![]() |
|
|


Hugh Sinclair Unit of Human Nutrition, University of Reading, Reading, UK;
* Medical Research Council Cardiovascular Research Group, Wolfson Institute of Preventive Medicine, London, UK; and
Institute of Human Nutrition, University of Southampton, Southampton, UK
3To whom correspondence should be addressed. E-mail: c.m.williams{at}reading.ac.uk.
| ABSTRACT |
|---|
|
|
|---|
-linolenic acid (ALA) can be converted to long-chain (n-3) PUFA in humans and may potentially reproduce the beneficial effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on risk factors for coronary heart disease (CHD). This study compared the effects of increased intakes of ALA with those of dietary EPA and DHA on blood coagulation and fibrinolytic factors in fasting subjects. A placebo-controlled, parallel study was conducted in 150 moderately hyperlipidemic subjects, age 2572 y. Subjects were randomly assigned to one of five interventions and consumed a total intake of 0.8 or 1.7g/d EPA+DHA, 4.5 or 9.5g/d ALA or control (linoleic acid; LA) for 6 mo. Fatty acids were incorporated into 25 g of fat spread, which replaced the subjects normal spread and three capsules. Long-term supplementation with either dietary EPA+DHA or estimated biologically equivalent amounts of ALA did not affect factors VIIa, VIIc, VIIag, XIIa, XIIag, fibrinogen concentrations, plasminogen activator inhibitor-1 or tissue plasminogen activator activity compared with the control. (n-3) PUFA of plant or marine origin do not differ from one another or from LA in their effect on a range of blood coagulation and fibrinolytic factors.
KEY WORDS:
-linolenic acid eicosapentaenoic acid docosahexaenoic acid Factor VIIc Factor XII
Blood coagulation and fibrinolysis play an important role in the development and complications of coronary heart disease (CHD). Fibrinogen concentration (1,2), tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) antigen concentrations (3) are positively associated with CHD incidence. High factor VII coagulant activity (FVIIc) has also been reported to increase CHD risk in men in the Northwick Park Heart Study (1), although this finding was not replicated in more recent studies (4,5).
Individual studies have shown that supplementation with fish oils rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can alter coagulation and fibrinolysis variables, although there is little agreement on the overall effect of (n-3) PUFA on these variables (6). The intakes of EPA+DHA used in these studies (> 3 g/d) (711) are generally greater than levels that can be accomplished through dietary means, and there is little information on the effects of more modest increases in intakes.
One of the aims of the present study was therefore to examine the effects of modest increases in EPA+DHA, given long term, on a range of coagulation and fibrinolytic variables. A further aim was to study the effects on these variables of the precursor (n-3) PUFA.
-Linolenic acid (ALA), a plant-derived (n-3) fatty acid found in a wide variety of foods including commercial vegetable oils, can be converted by alternate desaturation and elongation to EPA and DHA in humans (12,13). Interest in potential cardioprotective effects of ALA was raised by findings from a secondary prevention trial that reported a substantial reduction in coronary events and death in subjects following a Mediterranean style diet that also included an ALA-rich margarine (14). As with reported effects of EPA+DHA in the GISSI (15) secondary prevention trials, the benefits were observed early in the trial, suggesting either an improved hemostatic profile or an antiarrhythmic effect.
Few studies have investigated the effects of ALA and none have noted any significant change in a range of blood coagulation or fibrinolysis factors (11,16,17). However, in all of these studies, supplementation was relatively short term (46 wk), which may not have allowed sufficient time for accumulation of long-chain (LC) (n-3) PUFA from the desaturation and elongation of ALA. The present study is the first to undertake a comparison of the effects of low dose EPA+DHA with increased intakes of ALA. The prolonged time period of supplementation and the measurement of FXII activation in response to (n-3) fatty acids are also important features of the study.
| SUBJECTS AND METHODS |
|---|
|
|
|---|
Moderately hyperlipidemic, but otherwise healthy men and women aged 2572 y were recruited from the local population and provided a screening blood sample after an overnight fast. Exclusion criteria for participation in the study included: cardiovascular, liver or other endocrine disease; diabetes; pregnancy/lactation; smoking >15 cigarettes/d; BMI < 20 and > 32 kg/m2; regular use of hypolipidemic or anti-inflammatory medication, aspirin, anticoagulants, fatty acid or antioxidant supplements; eating >2 portions of oily fish/wk (
180 g/wk); and vegetarianism. Moderate hyperlipidemia was defined as fasting total cholesterol (TC) 4.68.0 mmol/L and fasting triacylglycerol (TAG) 0.83.2 mmol/L. The study was approved by the University of Reading Ethics and Research Committee and West Berkshire Health Authority Ethics Committees (UK). Each volunteer gave written consent.
The study was a double-blind, placebo controlled, parallel study (18). Before the 6-mo intervention period with the test margarine/capsules, all participants consumed the control margarine and capsules for 1 mo. Subjects were then assigned to one of the five dietary treatment groups (n = 30 per group) by blocked stratified randomization with the groups matched for fasting TAG, age and sex. Sample size (n = 150) was estimated using power calculations based on the predictive TAG-lowering effect of 1.5g/d EPA+DHA, with 80% power and 5% significance. The study was run in three cohorts of
50 subjects. Blood samples were taken at 0, 3 and 6 mo, after an overnight fast.
Dietary intervention.
The aim of the dietary intervention was to supplement the diet with modest amounts of EPA+DHA or biologically equivalent levels of the precursor, ALA, based on the existing literature, which suggests that 7 g ALA
1 g EPA+DHA in raising tissue LC (n-3) PUFA concentrations (12,19,20). The target intakes of EPA+DHA in the two fish oil intervention groups were 0.7 and 1.5 g/d, respectively, whereas target intakes of ALA in the two ALA-supplemented groups were 5.0 and 10.0 g/d, respectively. The target intakes in the (n-3) PUFA-supplemented groups and the control were calculated to include the estimated average contribution from the background UK diet of EPA+DHA (0.2 g/d) and ALA (1.5 g/d) (21).
The intervention was provided as 25 g/d of specially formulated spreads (85% fat) and three capsules. The control margarine was a typical (n-6) PUFA-rich margarine based mainly on sunflower and safflower oil (Table 1). The EPA+DHA enriched margarine was a sunflower- and fish oil-based margarine containing 0.5 g EPA+DHA/25 g portion. For the higher dose EPA+DHA intervention, three fish oil capsules containing a total of 0.8 g EPA+DHA were taken in addition to the fish oil margarine as described above. To maintain the double-blind aspect of the study, all other intervention groups were provided with placebo capsules. The moderate and high ALA interventions were based on rapeseed, linseed and sunflower oils. The amount of vitamin E in the interventions was standardized according to intake of unsaturated bonds, based on the amount and type of PUFA present (22).
|
Fasting venous samples were collected into a 1 x 4.5 mL sodium citrate tube (Becton Dickinson, Plymouth, UK) for analysis of factors VIIa, VIIc, VIIag, XIIa, XIIag and fibrinogen, a 1 x 2 mL sodium citrate tube for analysis of PAI-1 and a 1 x 2 mL acid citrate tube for analysis of tPA. Samples were centrifuged immediately at 1600 x g for 15 min and plasma was stored at -70°C. Samples from each subject were analyzed at the end of each cohort in a single batch to minimize variability, and all analyses of hemostatic factors were carried out at the Wolfson Coagulation Laboratory (MRC). FVIIa was measured by a one-stage clotting assay (23). FVIIc was measured by a one-stage semiautomated bioassay using rabbit brain thromboplastin (Diagen, Thame, Oxon, UK) and a FVII-deficient plasma, described elsewhere (24). FVIIag was determined using an ELISA with specific rabbit antihuman FVII antibody (Asserachrom VII:Ag; Diagnostico Stago, Cedex, France). FXIIa was measured by ELISA (Activated FXII assay kit FAFT200; Axis-Shield, Dundee, UK). FXIIag was measured both by ELISA using paired antibodies (FXII-EIA) and by Laurell "Rocket" electroimmunoassay using goat anti-human FXII IgG (GAFXII-AG; both from Enzyme Research Laboratories, Swansea, UK). Fibrinogen was measured using a thrombin clotting assay, modified from Clauss (25), using standard plasma (Immuno Vienna, Austria). TPA and PAI-1 activities were measured using the Coatest PAI-1 assay kit (Chromogenix Coatest PAI; Quadratech Diagnostics, Epsom, Surrey, UK) using different methodologies and differently anticoagulated samples. All assays were performed in duplicate; all samples from individual subjects were assayed at the same time. The intra-assay CV for FVIIa, FVIIc, FVIIag and FXIIa were 11.1, 2.2 3.5 and 5.4%, respectively. The intra-assay CV for fibrinogen, t-PA and PAI-1 were 4.4, 4.2 and 2.4%, respectively.
Statistics.
Results are expressed as means and SD for all variables unless otherwise indicated. FVIIa and PAI-1 were log-transformed before analysis and results expressed as geometric means with approximate SD. Plasma tPA activity was expressed as median and range. Differences between treatments at each time point were tested by ANOVA. For tPA, the nonparametric Kruskal-Wallis test was used. To take account of any baseline differences, we expressed 3- and 6-mo concentrations as a percentage of the baseline concentration and repeated-measures ANOVA models were used to determine the effect of treatment over time. A diet x time interaction term was fitted in each model to determine whether the diet effect was constant across all time points. Changes from baseline to 6 mo were assessed using paired t tests. All statistical tests were carried out using statistics package STATA version 7.0 (Stata, College Station, TX).
| RESULTS |
|---|
|
|
|---|
|
|
| DISCUSSION |
|---|
|
|
|---|
There is little agreement on the effects of LC (n-3) PUFA on clotting factors and fibrinolysis (6). In the present study, more modest intakes of EPA+DHA over a long period did not affect FVIIc activity in fasting subjects. These findings are in line with several studies (7,10,31), although another reported changes consistent with FVII activation (32). Similarly, there is no consensus on the overall effect of LC (n-3) PUFA on fibrinogen or PA11 concentrations although long-term intervention studies do not support effects of LC (n-3) PUFA on these factors. Feeding 4 g/d of fish oil concentrate to coronary artery disease patients for 9 mo did not affect fibrinogen concentration of FVII or PAI-1 activity, although a significant increase in PAI-1 antigen was observed (10). Supplementation with 2 g/d EPA+DHA for 5 mo did not affect tPA activity or tPA or PA11 concentrations (33). Our results support the lack of biologically important effects on these factors at dietary achievable levels of (n-3) PUFA.
FXIIa has been shown to be increased in men at high risk of CHD (34). At present, the investigation of LC (n-3) PUFA effects on FXII has been confined to one clinical trial (35) that reported no effect of fish oil on FXIIa in parenterally supplemented patients. In subjects consuming a diet rich in rapeseed oil, increased ALA intake did not affect FXIIc activity or FXIIa concentrations compared with a typical SFA-rich diet (16). This study supports the absence of any effect on FXII activity or concentration of either plant- or marine-derived (n-3) PUFA compared with LA as a control.
We previously reported a difference (P < 0.05) in the change in plasma TAG in subjects who consumed 1.7 g/d EPA+DHA diet (-7.7%) compared with those in the 9.5 g/d ALA group (+10.9%) (18). Similar directional trends for change in FVIIc were observed with decreases in the EPA+DHA groups and increases in the ALA groups, demonstrating internal consistency between the lipid and hemostatic results.
In summary, there was no significant long-term influence on the variables measured of either moderate doses of EPA+DHA or biologically equivalent amounts of ALA in moderately hyperlipidemic subjects compared with an (n-6) fatty acid control. However, more sensitive markers of in vivo hemostasis are required to confirm this. Overall, the results are in line with a growing consensus that dietary fat quality is not a strong regulator of many of the markers of blood coagulation and fibrinolysis (36) and that an antiarrhythmic effect of (n-3) PUFA (14,15) may be responsible for the protective action of LC (n-3) PUFA on CHD mortality at low levels of intake.
| FOOTNOTES |
|---|
-linolenic acid and long chain (n-3) polyunsaturated fatty acids on risk factors for coronary heart disease.
2 Supported by a grant from the Department for Environment, Food and Rural Affairs (UK), Biotechnology and Biological Sciences Research Council, Roche Vitamins, Limited, Basel, Switzerland and Unilever Research, Vlaardingen, under the Agri-Food LINK programme (AFQ111). The spreads were prepared by Unilever Research and the capsules by Roche Vitamins, Limited. ![]()
4 Abbreviations used: ALA,
-linolenic acid; CHD, coronary heart disease; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; LA, linoleic acid; LC, long chain; MUFA, monounsaturated fatty acid; PAI-1, plasminogen activator inhibitor-1; PL, phospholipid; SFA, saturated fatty acid; TAG, triacylglycerol; TC, total cholesterol; tPA, tissue plasminogen activator. ![]()
Manuscript received 5 December 2002. Initial review completed 19 December 2002. Revision accepted 27 March 2003.
| LITERATURE CITED |
|---|
|
|
|---|
1. Meade, T. W., Mellows, S., Brozovic, M, Miller, G. J., Chakrabarti, R. R., North, W. R., Haines, A. P., Stirling, Y., Imeson, J. D. & Thompson, S. G. (1986) Haemostatic function and ischaemic heart disease: principal results of the Northwick Park Heart Study. Lancet 2:533-537.[Medline]
2. Kannel, W. B., Wolf, P. A., Castelli, W. P. & DAgostino, R. B. (1987) Fibrinogen and risk of cardiovascular disease. The Framingham Study. J. Am. Med. Assoc. 258:1183-1186.
3. Folsom, A. R., Aleksic, N., Park, E., Salomaa, V., Juneja, H. & Wu, K. K. (2001) Prospective study of fibrinolytic factors and incident coronary heart disease: The Atherosclerosis Risk in Communities (ARIC) Study. Arterioscler. Thromb. Vasc. Biol. 21:611-617.
4. Folsom, A. R., Wu, K. K., Rosamond, W. D., Sharrett, A. R. & Chambless, L. E. (1997) Prospective study of hemostatic factors and incidence of coronary heart disease: The Atherosclerosis Risk in Communities (ARIC) Study. Circulation 96:1102-1108.
5. Cooper, J. A., Miller, G. J., Bauer, K. A, Morrissey, J. H., Meade, T. W., Howarth, D. J., Barzegar, S., Mitchell, J. P. & Rosenberg, R. D. (2000) Comparison of novel hemostatic factors and conventional risk factors for prediction of coronary heart disease. Circulation 102:2816-2822.
6. Knapp, H. R. (1997) Dietary fatty acids in human thrombosis and hemostasis. Am. J. Clin. Nutr. 65:1687S-1698S.
7. Brox, J. H., Killie, J. E., Osterud, B., Holme, S. & Nordoy, A. (1983) Effects of cod liver oil on platelets and coagulation in familial hypercholesterolemia (type IIa). Acta Med. Scand. 213:137-144.[Medline]
8. Hansen, J. B., Olsen, J. O., Wilsgard, L. & Osterud, B. (1989) Effects of dietary supplementation with cod liver oil on monocyte thromboplastin synthesis, coagulation and fibrinolysis. J. Intern. Med. Suppl. 225:133-139.
9. Hansen, J., Grimsgaard, S., Nordoy, A. & Bonaa, K. H. (2000) Dietary supplementation with highly purified eicosapentaenoic acid and docosahexaenoic acid does not influence PAI-1 activity. Thromb. Res. 98:123-132.[Medline]
10. Eritsland, J., Arnesen, H., Seljeflot, I. & Kierulf, P. (1995) Long-term effects of (n-3) polyunsaturated fatty acids on haemostatic variables and bleeding episodes in patients with coronary artery disease. Blood Coagul. Fibrinolysis 6:17-22.[Medline]
11. Freese, R. & Mutanen, M. (1997) Alpha-linolenic acid and marine long-chain (n-3) fatty acids differ only slightly in their effects on hemostatic factors in healthy subjects. Am. J. Clin. Nutr. 66:591-598.
12. Emken, E. A., Adlof, R. O. & Gulley, R. M. (1994) Dietary linoleic acid influences desaturation and acylation of deuterium-labeled linoleic acid and linolenic acids in young adult males. Biochim. Biophys. Acta 1213:277-288.[Medline]
13. Pawlosky, R. J., Hibbeln, J. R., Novotny, J. A. & Salem, N., Jr (2001) Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans. J. Lipid Res. 42:1257-1265.
14. De Lorgeril, M., Renaud, S., Mamelle, N., Salen, P., Martin, J.-L., Monjaud, I., Guidollet, J., Touboul, P. & Delaye, J. (1994) Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease. Lancet 343:1454-1445.[Medline]
15. GISSI-Prevenzione Trial (1999) Gruppo Italiano per lo Studio della Sopravvivenza nellInfarto miocardico. Dietary supplementation with (n-3) polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI trial. Lancet 7:447-455.
16. Junker, R., Kratz, M., Nuefeld, M., Erren, M., Nofer, J. R., Schulte, H., Nowak-Gottl, U., Assmann, G. & Wahrburg, U. (2001) Effects of diets containing olive oil, sunflower oil or rapeseed oil on the hemostatic system. Thromb. Haemost. 85:280-286.[Medline]
17. Allman-Farinelli, M. A., Hall, D., Kingham, K., Pang, D., Petocz, P. & Favaloro, E. J. (1999) Comparison of the effects of two low fat diets with different alpha-linolenic:linoleic acid ratios on coagulation and fibrinolysis. Atherosclerosis 142:159-168.[Medline]
18. Finnegan, Y. E., Minihane, A. M., Leigh-Firbank, E. C., Kew, S., Meijer, G. W., Muggli, R., Calder, P. C. & Williams, C. M. (2003) Plant- and marine-derived n-3 polyunsaturated fatty acids have differential effects on fasting and postprandial blood lipid concentrations and on the susceptibility of LDL to oxidative modification in moderately hyperlipidemic subjects. Am. J. Clin. Nutr. 77:783-795.
19. Sanders, T. A. B. & Roshanai, F. (1983) The influence of different types of
-3 polyunsaturated fatty acids on blood lipids and platelet function in healthy volunteers. Clin. Sci. (Lond.) 64:91-99.[Medline]
20. Indu, M. & Ghafoorunissa, (1992) (n-3) Fatty acid in Indian diets- comparison of the effect of precursor (alpha-linolenic acid) vs product (long chain n-3 polyunsaturated fatty acids). Nutr. Res. 12:569-582.
21. Gregory, J., Foster, K., Tyler, H. & Wiseman, M. (1990) The Dietary and Nutritional Survey of British Adults: A Survey of the Dietary Behavior, Nutritional Status and Blood Pressure of Adults Aged 16 to 64 Living in Great Britain 1990 HMSO London, UK.
22. Muggli, R. (1994) Physiological requirements of vitamin E as a function of the amount and type of polyunsaturated fatty acid. Galli, C. Simpolous, A. P. Tremoli, E. eds. Fatty Acids and Lipids: Biological Aspects 1994:166-168 Karger Basel, Switzerland. .
23. Morrissey, J. H., Macik, B. G., Neuenschwander, P. F. & Comp, P. C. (1993) Quantitation of activated factor VII levels in plasma using a tissue factor mutant selectively deficient in promoting factor VII activation. Blood 81:734-744.
24. Miller, G. J., Stirling, Y., Esnouf, A. P., Heinrich, J., van de Loo, J., Kienast, J., Wu, K. K., Morrissey, J. H., Meade, T. W., Martin, J. C., Imeson, J. D., Cooper, J. A. & Finch, A. (1994) Factor VII-deficient substrate plasma depleted of protein C raise the sensitivity of the factor VII bio assays to activated factor VII: an international study. Thromb. Haemost. 71:38-48.[Medline]
25. Clauss, A. (1957) Gerinnungsphysiologische Schnellmethode zur Bestimmung des Fibrinogens. Acta Haematol. 17:237-246.[Medline]
26. Bemelmans, W. J., Broer, J., Feskens, E. J., Smit, A. J., Muskiet, F. A., Lefrandt, J. D., Bom, V. J., May, J. F. & Meyboom-de Jong, B. (2002) Effect of an increased intake of alpha-linolenic acid and group nutritional education on cardiovascular risk factors: The Mediterranean Alpha-linolenic Enriched Groningen Dietary Intervention (MARGARIN) study. Am. J. Clin. Nutr. 75:221-227.
27. Ezaki, O., Takahashi, M., Shigematsu, T., Shimamura, K., Kimura, J., Ezaki, H. & Gotoh, T. (1999) Long term effects of dietary
-linolenic acid from perilla oil on serum fatty acids composition and the risk factors of coronary heart disease in Japanese elderly subjects. J. Nutr. Sci. Vitaminol. 45:759-772.
28. Larsen, L. F., Jespersen, J. & Marckmann, P. (1999) Are olive oil diets antithrombotic? Diets enriched with olive, rapeseed, or sunflower oil affect postprandial factor VII differently. Am. J. Clin. Nutr. 70:976-982.
29. Chan, J. K., Mc Donald, B. E., Gerrard, J. M., Bruce, V. M., Weaver, B. J. & Holub, B. J. (1993) Effect of dietary
-linolenic acid and its ratio to linoleic acid on platelet and plasma fatty acids and thrombogenesis. Lipids 28:811-817.[Medline]
30. Kelley, D. S., Nelson, G. J., Love, J. E., Branch, L. B., Taylor, P. C., Schmidt, P. C., Mackey, B. E. & Iacono, J. M. (1993) Dietary
-linolenic acid alters tissue fatty acid composition, but not blood lipids, lipoproteins or coagulation status in humans. Lipids 28:533-537.[Medline]
31. Sanders, T. A., Vickers, M. & Haines, A. P. (1981) Effect on blood lipids and haemostasis of a supplement of cod-liver oil, rich in eicosapentaenoic and docosahexaenoic acids, in healthy young men. Clin. Sci. (Lond.) 61:317-324.[Medline]
32. Hornstra, G. (1982) Effect of fish oil feeding on arterial thrombosis, platelet function and blood coagulation. Hornstra, G eds. Dietary fats, prostanoids and arterial thrombosis 1982 Martinus Nijhoff The Hague, Netherlands. .
33. Hellsten, G., Boman, K., Saarem, K., Hallmans, G. & Nilsson, T. K. (1993) Effects on fibrinolytic activity of corn oil and a fish oil preparation enriched with omega-3-polyunsaturated fatty acids in a long-term study. Curr. Med. Res. Opin. 13:133-139.[Medline]
34. Miller, G. J., Esnouf, M. P., Burgess, A. I., Cooper, J. A. & Mitchell, J. P. (1997) Risk of coronary heart disease and activation of factor XII in middle-aged men. Arterioscler. Thromb. Vasc. Biol. 17:2103-2106.
35. Heller, A. R., Fischer, S., Rossel, T., Geiger, S., Siegert, G., Ragaller, M., Zimmermann, T. & Koch, T. (2002) Impact of (n-3) fatty acid supplemented parenteral nutrition on haemostasis patterns after major abdominal surgery. Br. J. Nutr. 87:S95-S101.
36. Miller, G. J. (1998) Effects of diet composition on coagulation pathways Am. J. Clin. Nutr. 67:542S-545S.
This article has been cited by other articles:
![]() |
M. J Caslake, E. A Miles, B. M Kofler, G. Lietz, P. Curtis, C. K Armah, A. C Kimber, J. P Grew, L. Farrell, J. Stannard, et al. Effect of sex and genotype on cardiovascular biomarker response to fish oils: the FINGEN Study Am. J. Clinical Nutrition, September 1, 2008; 88(3): 618 - 629. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. Sanders, F. Lewis, S. Slaughter, B. A Griffin, M. Griffin, I. Davies, D J. Millward, J. A Cooper, and G. J Miller Effect of varying the ratio of n-6 to n-3 fatty acids by increasing the dietary intake of {alpha}-linolenic acid, eicosapentaenoic and docosahexaenoic acid, or both on fibrinogen and clotting factors VII and XII in persons aged 45-70 y: the OPTILIP Study. Am. J. Clinical Nutrition, September 1, 2006; 84(3): 513 - 522. [Abstract] [Full Text] [PDF] |
||||
![]() |
E Wendland, A Farmer, P Glasziou, and A Neil Effect of {alpha} linolenic acid on cardiovascular risk markers: a systematic review Heart, February 1, 2006; 92(2): 166 - 169. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||