Fatty acids in formulae for term infants: compliance of present recommendations with the actual human milk fatty acid composition of geographically different populations.

AIM: Recommendations for formula fatty acids (FA) are largely based on the mature human milk FA composition. This study aimed to investigate whether current recommendations for formula FA for term infants comply with the actual breast-milk FA composition of geographically distinct populations and to provide more realistic grounds for future recommendations. METHODS: 455 mature breast-milk samples were collected in different countries over 25 y. Recommendations of different organizations were projected on their FA data. FA interrelationships were calculated with Spearman's rank tests. FA compositions of 30 formulae were compared with those of breast milk. RESULTS: Many samples from non-Western communities did not meet the recommendations for formula 12:0, 14:0 and 18:2omega6, since these are mainly based on breast milk of mothers living in Western countries. Recommendations for 18:3omega3, 18:2omega6/18:3omega3, 20:4omega6 and 22:6omega3 were not met by many milk samples, which may point to the poorly developed recommendations for long-chain polyunsaturated FA. Most of the investigated breast-milk FA (12:0, 14:0, 16:0, 18:0, 18:3omega3, 22:6omega3, 18:2omega6, 20:4omega6, 18:1omega9) were either positively or negatively interrelated. Many formulae had FA compositions that were not consistent with the physiological interrelationships of FA in breast milk. CONCLUSION: Future recommendations, if based on human milk, should derive from its FA balance, as indicated by the FA interrelationships. A "humanized" formula FA composition would in this sense be any composition that cannot be distinguished from that of breast milk by techniques such as principal component analysis.

Assessment of essential fatty acid and omega3-fatty acid status by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3.

BACKGROUND: Early suspicion of essential fatty acid deficiency (EFAD) or omega3-deficiency may rather focus on polyunsaturated fatty acid (PUFA) or long-chain PUFA (LCP) analyses than clinical symptoms. We determined cut-off values for biochemical EFAD, omega3-and omega3/22:6omega3 [docosahexaenoic acid (DHA)]-deficiency by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3, respectively. METHODS: Cut-off values, based on 97.5 percentiles, derived from an apparently healthy omnivorous group (six Dominica breast-fed newborns, 32 breast-fed and 27 formula+LCP-fed Dutch low-birth-weight infants, 31 Jerusalem infants, 33 Dutch 3.5-year-old infants, 69 omnivorous Dutch adults and seven Dominica mothers) and an apparently healthy group with low dietary LCP intake (81 formula-fed Dutch low-birth-weight infants, 12 Dutch vegans). Cut-off values were evaluated by their application in an EFAD suspected group of 108, mostly malnourished, Pakistani children, three pediatric patients with chronic fat-malabsorption (abetal-ipoproteinemia, congenital jejunal and biliary atresia) and one patient with a peroxisomal beta-oxidation disorder. RESULTS: Erythrocyte 20:3omega9, 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3 proved age-dependent up to 0.2 years. Cut-off values for ages above 0.2 years were: 0.46mol% 20:3omega9 for EFAD, 0.068mol/mol 22:5omega6/20:4omega6 for omega3-deficiency, 0.22mol/mol 22:5omega6/22:6omega3 for omega3/DHA-marginality and 0.48mol/mol 22:5omega6/22:6omega3 for omega3/DHA-deficiency. Use of RBC 20:3omega9 and 22:5omega6/20:4omega6 cut-off values identified 20.4% of the Pakistani subjects as EFAD+omega3-deficient, 12.9% as EFAD+omega3-sufficient, 38.9% as EFA-sufficient+omega3-deficient and 27.8% as EFA-sufficient+omega3-sufficient. The patient with the peroxisomal disorder was classified as EFA-sufficient, omega3-sufficient (based on RBC 22:5omega6/20:4omega6) and omega3/DHA-deficient (based on RBC 22:5omega6/22:6omega3). The three other pediatric patients were classified as EFAD, omega3-deficient and omega3/DHA-deficient. CONCLUSION: Use of the combination of the present cut-off values for EFA, omega3 and omega3/DHA status assessment, as based on 97.5 percentiles, may serve for PUFA supplement intervention until better concepts have emerged.

Estimated biological variation of the mature human milk fatty acid composition.

We estimated the biological variation (CV(biol)) of 28 fatty acids (FA) in 465 mature human milk samples from The Netherlands, Caribbean, Jerusalem, Tanzania and Pakistan, by using data from the observed variation (CV(obs)) and analytical variation (CV(anal)). CV(biol) of the various regions was remarkably similar. The average CV(biol) of 455 samples, Pakistan excluded, ranged from 12.7% for 16:0 and 18.9% for 18:1 omega 9 to 68% for 22:6 omega 3 and about 100% for 20:5 omega 3. Those of 20:4 omega 6, 18:2 omega 6 and 18:3 omega 3 were 28.0, 33.0 and 37.3%, respectively. Because of the large CV(biol) and the many dietary changes in recent history, it seems impossible to consider the present human milk FA composition as the 'gold standard' for infant formula. Optimal human milk FA composition should rather derive from populations that consume traditional diets or from the scientific data that show the function of the individual FAs in neonatal development.

Short-term supplementation of low-dose gamma-linolenic acid (GLA), alpha-linolenic acid (ALA), or GLA plus ALA does not augment LCP omega 3 status of Dutch vegans to an appreciable extent.

Vegans do not consume meat and fish and have therefore low intakes of long chain polyunsaturated fatty acids (LCP). They may consequently have little negative feedback inhibition from dietary LCP on conversion of alpha -linolenic acid (ALA) to the LCP omega 3 eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. We investigated whether supplementation of nine apparently healthy vegans with 2.01 g ALA (4 ml linseed oil), 1.17 g gamma-linolenic acid (GLA) (6 ml borage oil) or their combination increases the LCP omega 3 contents of erythrocytes (RBC) and platelets (PLT), and of plasma phospholipids (PL), cholesterol esters (CE) and triglycerides (TG). The supplements changed the dietary LA/ALA ratio (in g/g) from about 13.7 (baseline) to 6.8 (linseed oil), 14.3 (borage oil) and 6.4 (linseed + borage oil), respectively. ALA or GLA given as single supplements did not increase LCP omega 3 status, but their combination augmented LCP omega 3 (in CE) and EPA (in fasting TG) to a statistically significant, but nevertheless negligible, extent. We conclude that negative feedback inhibition by dietary LCP, if any, does not play an important role in the inability to augment notably DHA status by dietary ALA. The reach of a DHA plateau already at low dietary ALA intakes suggests that dietary DHA causes a non-functional DHA surplus, or is, alternatively, important for maintaining DHA status at a functionally relevant level.

Milk of patients with tightly controlled insulin-dependent diabetes mellitus has normal macronutrient and fatty acid composition.

The composition of macro- and micronutrients in milk from six patients with tightly controlled insulin-dependent diabetes mellitus [median glycosylated hemoglobin concentrations at parturition of 5.2% (range 4.9-5.3%, reference range 4.9-6.6%) and 6 wk thereafter of 6.1% (range 5.0-6.3%, reference range 5.0-6.4%) was compared with that from five control subjects. Milk samples were collected halfway through a single breast-feeding at days 3-5 (colostrum); 7, 9, and 10 (transitional milk); and 12, 15, 17, 21, 25, 29, and 35 (mature milk). We found no abnormalities in macronutrient (triglycerides, lactose, and protein), cholesterol, glucose, and myoinositol concentrations or fatty acid composition. Two of three longitudinally studied patients showed rather constant ratios between glucose concentrations in milk and capillary blood. The present data suggest that tight control corrects a multitude of milk abnormalities associated with moderate and poor control.

Intake of medium chain fatty acids (notably 12:0 and 14:0) from human milk in Antigua is not related to growth and does not cause energy wasting due to excessive beta-oxidation - abstract

The effect of postnatal intake of medium chain fatty acids (MCFA; C6-C14) from human milk on excessive beta-oxidation and growth was studied in Antigua. On day 23-28 a mean estimated intake of 8.9 g(range:3.8-16.6) of MCFA (notably 12:0 and 14:0) per litre did not cause excessive beta-oxidation, as derived from urinary excretion of ketone bodies and beta-hudroxybutyric acid. MCFA intake was not related to growth in the first 23-28 days. Intakes of as low as 2.7 g MCFA (notably 8:0 and 10:0) per litre from semisynthetic medium chain triglycerides are known to produce excessive beta-oxidation and urinary excretion of dicarboxylic acids (Rebouche et al, Am J. Clin. Nutri. 1990;52:820-824). It is concluded that, from a metabolic point of view, 12:0 and 14:0 from human milk belong to an intermediate subclass of MCFA that resembles long chain fatty acids greater than or equal to 16). Their uptake into adipose tissue may prevent hepatic oxidation, despite conceivable transportation of free 12:0 via the portal vein (AU)

Adipose tissue in foetuses, infants, children and adolescents in Curacao (Netherlands Antilles), its fatty acid content and composition: the fatty acid disappearance rate in childhood - abstract

There are uncertainties about the fatty acid (FA) disappearance rate in adipose tissue of infants. We therefore studied the adipose tissue FA content and composition in the foetal period in relation to samples obtained in infancy, childhood and adolescence. Adipose tissue samples were obtained in Curacao from Black foetuses and newborns (n = 42, gestation ages 22-43 weeks), and from infants, children and adolescents (n = 62, ages 0-19 years). FA was analysed by capillary gas chromatography. It was assumed that feeds of human milk or formula in the first ñ6 months accomplished 'pulse labelling' of newborn adipose tissue FA with medium chain saturated fatty acid (MC-SAFA), and that feeding of a "mixed" diet after 6 months of age constituted a 'wash-out' or 'chase' of the marker FAs. FA half-life was calculated from the disappearance rate of MC-SAFAs (AU)

Fat absorption in neonates: comparison of long-chain-fatty-acid and triglyceride compositions of formula, feces, and blood.

We studied malabsorption of fat in neonates who were fed either a lard-modified formula (n = 22, gestational age, 33.6 +/- 3.9 wk) or an unmodified formula (n = 14, gestational age, 34.1 +/- 3.7 wk). In both groups fecal lipid consisted almost completely (greater than 90%) of free fatty acids, whose composition was highly correlated with the corresponding formula's fatty acid composition [r = 0.96 (lard modified) and r = 0.99 (standard)]. Both groups had similar relative amounts and compositions of fecal cholesterol esters and triglycerides. Plasma and, to a lesser extent, erythrocyte membrane long-chain-fatty-acid compositions correlated with those of the corresponding formulas. We suggest that the extensive intestinal hydrolysis and limited absorption of dietary lipids is, at least partly, due to lipolysis in the colon. Appearance of triglycerides in the colon may be due to a rapid small-intestinal passage in relation to small-intestinal lipolysis.

A carbohydrate-rich diet not only leads to incorporation of medium-chain fatty acids (6:0-14:0) in milk triglycerides but also in each milk-phospholipid subclass.

We isolated phospholipid (PL) subclasses from milk of women in Dominica and Belize. Fatty acid (FA) compositions of PLs and total lipids were determined. In the total-lipid fraction Dominican milk showed higher relative amounts of medium-chain saturated fatty acids (MC-SAFAs; 6:0-14:0) and 22:6n-3 and lower amounts of long-chain saturated fatty acids (LC-SAFAs) and monounsaturated fatty acids (MUFAs). There was a positive relationship between the MC-SAFA content in total lipids and total PLs. Incorporation of MC-SAFAs in PLs occurred at the expense of LC-SAFAs, MUFAs, polyunsaturated fatty acids (PUFAs), and long-chain PUFAs with greater than or equal to 20 carbon atoms (LC-PUFAs greater than or equal to C20). Previous studies from Western countries revealed low amounts of MCSAFAs and high amounts of PUFAs and LC-PUFAs greater than or equal to C20 in milk PLs. Our data show that carbohydrate-rich diets give rise to incorporation of MC-SAFAs in PLs at the expense of PUFAs and LC-PUFAs greater than or equal to C20. The data are discussed in relation to the presumed origin of fat-globule membrane phospholipids.

A carbohydrate-rich diet not only leads to incorporation of medium-chain fatty acids (6:0-14:0) in milk triglycerides but also in each milk-phospholipid subclass

We isolated phospholipid (PL) subclasses from milk of women in Dominica and Belize. Fatty acid (FA) compositions of PLs and total lipids were determined. In the total-lipid fraction Dominican milk showed higher relative amounts of medium-chain saturated fatty acids (MC-SAFAs; 6:0-14:0) and 22:6n-3 and lower amounts of long-chain saturated fatty acids (LC-SAFAs) and monounsaturated fatty acids (MUFAs). There was a positive relationship between the MC-SAFA content in total lipids and total PLs. Incorporation of MC-SAFAs in PLs occurred at the expense of LC-SAFAs, MUFAs, polyunsaturated fatty acids (PUFAs), and long-chain PUFAs with o20 carbon atoms (LC-PUFAs oC20). Previous studies from western countries revealed low amounts of MC-SAFAs and high amounts of PUFAs and LC-PUFAs oC20 in milk PLs. Our data show that carbohydrate-rich diets give rise to incorporation of MC-SAFAs in PLs at the expense of PUFAs and LC-PUFAs oC20. The data are discussed in relation to the presumed origin of fat-globule membrane phospholipids. (AU)

Foetal adipose tissue fatty acid accretion - abstract

There are still uncertainties about the origin of the fatty acids (FA) deposited in the foetus, notably the percentage derived from the maternal circulation. This study describes a method to determine the amount of FA synthesized de novo in the foetus and the amount derived from the maternal circulation. Autopsy samples of subcutaeneous adipose tissue were obtained from 42 black foetuses and newborn infants. Samples of similar tissue were obtained from 50 pregnant women and 13 non-pregnant black women during surgery. FA analysis was done by gas chromatography. The accretion rate of FA in foetal adipose tissue was calculated by linear regression analysis of the FA data obtained from foetal/infant samples from the 22nd to 43rd week of gestation. The rate of foetal FA synthesized de novo in adipose tissue was calculated as the difference between the total foetal FA accretion rate and an estimate of the maternally derived FA. The latter was estimated from the values for accretion rates of saturated FA (SAFA), mono-unsaturated FA (MUFA), and polyunsaturated FA (PUFA) and total FA in foetal tissue, and the SAFA, MUFA and PUFA composition of adipose tissue in women (Table). Results show that of the total FA increment in foetal adipose tissue (22.7mg/g wet wt./week), 86.6 per cent was synthesized de novo by the foetus and the rest (13.2 per cent) was maternally derived (AU)

Influence of docosahexaenoic acid on cisplatin resistance in a human small cell lung carcinoma cell line.

In a sensitive, human, small cell lung carcinoma cell line (GLC4) and a cisplatin (CP)-resistant subline (GLC4-CP), the effect of co-culturing with docosahexaenoic acid (DCHA) on CP cytotoxicity was studied. Cells were cultured for 4 days, with 32 microM of DCHA added on days 1 and 3. Incorporation of DCHA into the cellular phospholipids was demonstrated by fatty acid analysis. Supplementation with DCHA led to almost a threefold decrease of resistance in GLC4-CP and had no influence on CP cytotoxicity in GLC4. After culturing with DCHA, cellular platinum (Pt); total Pt bound to DNA; and Pt-GG, Pt-AG, G-Pt-G, and Pt-GMP adduct contents increased in both lines, whereas interstrand cross-link formation was elevated only in GLC4-CP. These experiments demonstrate that DCHA reduces CP resistance. Although an effect on cellular membranes resulting in an increased CP uptake apparently was present, this mechanism does not seem to be responsible for resistance modulation. Rather, an effect on nuclear, probably DNA-related, structures is likely and leads to an increased formation of interstrand cross-links in GLC4-CP.

Effects of short-term high dose intake of evening primrose oil on plasma and cellular fatty acid compositions, alpha-tocopherol levels, and erythropoiesis in normal and type 1 (insulin-dependent) diabetic men.

In addition to their usual diet, nine Type 1 (insulin-dependent) diabetic men and ten male control subjects took 20 g d, alpha-tocopheryl acetate enriched evening primrose oil (14.45 g 18:2c,omega 6, 1.73 g 18:3c,omega 6, 400 mg d,alpha-tocopheryl acetate) daily for one week. At start, diabetic patients had more 14:0, 15:0 and 18:2c,omega 6, and less 16:0, 16:1c,omega 7, 18:1c,omega 7, 18:3c,omega 6, 20:3c,omega 9, 20:3c,omega 6, 20:4c,omega 6 and 22:6c,omega 3 in plasma, erythrocytes and/or platelets. Furthermore, they had lower 16:1c,omega 7/16:0, 18:1c,omega 7/16:0, and 20:4c,omega 6/20:3c,omega 6 ratios and a higher 20:3c,omega 6/18:3c,omega 6 ratio. In diabetic patients, alpha-tocopherol levels in erythrocytes were lower, whereas those in plasma were normal. In both groups, oil intake changed fatty acid profiles. Most markedly, 20:3c,omega 6 increased, whereas the ratios 20:3c,omega 6/18:3c,omega 6 and 20:4c,omega 6/20:3c,omega 6 decreased. 20:4c,omega 6 increased in control subjects, but not in diabetic patients. Erythrocytes and platelets responded differently in their fatty acid profiles. alpha-tocopherol rose in plasma and, although less for diabetic patients, in erythrocytes. In diabetic patients as well as in control subjects, erythrocyte count, haemoglobin level, mean corpuscular haemoglobin content and concentration increased and glycosylated haemoglobin percentage decreased without an apparent decline in blood glucose levels. Plasma beta-thromboglobulin and platelet factor 4 decreased, especially in diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of docosahexaenoic acid in vitro on intracellular adriamycin concentration in lymphocytes and human adriamycin-sensitive and -resistant small-cell lung cancer cell lines, and on cytotoxicity in the tumor cell lines.

An increase in the therapeutic effects of cancer chemotherapeutic agents and circumvention of drug resistance in cancer cells might result from an increase in the intracellular drug level. Alteration of the lipid domain of the cell membrane can result in a higher intracellular drug level. This alteration was achieved in human lymphocytes and in human adriamycin (ADR)-sensitive and -resistant small-cell lung carcinoma cells in vitro by incubation with docosahexaenoic acid (22:6). Incorporation of the fatty acid in cellular phospholipids was measured by gas chromatographic analysis. A significant increase of 22:6 could be reached without loss of viability in all 3 cell types. Incorporation was demonstrated notably in the phosphatidyl choline, phosphatidyl ethanolamine and phosphatidylserine, and was most pronounced in the phosphatidyl choline of the ADR-resistant line. After a 1-hr incubation with ADR, a 10-30% increase in intracellular adriamycin concentration was found in all 3 cell types previously incubated for 4 days with 22:6. After 1 hr incubation with ADR there was no increase in cytotoxicity in the sensitive cell line when measured by soft agar clonogenic assay and a partial reversal (52 to 14) of resistance factor (ratio of drug doses to produce 50% growth inhibition) in the resistant cell line. Increasing the time of ADR exposure from 1 to 4 hr further reduced the resistance factor to 8.6.

Rapid changes in serum, plasma and erythrocyte lipid compositions, and serum transaminase levels during continuous enteral hyperalimentation by carbohydrates alone.

Twelve normal men received twice their estimated basal energy requirement by a carbohydrate solution via a nasogastric catheter during 48 hours, followed by a seven-hour fast. Subsequently, in nine of them 0.5 mg epinephrine was given subcutaneously under ongoing fasting. During hyperalimentation, serum triglycerides, phospholipids, total and free cholesterol, phospholipids/free cholesterol ratio, and plasma free fatty acids decreased, whereas the percentage of free cholesterol increased. During fasting and subsequent epinephrine administration triglycerides and free fatty acids rose without reaching basal levels. Plasma and red blood cell (RBC) fatty acid composition already changed from two hours after the start of the feeding. Most markedly, a steady decrease in RBC 18:2c, omega 6, amounting to more than 17% of the basal value at the end of the observation period was found. Neither in plasma, nor in RBC a concomitant appearance of 20:3c, omega 9 was seen. In RBC, the relative amounts of the saturated fatty acids increased, whereas those of monounsaturated and polyunsaturated fatty acids decreased. RBC content of total fatty acids decreased and that of cholesterol increased. The ratios 16:1c, omega 7/16:0 and 18:3c, omega 6/18:2c, omega 6 in plasma, and 20:3c, omega 6/18:2c, omega 6 in plasma and RBC increased, whereas those of 18:1c, omega 7/16:1c, omega 7 and 20:3c, omega 6/18:3c, omega 6 in plasma decreased. After 48 hours feeding serum glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels were moderately increased and rose further during fasting. Thus, continuous enteral hyperalimentation by carbohydrates alone rapidly induces profound changes in serum-, plasma-, and RBC lipid compositions and serum parameters of hepatic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous quantification of total medium- and long-chain fatty acids in human milk by capillary gas chromatography with split injection.

Four different quantification methods for the capillary gas chromatographic determination of medium-chain fatty acids (6:0-12:0) and myristic acid in human milk samples, using a split injector, were compared. Odd-carbon-numbered fatty acids (5:0-17:0) were added as internal standards. Each medium-chain fatty acid and myristic acid was calculated on the basis of: the peak area of the internal standard with one methylene group less; the peak area of the internal standard with one methylene group more; half the sum of the peak areas of the internal standards with one methylene group less and more (bracketting method); the peak area of 17:0. The peak-area ratio of each analyte and 17:0 in a standard was found to be subject to an unacceptably high coefficient of variation. From the methods using internal standards with one methylene group more and less, the bracketting method was found to be the best, resulting in recoveries close to 100%, with the lowest coefficients of variation. The method was applied for the determination of the fatty acid composition of mature milk samples of 47 Curaçaoan women.

Comparison of the fatty acid composition of human milk from mothers in Tanzania, Curacao and Surinam.

Fatty acid composition of mature human milk from Curacao (Netherlands Antilles), Surinam and Tanzania was determined by capillary gas chromatography. In the Curacaoan samples the cholesterol and alpha- and gamma-tocopherol concentrations were also determined. Remarkable differences were found in the fatty acid composition of breastmilk fat from the three countries. The differences in the levels of medium chain fatty acids between Curacao and Tanzania, and between Curacao and Surinam were significant. The mean sum of the essential fatty acids linoleic acid and linolenic acid showed the highest values in Curacao (16.1 g per cent). Mean values for Tanzania and Surinam were 14.9 and 12.7, respectively. The mean level of the docosahexaenoic acid was higher in the Curacaoan and Surinam samples compared with that from Tanzania. In the Curacaoan breastmilk samples the concentrations of cholesterol and alpha- and gamma-tocopherol were about twice as high as those reported for Western countries.

Changes in fatty acid profiles of plasma, erythrocytes and polymorphonuclear leukocytes in induced hypothyroidism in man: indirect evidence for altered delta 6 desaturase activity.

Thirteen patients who were athyreotic as a consequence of ablation treatment for well-differentiated thyroid cancer were studied during triiodothyronine supplementation, and subsequently at the end of a two weeks withdrawal of this medication. Serum and plasma lipid concentrations, erythrocyte cholesterol content and plasma and erythrocyte total fatty acid patterns were measured. In addition, total fatty acid profiles of polymorphonuclear leukocytes of eight patients and scanning electron microscopic studies of erythrocytes of nine patients were made. We observed an increase of the serum concentrations of total and unesterified cholesterol and phospholipids in all patients. Except for two, all patients showed an increase in the serum triglyceride concentration. The relative amounts of 18:2c,omega 6 rose and those of 20:3c,omega 6 fell in all studied compartments. In addition, the relative amounts of all other omega 6 fatty acids, 22:6c,omega 3, 20:3c,omega 9, 16:0, 18:0, and total saturated fatty acids decreased in plasma, whereas the levels of all monounsaturated fatty acids increased in the erythrocytes. The level of 20:3c,omega 9 rose in the erythrocytes and the 20:3c,omega 9/20:4c,omega 6 ratio rose in the polymorphonuclear leukocytes. The erythrocyte total fatty acids and cholesterol content and their ratio did not change, nor was any alteration seen in the red cell morphology by scanning electron microscopy. This study reveals that the induction of hypothyroidism in man changes fatty acid patterns of plasma, erythrocytes and polymorphonuclear leukocytes. The nature of these alterations suggests especially a disturbance in the delta 6 desaturase activity. The data point to the possibility of a derangement of eicosanoid synthesis in hypothyroidism.

Capillary gas chromatographic profiling of total long-chain fatty acids and cholesterol in biological materials.

The profiling of total long-chain fatty acids and cholesterol in a variety of biological materials, using capillary gas chromatography with flame ionization detection, is described. The within-run precision and day-to-day precision for fifteen fatty acids and cholesterol in erythrocyte samples were investigated. Quantitative data on the analysis of amniotic fluid samples collected from women in the 30th to 38th week are given together with a correlation study on their lecithin/sphingomyelin and their palmitic acid/stearic acid ratios. In addition, the method was applied to lumbar cerebrospinal fluid, plasma, isolated leukemic blood cells and neuroblastoma tissue.