

Alteration of lipid metabolism associated with malignant disease is well-documented and some studies have suggested a reduced stearic to oleic acid ratio occurs in erythrocytes in cancer patients. In this study, the fatty acid composition was measured in platelets, which are capable of lipid synthesis and have a much shorter lifespan. While demonstrating any malignancy related change in the platelet stearic to oleic acid ratio the study aimed to assess whether it could be of value as a tumour marker. Patients with active malignancy (n = 46) had a lower ratio of stearic to oleic acid than those with malignant disease in clinical remission [mean (S.D.) 1.08 (0.22) vs. 1.26 (0.30), P less than 0.01], and 22 healthy controls [1.29 (0.24), P less than 0.001]. However in a group of 17 patients with chronic, non-malignant diseases the ratio was also lower than in normal controls and similar to that seen in the active malignancy group [0.97 (0.29)]. Thus while a reduction in platelet stearic to oleic acid ratio was found in active malignancy, it is not specific to neoplastic disease.

Red cell membrane fatty acids, cytosolic phospholipase-A2 and schizophrenia.

Forty subjects with schizophrenia and 40 age- and sex-matched controls were recruited, and blood samples were obtained for analysis of red cell membrane fatty acid composition by capillary gas chromatography. A blood sample was also taken from the same population to test for allelic association between schizophrenia and a polymorphism close to the promoter site of the cytosolic phospholipase-A2 gene which is mapped to chromosome 1q25. The schizophrenic population was heterogeneous with regards age, symptoms severity and treatment. A significantly higher percentage concentration of dihomogamma-linolenic acid (DGLA) was found in the red cell membranes of schizophrenics compared to matched controls. All other fatty acids examined showed no difference from the normal population. No correlation was found between any demographic factor, treatment variable, diet, drug use, alcohol or tobacco consumption which could explain the biochemical findings. A negative correlation was found between the concentration of DGLA in red blood cell (RBC) membranes and severity of symptoms of schizophrenia. In particular, there was a significant correlation (r = -0.41, p = 0.009) between DGLA percentage concentrations and 'disorganised' symptoms. No association was found between schizophrenia and alleles of the polymorphism near the phospholipase-A2 gene or between fatty acid concentrations and the presence of any particular alleles. This study therefore finds support for membrane phospholipid abnormalities in patients with schizophrenia and particular symptom clusters, but does not replicate a previous report of an allelic association between a polymorphism close to the site of the cytosolic phospholipase-A2 gene and schizophrenia.

Cell signal mechanisms, conjugated linoleic acids (CLAs) and anti-tumorigenesis.

Fats have been adversely implicated in the aetiology of many forms of cancer yet evidence is accumulating that certain types of fatty acids have anticancer properties. This is well documented for fish-oil fatty acids of the n-3 family. Recently, fatty acids found to occur naturally in ruminant-derived food products were found to have anticancer properties. These fatty acids were identified as conjugated linoleic acids (CLAs) derived from the parent linoleic acid by its partial hydrogenation by rumen bacteria. Studies with tumour-bearing animals have shown that consumption of CLAs particularly with regard to breast and prostate cancer is beneficial. Studies with cancer cells have also shown that these fatty acids can inhibit cell proliferation and induce cell death. However, little is known regarding the mechanisms of action of these CLAs. In particular, which cellular signal mechanisms are regulated by CLAs which can explain their anticancer properties. We have shown that CLAs specifically up-regulate cell signal systems at the level of gene expression (mRNA, protein) in human breast and prostate cancer cells which are responsible for the induction of apoptosis or programmed cell death. These findings support the anticancer effects of CLA found in animal models and indicate similar effects could occur in man.

Effect of fish-oil and vitamin E supplementation on lipid peroxidation and whole-blood aggregation in man.

Free-living, healthy young men aged 21-35 years were divided into two groups, each group received dietary supplements of 15 g/day of fish-oil in the form of MaxEPA capsules, with or without an extra 400 I.U. of vitamin E, for two periods of four weeks. Blood samples were taken from an antecubital vein at two-week intervals. Plasma thiobarbituric acid reactive substances, conjugated dienes, vitamin E, creatine kinase, glucose and serum cholesterol were determined. Whole blood aggregation in response to collagen was determined by an electrical impedance method. Fish oil supplementation increased plasma thiobarbituric acid reactive substances after two weeks in vitamin E supplemented and non-supplemented groups but values returned to normal after four weeks in both groups regardless of the type of supplement given. No comparable increase in plasma conjugated dienes, creatine kinase or serum cholesterol was observed, the latter did not change significantly with diet. Plasma glucose increased when fish oil was supplemented, but only in the absence and not in the presence, of vitamin E supplementation. Whole blood aggregation decreased with the dietary fish oil in the presence, but increased in the absence, of vitamin E supplementation. These findings indicate an increased requirement for dietary antioxidant with high intakes of fish oil concentrates in man.

Concentrations of linoleic acid in adipose tissue differ with age in women but not men.

Samples of adipose tissue, taken post-mortem from the anterior abdominal wall near the umbilicus, were obtained from road-accident victims in the Aberdeen area; subjects were of either sex with a wide age distribution (7-88 years). Similar samples were obtained from elderly females (mean age 77) who had died in Aberdeen Royal Infirmary from a variety of causes. Fatty acid compositions of samples were determined by capillary gas chromatography of methyl esters, which were obtained by direct esterification of the adipose tissue. The mean linoleic acid content for all samples was low compared with published values for similar samples from Europe and North America. Cumulative frequency distribution curves for linoleic acid did not differ with age in males but significant differences (P less than 0.001) occurred in females, with decreased concentrations in those aged over 60 compared to younger groups. Concentrations of trans-unsaturated fatty acids ranged between 2 and 7 per cent but did not differ significantly between groups. Low adipose concentrations of linoleic acid are regarded as a reflection of its reduced long-term dietary intake and as a risk factor for the development of coronary heart disease.

The Mediterranean diet: protective or simply non-toxic?

There is clear evidence that populations living in Mediterranean countries enjoy a longer life expectancy than Northern Europeans. Genetic or racial factors do not explain these societal differences as revealed by migrant studies. The major causes of death in affluent societies, cardiovascular disease, cancers and digestive disorders, show markedly different incidence rates in different European countries. These differences seem to depend on the varied dietary patterns in Europe but the classic lipid hypothesis alone fails to explain the differing rates of coronary heart disease. Limiting the free radical damage to cholesterol thereby reducing the induction of atherosclerosis is a plausible explanation for the finding that some countries, e.g. France as well as Mediterranean countries with their high fruit and vegetable consumption, are well protected against coronary heart disease. The Mediterranean diet is low in saturated fat content but contains either a high or low content of starch and total fat. A high fat diet reveals the genetically determined individual propensity to obesity, e.g. in Greece, but does not predispose to cardiovascular disease or mitigate against the cancer protective properties derived from the vegetable component of the Greek diet. Studies in the Mediterranean area highlight the considerable dietary diversity which is possible for achieving longevity.

Dietary intakes of polyunsaturated fatty acids and indices of oxidative stress in human volunteers.

OBJECTIVE: To assess whether nutritionally-relevant changes in polyunsaturated fatty acid (PUFA) intake alter indices of oxidative stress in human volunteers DESIGN: A split plot/change over dietary study where half the volunteers consumed a diet containing 5% PUFA (low PUFA) as food energy for 4 weeks and after a 6 week washout period consumed a 15% PUFA (high PUFA) diet for another 4 weeks. The second group of volunteers completed this protocol in reverse. Total fat, carbohydrate, protein and vitamin E contents of the diets were constant. SUBJECTS: 10 healthy, non-smoking, male volunteers aged 32.6 +/- 1.7 y RESULTS: There was a significant increase in whole blood oxidised glutathione (P < 0.05), an index of oxidative stress, after consumption of the high PUFA diet. Moreover, urinary thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, significantly increased (P = 0.038) following consumption of the high PUFA diet and decreased (P = 0.031) after consuming the low PUFA diet. However, there was no change in non specific plasma indices of lipid peroxidation, conjugated dienes and TBARS, nor in red cell antioxidant enzymes glutathione peroxidase, glutathione reductase, and catalase. However, superoxide dismutase significantly decreased (13%, P=0.018) after consumption of the low PUFA diet. Total cholesterol increased by 13% (P=0.014) after consumption of the low PUFA diet. CONCLUSIONS: This study indicates that although increasing dietary levels of PUFA may favourably alter cholesterol profiles, the same dietary changes may adversely affect some indices of lipid peroxidation. Care should be taken when providing dietary advice on PUFA intake and an adequate intake of antioxidants to match any increased PUFA may be important for preventing oxidative stress.

Decreased phospholipid polyunsaturated fatty acid content and superoxide dismutase activity in cardiac muscle of malignant hyperthermia-susceptible swine.

Homogenates of cardiac left ventricle from malignant hyperthermia-susceptible (MHS) pigs produced a circa 72% more pentane than those from malignant hyperthermia-resistant (MHR) animals, indicating enhanced peroxidation of n-6 fatty acids. This is consistent with the observed circa 70% decrease in total phospholipid polyunsaturated fatty acids (PUFA) in MHS compared with MHR tissue, a decrease mainly due to the quantitatively greater loss of n-6 PUFA. Although the percentage loss of n-3 PUFA was greater than that of n-6 PUFA (90% vs 60%), absolute amounts were insufficient to register as ethane production. Three-fold greater phospholipid content of MHS compared with MHR ventricles indicates reduced neutral lipid content probably due to increased catecholamine stimulation. These findings were associated with a small but significant decrease in superoxide dismutase activity in MHS tissues.

The participation of soluble factors in the omega-oxidation of fatty acids in the liver of the sheep.

The removal of soluble components from an ovine hepatic microsomal preparation decreased the omega-hydroxylation of dodecanoic and hexadecanoic acids. The results suggest that one or more soluble components play a role in the microsomal omega-hydroxylation of fatty acids. The possible roles in the reaction of catalase (known to stimulate the microsomal desaturations of fatty acids and alkylglycerols) and superoxide dismutase were investigated. The addition of these enzymes to the complete (but not the washed) microsomal preparation stimulated both the initial omega-hydroxylation reaction and the subsequent dehydrogenation reactions of the omega-oxidation pathway. The similarity of the effects of catalase and superoxide dismutase and stimulation of two different steps of the omega-oxidation pathway suggest that these agents are acting indirectly by removing active oxygen species rather than directly on the enzymes of microsomal fatty acid omega-hydroxylation.

Effect of a diet rich in sunflower oil on aspects of lipid metabolism in the genetically-obese rat.

Aspects of the lipid metabolism of male, obese and lean Zucker rats were compared using animals which had been fed ad libitum for 32 days on a diet (HS) which contained 200 g sunflowerseed oil/kg or one (LS) which contained 50 g/kg of the oil. When compared with the LS diet, the HS diet decreased the characteristic lipid accretion in the liver of obses rats from 126 mg (LS) to 81 mg (HS)/g wet weight; corresponding values for the lean rats were 39 mg and 56 mg/g wet weight of liver, respectively. The HS diet depressed lipid synthesis de novo by liver homogenates and decreased the delta9-desaturase activity of liver microsomes from obese and lean rats by about 50%. delta9-Desaturase activity in vitro was also depressed by the addition of linoleic acid to liver microsomes from both obese and lean rats fed ad libitum on a standard laboratory diet. Depressed delta9-desaturase activity, due to ingestion of the HS diet, was reflected in lower ratios of 16:1/16:0 and 18:1/18:0 fatty acids in tissue lipids from obese and lean rats. Ingestion of the HS compared with the LS diet resulted in increased proportions of 18:2omega6 in liver lipids and adipose tissue triacylglycerols of obese and lean rats. The HS diet also increased the proportions of 20:4omega6 in adipose triacylglycerols of obese and lean rats and in liver lipids of obese animals but not in their lean littermates.