Dietary supplementation of alpha-linolenic acid in an enriched rapeseed oil diet protects from stroke.

Populations of Western countries are severely deficient in omega-3 intake, both in the form of alpha-linolenic acid (ALA) and the Long Chain derivatives (LC-n-3), Eicosa-Pentaenoic-Acid and Docosa-Hexaenoic-Acid. Omega-3 insufficiency is a risk factor for cardiovascular and cerebral diseases such as coronary heart disease and stroke. Stroke is a major cause of mortality and morbidity, and induces a significant socioeconomic cost and a marked increase in patient/family burden. To date, preventive treatments and neuroprotective drugs identified in preclinical studies failed in clinical trials, in part because of an inability to tolerate drugs at neuroprotective concentrations. Therefore testing alternative protective strategies, such as functional foods/nutraceuticals, are of considerable interest. We have previously demonstrated that a single injection of ALA reduced ischemic damage by limiting glutamate-mediated neuronal death, whereas repeated injections displayed additive protective benefits as a result of increased neurogenesis, synaptogenesis and neurotrophin expression. Because intravenous injections are not a suitable long-term strategy in humans, the present study investigated the effect of ALA supplementation by an experimental diet containing rapeseed oil (RSO, a rich source of ALA) as the only source of lipids for stroke prevention. We tested several experimental diets which included 5, 10, and 20% RSO-enriched diet and feeding paradigms (fresh diet was provided once or twice a week for 4 or 6 weeks). Our results showed that ALA supplemented diets are more sensitive to lipid peroxidation than a regular chow diet. Because the diet affected feeding behavior and animal growth, we defined concrete guidelines to investigate the effect of omega-3 supplementation on neuropathology. Among the different sets of experiments, animals fed with 10% and 20% RSO-enriched diet displayed a reduced mortality rate, infarct size and increased probability of spontaneous reperfusion in the post-ischemic period. In addition, a drastic reduction of lipid peroxidation levels was observed in the ischemic brain of RSO-fed animals. Overall, our findings provide new insights into the potential of employing rapeseed oil as a functional food/nutraceutical aiding in stroke prevention and protection.

Quantification of plasma lipoprotein fractions by wavelet transform time-domain data processing of the proton nuclear magnetic resonance methylene spectral region.

Quantitative analysis of lipoprotein major fractions, LDL, VLDL and HDL, is of great interest for medical purposes, for instance in liver or heart diseases, diet management or cancer. The presently available biochemical methods require time consuming ultracentrifugation. A potentially automated method is proposed, using time domain quantification by Wavelet Transform (WT-NMR) method. The aim of the present study was to evaluate, on a preliminary series of nine human plasmas, the potential interest of WT-NMR in the quantification of both NMR-visible lipids and total lipoprotein fractions. The correlation coefficients between low and intermediate density (LDL+IDL), very low density (VLDL) and high density (HDL) lipoprotein visible lipid quantifications, obtained on nine human plasmas with WT-NMR and standard biochemical methods, were 0.79, 0.84 and 0.92, respectively. For the total lipoprotein assay, i.e. including an estimation of non NMR-visible protein and free cholesterol, the correlation between WT-NMR and the biochemistry were 0.87 for LDL+IDL, 0.81 for VLDL and 0.88 for HDL.

Lp(a) levels and antiestrogen antibodies in women with and without thrombosis in the course of oral contraception.

Several reports have shown that lipoprotein(a) is associated with ischemic diseases. Two characteristics might explain this association. Firstly, Lp(a) is an LDL-like lipoprotein which may be implicated in the atherosclerotic process and secondly, Lp(a) possesses an additional apolipoprotein(a) whose structure is close to that of plasminogen and might confer to the molecule prothrombotic properties. It seemed of interest to see whether Lp(a) was a risk factor in oral contraceptive users with thrombotic complications, a group of young women with presumably little or no atherosclerosis. Three groups of women were compared: 25 of them served as controls and did not use oral contraceptives (OC) (group 1); 25 women were healthy current users of OC (group 2); 35 women suffered thrombotic complications in the course of OC (group 3). Mean levels of Lp(a), estimated by RID, were not found to be significantly different in the 3 groups: 19 +/- 18, 20 +/- 23 and 16 +/- 22 mg/dl, respectively. Levels above 30 mg/dl were similarly distributed. Among the other risk factors studied, antiestrogen antibodies were absent in group 1, present in 24% of group 2 and 71.4% of group 3 (P < 0.01). Serum cholesterol levels were similar in the 3 groups: 209 +/- 33, 220 +/- 41, 213 +/- 45 mg/dl respectively. Mean serum triglyceride levels were higher in group 2 than in group 1 (61 +/- 18 and 83 +/- 32, P < 0.01), and higher in group 3 than in group 2 (116 +/- 66 and 83 +/- 32, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in serum lipids and lipoproteins in 3 cases of heterozygous familial hypercholesterolemia treated by LDL apheresis on dextran sulfate-cellulose columns]. / Evolution des lipides et lipoprotéines sériques dans 3 cas d'hypercholestérolémie familiale hétérozygote traités par aphérèse des LDL sur colonne de sulfate de dextran-cellulose.

Three patients with heterozygote type IIa hyperlipoproteinemia were treated by specific LDL apheresis with a dextran sulfate-cellulose column every two weeks. Each apheresis resulted in a fall in total cholesterolemia of about 50 p. 100 with a parallel fall in apoprotein B. The average drop of 15 p. 100 in HDL-cholesterol appeared to be due to the hemodilution induced at the end of apheresis. After two months, cholesterol and apoprotein B concentrations before removal were 15 p. 100 lower than baseline values. Treatment was well tolerated. These findings appear encouraging for the treatment of heterozygote forms of familial hyperlipoproteinemia resistant to chemotherapy.

Blood changes in sex steroid hormone users. Circulating immune complexes induced by estrogens and progestogens and their relation to vascular thrombosis.

Oral contraceptives (OC) have been shown to induce in some women antiethinylestradiol antibodies which may be detected as circulating immune complexes by precipitation in ammonium sulphate at 25% saturation (CIC.AS). A reevaluation of the presence of CIC.AS in 644 women either receiving sex steroid hormones or not was made, and the respective role of estrogens and progestogens investigated, together with the influence of the dose. The study confirmed that CIC.AS levels were significantly different in controls (442 +/- 246 micrograms/ml serum), healthy gonadal hormone users (754 +/- 700 micrograms) and users with thrombosis (1331 +/- 1099 micrograms/ml). These results indicated that: 1. CIC.AS could be induced by synthetic estrogens as well as progestogens, but not by non-synthetic hormones; 2. the induction of CIC.AS seemed poorly dose-related, and 3. was not correlated with the duration of use; 4. in reactive women, high CIC.AS levels occurred as soon as 3 weeks after the beginning of synthetic gonadal hormones use, persisted throughout treatment and decreased slowly when discontinued; 5. in women with thrombosis CIC.AS were more frequently detected (64.7%) than in healthy users (32.2%) P less than 0.001. The importance of the immunologic changes as a risk factor in thrombosis in OC users was evaluated in comparison with other predisposing factors and tobacco smoking.

PIP: Oral contraceptives (OCs) have been shown to induce antiethinyl estradiol antibodies in some women which may be detected as circulating immune complexes by precipitation in ammonium sulphate at 25% saturation (CIC.AS). A reevaluation of the presence of CIC.AS in 644 women either receiving sex steroid hormones or not was made, and the respective role of estrogens and progestogens investigated, together with the influence of the dose. The study confirmed that CIC.AS levels were significantly different in controls (442 +or- 246 mcg/ml serum), healthy gonadal hormone users (754 +or- 700 mcg) and users with thrombosis (1331 +or- 1099 mcg/ml). These results indicated that: 1) CIC.AS could be induced by synthetic estrogens as well as progestogens but not by nonsynthetic hormones; 2) the induction of CIC.AS seemed poorly dose-related; and 3) the induction was not correlated with the duration of use; 4) high CIC.AS levels occurred as soon as 3 weeks after the beginning of synthetic gonadal hormone use in reactive women and persisted throughout treatment and decreased slowly when discontinued; and 5) CIC.AS was detected more frequently (64.7%) in women with thrombosis than in healthy users (32.2%), P0.001. The importance of the immunologic changes as a risk factor in thrombosis in OC users was evaluated in comparison with other predisposing factors and tobacco smoking.

[Immunochemical study of the lipoprotein substance Pg (author's transl)]. / Etude immunochimique du site lipoprotéique Pg.

Site Pg is an antigenic determinant which is present on the surface of serum lipoproteins and reacts with an antilpoprotein myelomatous immunoglobulin, the IgA, Ger. Firstly site Pg is extracted from LDL with the major part of lipids, by an ether-methanol mixture at 6 p. 100. Then the organic substrate obtained is evaporated under vacuum and dissolved in saline before being submitted to an extraction by ehter only. Under these conditions, site Pg remains in the aqueous phase. A polyacrylamide gel filtration on Biogel P2 allows then to separate the substance which reacts with IgA Ger. anti-Pg, from the aqueous phase. The identification of site Pg allowed us to recognize the presence of galactose, phosphorus and choline, and to evaluate its molecular weight of about 330. The reactivity of site Pg with IgA anti-Pg was measured by inhibition of passive hemagglutination and fluorescence quenching. The association constant of site Pg with the whole IgA Ger. or with its Fab fragment could thus be calculated (1.6 10(5) M-1 with the whole IgA; 2.3 10(5) M-1 with the Fab fragment). We showed also that if phosphorylcholine plays an immunodominant role, the presence of sugar seems necessary, since the association constant of the whole IgA Ger. with site Pg is higher than that of IgA Ger. with phosphorylcholine alone.

A new serum lipoprotein associated erythrocyte antigen which reacts with a monoclonal IgM. The stored human red blood cell SHRBC antigen.

A monoclonal IgM (IgM) was found to react with stored human red blood cells (SHRBC) and human low density lipoprotein (LDL). IgM Re Fab fragment was reactive. SHRBC antigen was present, in a hidden state, in all fresh human ABO erythrocytes studies; it was not present in fresh or stored animal RBC. Cross reactivity of SHRBC and LDL antigens against IgM Re and IgM Re Fab was demonstrated. In contrast with SHRBC antigen, LDL antigen has no species specificity and was also found in rabbit and rat LDL. Furthermore, cross-reacting soluble inhibitors were also found in human saliva, and in a small molecule fraction issued from human and rabbit serum. The IgM Re also reacted with human and animal glomerular membrane. These findings are suggestive of two closely related but not identical antigens: a human specific SHRBC antigen and a LDL-associated, SHRBC-like antigen, which is a secreted, non-human specific substance. The former is part of the human RBC structure, the latter is a soluble molecule which may be found in saliva and in serum where it may be free or bound to LDL; it also binds to glomerular membranes.