Plasmalogen phospholipids in plasma lipoproteins of normolipidemic donors and patients with hypercholesterolemia treated by LDL apheresis.

Recent evidence indicates that plasmalogen phospholipids are particularly sensitive to oxidation and may possess antioxidative properties. Approximately 4.4%-5.5% of phosphatidylcholine (PC), and 53%-60% of phosphatidylethanolamine (PE) consisted of the plasmalogen phospholipids, plasmenylcholine and plasmenylethanolamine, respectively, in whole plasma, low density lipoprotein (LDL) and high density lipoprotein (HDL) of 11 normolipidemic donors. Of total plasmalogen phospholipids in plasma, slightly more was associated with LDL particles (about 42%) than with HDL (36%). Plasmalogen phospholipid levels were analyzed in 12 patients with familial hypercholesterolemia (FH) regularly treated by LDL apheresis, of whom 6 were supplemented with vitamin E (alpha tocopherol, 400 IU/day), the remaining 6 not receiving the antioxidant. Before apheresis (pre), total plasmalogen phospholipid levels in plasma and LDL (expressed as mumol/mmol cholesterol of compartment) decreased as follows: patients receiving vitamin E > normolipidemia > patients not receiving vitamin E. In both hypercholesterolemic groups, the contents of plasmalogen phospholipids in whole plasma and LDL were 3-5-fold higher than those of vitamin E. Directly after apheresis (post), plasmalogen phospholipid levels in plasma were raised by about 50% in the two hypercholesterolemic groups, mostly due to increases in plasmenylethanolamine levels. Two days after apheresis (48 h post), plasmalogen contents were still elevated in plasma and red blood cell membranes of patients receiving vitamin E, while they had already reached pre-apheresis values in those not supplemented with alpha tocopherol. Molecular species of plasma diacyl phospholipids containing polyunsaturated fatty acids were elevated at pre in patients receiving vitamin E as compared to patients without supplementation. At 48 h post, LDL apheresis induced an increase in these molecular species only in patients receiving vitamin E. In conclusion, the contents of plasmalogen phospholipids in plasma lipoproteins are at least three times higher than those of vitamin E. LDL apheresis raises the level of plasmalogen phospholipids in plasma, the increase persisting longer in patients supplemented with vitamin E. Supplementation with vitamin E appears to protect plasmalogen phospholipids in plasma lipoproteins against oxidative degradation.

The biological significance of plasmalogens in defense against oxidative damage.

The phospholipid class of plasmalogens is ubiquitously found in considerable amounts as a constituent of mammalian cell membranes and of plasma lipoproteins. Plasmalogens are more susceptible to oxidative reactions compared to their fatty acid ester analogues, due to the reactivity of their enolether function. Studies on plasmalogen-deficient cell lines lead to the proposal that these ether lipids serve as endogenous antioxidants. No clear conclusions regarding the antioxidative effects of plasmalogens could be drawn from studies in patients of different ages with peroxisomal deficiency disorders. A defective peroxisomal plasmalogen synthesis is not necessarily associated with other defects in the metabolism of peroxisomes, as has been established in a cell line recently. In different mammalian tissues a decrease of plasmalogens with age was described. Moreover, an accumulation of plasmalogen oxidation products was measured in brain of old cattle compared to young ones. In pathologic conditions associated with oxidative stress like in spinal cord ischemia and reperfusion, plasmalogen levels varied inversely according to the oxidative burden. Oxidation products of plasmalogens increased with time of ischemia in infarcted porcine heart tissue. Enrichment of lipoproteins with plasmalogens increased their oxidative resistance, which was diminished in the case of LDL particles in patients with coronary arteriosclerosis. In red cell membranes plasmalogens were reduced with donor age and in hyperlipidemia. Under lipid lowering therapy with lovastatin an increase was observed, indicating a possible antioxidative impact of this treatment. Taken together, there is good evidence that plasmalogens are effective as endogenous antioxidants. However, more experimental approaches not confounded by other lipolytic processes are needed to establish this role of plasmalogens.

Decrease of cholesterol concentration in human erythrocyte ghosts in old age.

The lipid composition of the erythrocyte membrane ghosts of 95 relatively healthy elderly subjects was compared between four age groups: 70 to below 75 years (I), 75 to below 80 (II), 80 to below 85 (III) and 85 to below 90 years of age (IV). The molar ratio of phospholipid to cholesterol (PL/CH) in the erythrocyte ghosts increased with advancing age. Whilst PL levels did not change significantly, a decrease of membrane cholesterol was found. Therefore, the red cell membrane cholesterol seems to parallel the well-known pattern of variation of mean plasma total cholesterol and LDL cholesterol concentrations with age: an increase to a maximum in the sixth decade of life, and a decline thereafter. The processes which are responsible for these changes in cholesterol level with age have not been delineated. However, the findings suggest that one might get different results in studies of age-dependent membrane lipid alterations if rough age group divisions are made (below 30 years of age vs. over 70 years) or to subdivide the group of the elderly.

Plasmalogen phospholipids - facts and theses to their antioxidative qualities.

Fatty aldehyde dimethyl acetals (DMA) derived from plasma and erythrocyte membrane plasmalogen phospholipids of 109 donors, aged 25-91 years, were measured as weight percent of total phospholipid fatty acids and DMA. The age range from 70 to 90 years (n = 82) was divided into age groups of five years each. Cumulative distributions of the DMA values of these age groups, when compared with those of 17 younger persons (aged 25-41 years), revealed a tendency to higher DMA values in the youngest age group, and to lower values in the oldest one. Linear regressions were computed between age and hexadecanaldimethylacetal (16:0 DMA) or octadecanaldimethylactal (18:0 DMA) of erythrocyte membrane and plasma phospholipids. Statistically significant negative correlations with age were obtained. Because of their sensitivity to oxidation reactions, a role of plasmalogens as a natural antioxidant in oxidative defense mechanisms appears to be convincing. However, it will possibly be difficult to separate the effects of normal aging on the decline of plasmalogen phospholipid levels in some tissues from those of certain pathological conditions - including hyperlipidemia and atherosclerosis.

Plasmalogen levels in serum from patients with impaired carbohydrate or lipid metabolism and in elderly subjects with normal metabolic values.

The precise role played by plasmalogen phospholipids (PL) of lipoproteins and cell membranes is not well understood. However, they might act as endogenous antioxidants in defending cell membranes and lipoproteins from reactive oxygen species. A decline of plasmalogen concentrations has been observed in some tissues in normal aging and in some pathologic conditions. For healthy adults, we had reported negative correlations of age with serum plasmalogen PL derived heaxadecanal dimethylacetal (16:0DMA) or octadecanal dimethylacetal (18:0DMA) values. To mark off these age associated changes from disturbances in glucose or lipid metabolism, this study compares the 16:0DMA and 18:0DMA data of serum PL from 118 elderly subjects, aged 57-94 years, and grouped according to the disturbance of glucose or lipid metabolism. Using a new synthetic test mixture of 16:0DMA with oleic acid butylester as a quality control in gas chromatography, the highest 16:0DMA values were found in hypercholesterolemic subjects. However, related to the bulk of serum PL, were the plasmalogens possibly act as antioxidants, the highest values of 16:0DMA/PL were found in controls. A negative correlation of serum triglycerides (TG) with 16:0DMA was detected (n=118). The data suggest a closer association of low DMA values with elevated TG levels as compared to elevated plasma glucose or other serum lipid levels.

Effect of borage oil consumption on fatty acid metabolism, transepidermal water loss and skin parameters in elderly people.

Human skin is not able to biosynthesize gamma-linolenic acid (GLA, 18:3omega6) from the precursor linoleic acid (LA), or arachidonic acid (AA) from dihomo-gamma-linolenic acid (DHGLA). Dietary supplementation with GLA-rich seed oil of borage skips the step of hepatic 6-desaturation of fatty acids (FA) and, therefore, compensates the lack of these essential FA in conditions with impaired activity of delta 6-desaturase. Twenty-nine healthy elderly people (mean age 68.6 years), received a daily dose of 360 or 720 mg GLA for 2 months, using Borage oil in gelatine capsules (Quintesal 180, manufacturer Galderma Laboratorium GmbH, Freiburg, Germany). The effects of fatty acids derived from ingested borage oil capsules on skin barrier function were assessed by measurement of transepidermal water loss (TEWL). The consumption of borage oil induced a statistically significant improvement of cutaneous barrier function in the elderly people, as reflected in a mean decrease of 10.8% in the transepidermal water loss. Thirty-four percent of the people noted itch before borage oil consumption and 0% afterwards. Dry skin was claimed to be reduced from 42 to 14%, but no significant alteration of skin hydration was measured. The FA-composition of erythrocyte membrane phospholipids demonstrated an increase of GLA (+70%) and DHGLA (+18%) and a reduction of saturated and monounsaturated FA. There was no significant alteration in nervonic acid or in AA content, but an increase in the DHGLA/AA ratio (+23%). Thus, the consumption of borage oil by elderly people lead to alteration of FA metabolism and improved skin function.

Cholesterol and cholesterol sulphate concentration in the cell membrane complex of human scalp hair - A biomarker of aging?

Cell to cell cohesion in fully keratinized hair is mediated by a cell membrane complex which contains covalently bound (integral) hair lipids. The influence of aging on concentrations of integral cholesterol sulphate (CHSU) and cholesterol (CH) in human scalp hair shafts, and the relationship between hair and plasma lipids were examined in 50 subjects, aged 18 to 87 years, and in one case of Werner's syndrome. Hair CHSU concentrations were distributed normally and were significantly higher in male subjects with elevated plasma CH levels (>5.17 mmol/l) than in those with normal plasma CH levels (806+/-134 versus 624+/-155 nmol/g hair, p<0.001). Female subjects with elevated plasma CH levels had even lower hair CHSU, values (515+/-167 nmol/g hair, p<0.05) than men with normal plasma CH. The almost white hairs of the Werner's syndrome patient displayed low levels of CHSU, possibly indicating a precarious hair stability. A small but statistically significant linear correlation between donor age and integral CH in hair (n=51; y=97.7+0.9x; cc=0.32; p<0.05) was detected. No correlation between hair CHSU and age could be demonstrated. Since internal hair lipid concentrations do not correlate with plasma lipids, the age associated increase of hair CH as well as the observed gender differences in hair CHSU concentration may be related to alterations in the process of keratinization. Hair CH analysis seems to be of little significance in the clinical diagnosis of hypercholesterolemia.

Erythrocyte membrane changes associated with nutrition and aging--the role of plasmalogens.

Fatty aldehyde dimethylacetals (DMA) derived from human plasma and red cell plasmalogens of 20 female and 20 male donors, aged 70 years and over, and of 17 younger ones (12 male, 5 female), were measured as part of total phospholipid fatty acid methyl esters and DMA. There were no statistically significant changes in the hexadecanal DMA fractions of erythrocyte membranes with respect to donor age. In contrast, small degrees of correlation, though statistically significant, indicate a stochastic decline with donor age of erythrocyte octadecanal DMA and of plasma-derived hexadecanal DMA and octadecanal DMA levels. It is concluded that in the context of age-related changes not only the plasmalogen content of biomembranes has to be considered. Because of the sensitivity of plasmalogens to autoxidation, effects of oxidative damage and defense on membrane architecture, the degree of plasmalogen domain formation with its implication on membrane functions and the mechanisms regulating membrane turnover have to be also assessed.

The effect of different fat supplemented diets on the erythrocyte ghosts and plasma lipid composition of geriatric subjects.

The responses of the lipid composition of erythrocyte ghosts and plasma phospholipid fatty acids of 20 female donors, aged older than 70 years, to different margarine and butter supplemented diets were investigated. On a low level of daily caloric intake (1900 kcal) there were no changes in phospholipid and cholesterol content of the red cell membranes, but statistically significant changes were found in erythrocyte and plasma phospholipid fatty acid patterns. These results demonstrate the influence of the fatty acid composition of the dietary fats with special reference to saturated, trans-isomeric monoene, and polyunsaturated acids.

Plasma lipids and composition of red cells in four cases of Werner's syndrome.

Four cases of accelerated aging, known as Werner's syndrome (WS), are presented. Plasma lipid and lipoprotein findings and lipid compositions of red cell membranes are compared to those of old and young healthy people. Typical clinical findings, as reported in the literature, confirmed the diagnosis. Furthermore, an elevated osmotic fragility of red blood cells (RBC) was observed. RBC membranes of WS patients showed phospholipid concentrations similar to those found in people aged over 70 years, which have been reported to be lower than those of mature donors aged below 30 years. Fatty acid patterns of RBC membranes and plasma phospholipids were indicative of some disturbance in phospholipid subclass distributions in WS-patients.

Effective lovastatin therapy in elderly hypercholesterolemic patients - an antioxidative impact?

The effect of 3 months lovastatin therapy on serum lipids, apolipoproteins, alpha-tocopherol and red cell membrane fatty acid pattern was assessed in twelve elderly ambulatory patients (mean age 70.9+/-8.0 years) with hypercholesterolemia type IIa according to Fredrickson. After a run-in period of 4 weeks without drug therapy, the patients were given a daily dose of 20 mg lovastatin. The treatment resulted in statistically significant decreases in mean serum low density lipoprotein cholesterol (LDL-CH, -34%), in the atherogenic index LDL-CH/HDL-CH (-35%) and in the concentration of apolipoprotein B (-26%). No change in the vitamin E status, as related to plasma total lipids, was observed during the 3 months of therapy. The fatty acid pattern of phospholipids from red cell membranes showed an increase in linoleic acid metabolites and a decrease in the precursor linoleic acid, indicating an induction of fatty acid desaturases by lovastatin. In addition, an increase in the plasmalogen portion of erythrocyte membrane phospholipids was exhibited by increases in the proportion of fatty aldehyde dimethyl acetals (DMA) in the fatty acid pattern. The plasmalogens increase may counteract the slow but consistent decrease in their concentration in red cell membranes and human aortas with increasing donor age and in arteriosclerosis. Since plasmalogens may function as physiological antioxidants, the observed increase in DMA concentration might reflect a previously unrecognized antioxidative principle of a lovastatin therapy.

Study of telomere length and different markers of oxidative stress in patients with Parkinson's disease.

BACKGROUND: Many studies have shown that short telomere length (TL) is associated with high oxidative stress and various age-related diseases. Parkinson's disease (PD) is an age-related disease, and although its pathogenic mechanism is uncertain, oxidative stress is believed to be implicated in this pathology. The aim of this case-control study was to assess both TL and the different markers of oxidative stress in elderly patients with PD compared to age control subjects. METHODS: 20 PD patients and 15 age-matched controls, >65 years were studied. TL was measured by Southern blotting from DNA samples extracted from white blood cells. Superoxide dismutase (SOD) activity and plasma levels of total glutathione and protein carbonyls were determined. RESULTS: There was a trend for lower TL in PD patients: 6.06 ± 0.81 kb in PD versus 6.45 ± 0.73 kb in controls (p = 0.08). No significant difference was found between the two groups in terms of oxidative stress markers. In controls, age was the main determinant of telomere shortening (r = -0.547; p = 0.03) whereas, in PD patients, telomere shortening was mainly dependent on plasmatic concentrations of carbonyl proteins (r= -0.544; p=0.044). In PD patients, a negative association was observed between plasma carbonyl protein levels and SOD activity (r= -0.622, p=0.004). CONCLUSIONS: In PD, TL is shorter in presence of high oxidative stress as measured by carbonyl protein levels. The absence of telomere attrition with age among patients with PD could reflect a telomere regulation by mechanisms other than age.

[Gemfibrozil in the elderly. Effects on lipid metabolism]. / Gemfibrozil im Alter. Wirkungen auf den Fettsäurenstoffwechsel.

METHODS: Twenty patients with mixed hyperlipidemia type IIb were treated for two weeks with the lipid lowering agent gemfibrozil at a dose of 900 mg/day. The mean age of the 10 younger ambulatory patients was 32.3 +/- 4.1 years, that of the 10 geriatric inpatients 76.9 +/- 7.1 years. Fasting blood samples were drawn from the patients on days 1, 7 and 14, and plasma lipids and apolipoproteins determined. In addition, the plasma phospholipids were isolated and the fatty acid composition determined by gas chromatography. RESULTS: After only two weeks treatment with gemfibrozil, triglyceride and phospholipid plasma levels were significantly decreased. The therapeutic effects were more pronounced in the elderly patients, mainly female and most with diabetes mellitus, than in the younger, predominantly male hyperlipidemic patients. In accordance with the mechanism of action of gemfibrozil, the initially pathologically elevated levels of plasma free fatty acids in the geriatrics returned to normal. Furthermore, the fraction of long chain saturated fatty acids among the phospholipids became smaller, suggesting an impairment of chain elongation of fatty acids in the hepatic microsomes.

[Garlic as phytogenic antilipemic agent. Recent studies with a standardized dry garlic powder substance]. / Knoblauch als pflanzlicher Lipidsenker. Neuere Untersuchungen mit einem standardisierten Knoblauchtrockenpulver-Präparat.

Garlic (Allium sativum L.) is a commonplace drug. It is now available in the form of dragees made of garlic powder, standardized to 1.3% alliin. The lipid-lowering potential of such preparations has not been reviewed yet. In 7 out of 8 studies, including over 500 patients, a daily dose of 0.6 g to 0.9 g garlic powder reduced plasma cholesterol and triglyceride levels by 5 to 20 percent. The metabolic mechanisms of these reductions are not known.

[Tubal sterilization in the new unified Germany--results of a survey]. / Tubensterilisation in den neuen Bundesländern--Ergebnisse einer Umfrage.

A total of 4 statistical reviews of pelviscopic surgery had been issued in the Federal Republic of Germany until 1988. The five new federal states started such reviewing first in 1989 by quoting the number of tubal sterilization at 800. Our study, covering the period from May 31, 1991 to June 01, 1992 reveals an increase in pelviscopic surgery up to 20,000 with upward tendency. All 198 hospitals of the five new states were included in the inquiry and 133 of them took part in the survey. Out of 20,915 sterilization reported, 18,873 (90.3%) were performed by endoscopic surgery. Coagulation techniques such as monopolar and bipolar HF-methods, the endocoagulation according to Semm, and Laser techniques were available for endoscopic tubal sterilization. Mechanical methods such as a clip or Yoon's ring were used in less than 10% and were therefore of limited practical importance. Severe complications were reported in 32 cases.

The effect of a garlic preparation on the composition of plasma lipoproteins and erythrocyte membranes in geriatric subjects.

This study evaluated the effect of a dried garlic powder preparation, standardised to 1.3% alliin, on the composition of plasma lipoproteins and erythrocyte membranes. Forty volunteers, aged 70 years and over, took 600 mg of garlic powder per day for three months. In participants with initially normal plasma cholesterol levels (CH less than 200 mg/dl; n = 11) after three months of garlic tablet administration, little or no change in CH values was registered, as for most of the other parameters. In contrast, in volunteers with initially elevated CH levels (CH greater than 200 mg/dl, n = 29), the CH levels were reduced by -7.7% (p less than 0.001). This reduction took place primarily in the esterified cholesterol fraction (-12%, p less than 0.001), whereas free cholesterol concentrations were not altered significantly. Triglycerides (-15.9%, p less than 0.05) and plasma choline phospholipids (-4.6%, p less than 0.01) were also reduced. No change of the plasma LDL-CH to HDL-CH ratio was observed in this group. Based on the weight of lyophilised, haemoglobin-free erythrocytes, the mean membrane concentration of phospholipids and cholesterol in the total cohort (n = 40) increased by 5.7% (p less than 0.001) and 6.1% (p less than 0.01), respectively. These increases were more pronounced the lower the body mass indices (kg/m2) were, and the longer the duration of garlic administration was. The molar ratio of membrane phospholipids to cholesterol remained unchanged. The results are discussed with regard to a possible role of the garlic-induced membrane effects in the plasma lipid-lowering potency of garlic and preparations made from it.

Age-associated changes in integral cholesterol and cholesterol sulfate concentrations in human scalp hair and finger nail clippings.

In contrast to surface lipids originating from the sebaceous glands, membrane-forming integral lipids occur in keratinized tissues of skin, and skin appendages like fingernail plates or scalp hair. After removal of lipids of sebaceous origin by exhaustive solvent extraction, lyophilizing and hydrolyzing fingernail plate and scalp hair samples, fractions of integral cholesterol (CH) and cholesterol sulfate (CS) were quantified using gas chromatography. We studied these bound lipids and the serum lipids of 70 healthy subjects, aged 20.1 to 92.0 years. We observed higher amounts of CS in hair clippings of men than of women (775+/-241 vs 662+/-239 nmol/g hair, respectively). The highest amounts of CS were found in men with serum LDL-CH > 4.14 mmol/L; this subgroup also showed the highest CH values in fingernail clippings (2293+/-621 nmol/g nail). However, analysis of integral lipids of hair and fingernail plate clippings had little significance in detecting hypercholesterolemia in normal persons. An increase in integral CH levels in fingernail clippings with donor age was noted, independently of variations in serum CH or LDL-CH. This correlation proved to be significant in men (R=0.43), but not in women (R=0.38). In contrast, in women but not in men we found donor age correlated with internal CH of hair samples (R=0.43) and with CS of nail plates (R=-0.59), independently of serum CH or LDL-CH variations. This age-dependent decrease in CS levels might explain the previously observed higher incidence of brittle nails in women. Obviously, the metabolism of internal lipids CH and CS in fingernail and scalp hair differs between genders, and shows age-associated changes.

Methyl enol ethers as artefacts in capillary gas chromatographic profiles of aldehyde dimethyl acetals.

Methyl enol ethers are detected within the capillary gas chromatographic profiles of aldehyde dimethyl acetals derived from human red cell plasmalogens or from a synthetic aldehyde mixture. They arise from the dimethyl acetals via methanol elimination as artefacts of the injection technique. In a nutritional experiment, the probands showed a rising proportion of dimethyl acetals in the phospholipid fraction of their erythrocyte ghosts; this fact is seen as an effect of the lipid composition of the milk fat administered.

Role of plasmalogens in the enhanced resistance of LDL to copper-induced oxidation after LDL apheresis.

Extracorporeal reduction of plasma low density lipoproteins (LDLs) by LDL apheresis was shown to attenuate the proatherogenic influences of LDL, such as impairment of vasodilation and increased monocyte adhesion to the endothelium. In 16 patients with familial hypercholesterolemia, we analyzed whether LDL apheresis by the heparin precipitation procedure affected the oxidative resistance of LDL. Plasma LDL cholesterol concentrations were reduced by 65% after the apheresis. The lag time of copper-mediated LDL oxidation was increased from 103 to 117 minutes (P<0.0005). The LDL contents of alpha-tocopherol and beta-carotene, as well as the ratio of monounsaturated to polyunsaturated fatty acids in LDL, were not altered. However, the LDL apheresis induced a 15% increase in the LDL contents of plasmalogen phospholipids (P<0.0005), a class of ether phospholipids that were recently shown to prevent lipid oxidation. The phosphatidylcholine (PC) to lysoPC ratio was elevated by 16% after the apheresis (P<0.0005). The percent increase in LDL plasmalogen phospholipids showed a close association with the increased lag time after apheresis (P<0.0005). The LDL plasmalogen contents of the blood samples from patients and from normolipidemic donors were also positively related to the lag time (P<0.005). In vitro loading of LDL with plasmalogen phospholipids resulted in a prolongation of the lag time and an increase in the PC/lysoPC ratio. In conclusion, the rapid rise in LDL contents of plasmalogen phospholipids most probably causes the increase in lag time after LDL apheresis. Plasmalogens appear to play an important role in the oxidation resistance of LDL in vivo.