Free Shipping on All Orders $75 Or More! Ends January 31st.

Your Trusted Brand for Over 35 Years

Life Extension Magazine

<< Back to October 2005

Just Say No to X-Rays!

October 2005

By William Faloon


1. Available at: practice/mvp/default.htm. Accessed July 29, 2005.

2. Available at: mag2003/feb2003_awsi_01.html. Accessed July 29, 2005.

3. Available at: mag2004/mar2004_awsi_death_01.htm. Accessed July 29, 2005.

4. Sutherland BM, Bennett PV, Sidorkina O, Laval J. Clustered DNA damages induced in isolated DNA and in human cells by low doses of ionizing radiation. Proc Natl Acad Sci USA. 2000 Jan 4;97(1):103-8.

5. Boudaiffa B, Cloutier P, Hunting D, Huels MA, Sanche L. Resonant formation of DNA strand breaks by low-energy (3 to 20 eV) electrons. Science. 2000 Mar 3;287(5458):1658-60.

6. Haber D. Roads leading to breast cancer. N Engl J Med. 2000 Nov 23;343(21):1566-8.

7. Available at: mag2001/nov2001_report_radiation_01.html. Accessed July 29, 2005.

8. Boice JD, Jr., Monson RR. Breast cancer in women after repeated fluoroscopic examinations of the chest. J Natl Cancer Inst. 1977 Sep;59(3):823-32.

9. Gridley DS, Andres ML, Slater JM. Enhancement of prostate cancer xenograft growth with whole-body radiation and vascular endothelial growth factor. Anticancer Res. 1997 Mar;17(2A):923-8.

10. Available at: Accessed July 29, 2005.

11. Available at: Accessed July 29, 2005.

12. Available at: Accessed July 29, 2005.

13. Available at: id/8389834/. Accessed July 29, 2005.

14. Available at: Accessed July 29, 2005.

15. Available at: Accessed July 29, 2005.

16. Available at: 030909156X/html/10.html. Accessed July 29, 2005.

17. Available at: Accessed July 29, 2005.

18. Available at: Accessed July 29, 2005.

19. Available at: Accessed July 29, 2005.

20. Sheehan JF. Foam cell plaques in the intima of irradiated small arteries. Arch Path. 1944;379:297-08.

21. Cheng SW, Ting AC, Wu LL. Ultrasonic analysis of plaque characteristics and intimal-medial thickness in radiation-induced atherosclerotic carotid arteries. Eur J Vasc Endovasc Surg. 2002 Dec;24(6):499-504.

22. Dossing M, Rasmussen S, Fischer-Hansen B, Walbom-Jorgensen S. Radiation-induced lesions of the aorta. Br Med J. 1977 Apr 9;1(6066):973.

23. Tribble DL, Barcellos-Hoff MH, Chu BM, Gong EL. Ionizing radiation accelerates aortic lesion formation in fat-fed mice via SOD-inhibitable processes. Arterioscler Thromb Vasc Biol. 1999 Jun;19(6):1387-92.

24. Notaristefano S, Giombolini C, Santucci S, et al. Radiation-induced ostial stenosis of the coronary artery as a cause of acute coronary syndromes: a novel mechanism of thrombus formation? Ital Heart J. 2003 May;4(5):341-4.

25. Takewa Y, Kawata T, Yoshida Y, Kawachi K, Kitamura S. Radiation-induced coronary ostial stenosis, a case of redo coronary bypass for the restenosis following patch angioplasty. Nippon Kyobu Geka Gakkai Zasshi. 1996 Feb;44(2):220-5.

26. Verheij M, Dewit LG, Boomgaard MN, Brinkman HJ, van Mourik JA. Ionizing radiation enhances platelet adhesion to the extracellular matrix of human endothelial cells by an increase in the release of von Willebrand factor. Radiat Res. 1994 Feb;137(2):202-7.

27. Hicks GL, Jr. Coronary artery operation in radiation-associated atherosclerosis: long-term follow-up. Ann Thorac Surg. 1992 Apr;53(4):670-4.

28. Elkeles A. Metabolic behavior of alpha-ray activity in large human arteries: relationship to atherosclerosis. J Am Geriatr Soc. 1977 Apr;25(4):179-85.

29. Elkeles A. Alpha-ray activity in the large human arteries. Nature. 1969 Feb 15;221(181):662-4.

30. Available at: skimit.cgi?isbn=0309040493&chap=57-76. Accessed July 29, 2005.

31. Available at: major/dvs/mortdata.htm. Accessed July 29, 2005.

32. Available at: sec03/ch033/ch033a.html. Accessed July 29, 2005.

33. Available at: Accessed July 29, 2005.

34. MacDonald-Wicks L, Gibson LZ, Godfrey DM, et al. Oxidised LDL in newly diagnosed type 2 diabetes mellitus and impaired glucose tolerance. Asia Pac J Clin Nutr. 2004;13(Suppl):S65.

35. Ceriello A. Impaired glucose tolerance and cardiovascular disease: the possible role of post-prandial hyperglycemia. Am Heart J. 2004 May;147(5):803-7.

36. Bots ML, Launer LJ, Lindemans J, Hofman A, Grobbee DE. Homocysteine, atherosclerosis and prevalent cardiovascular disease in the elderly: The Rotterdam Study. J Intern Med. 1997 Oct;242(4):339-47.

37. Folsom AR, Nieto FJ, McGovern PG, et al. Prospective study of coronary heart disease incidence in relation to fasting total homocysteine, related genetic polymorphisms, and B vitamins: the Atherosclerosis Risk in Communities (ARIC) study. Circulation. 1998 Jul 21;98(3):204-10.

38. Montalescot G, Ankri A, Chadefaux-Vekemans B, et al. Plasma homocysteine and the extent of atherosclerosis in patients with coronary artery disease. Int J Cardiol. 1997 Aug 8;60(3):295-300.

39. Stampfer MJ, Malinow MR, Willett WC, et al. A prospective study of plasma homocyst(e)ine and risk of myocardial infarction in US physicians. JAMA. 1992 Aug 19;268(7):877-81.

40. Verhoef P, Stampfer MJ, Buring JE, et al. Homocysteine metabolism and risk of myocardial infarction: relation with vitamins B6, B12, and folate. Am J Epidemiol. 1996 May 1;143(9):845-59.

41. Robinson K, Mayer EL, Miller DP, et al. Hyperhomocysteinemia and low pyridoxal phosphate. Common and independent reversible risk factors for coronary artery disease. Circulation. 1995 Nov 15;92(10):2825-30.

42. Arnesen E, Refsum H, Bonaa KH, et al. Serum total homocysteine and coronary heart disease. Int J Epidemiol. 1995 Aug;24(4):704-9.

43. Aronow WS, Ahn C. Association between plasma homocysteine and coronary artery disease in older persons. Am J Cardiol. 1997 Nov 1;80(9):1216-8.

44. Berwanger CS, Jeremy JY, Stansby G. Homocysteine and vascular disease. Br J Surg. 1995 Jun;82(6):726-31.

45. Bostom AG, Rosenberg IH, Silbershatz H, et al. Nonfasting plasma total homocysteine levels and stroke incidence in elderly persons: the Framingham Study. Ann Intern Med. 1999 Sep 7;131(5):352-5.

46. Ridker PM, Rifai N, Rose L, Buring JE, Cook NR. Comparison of C-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events. N Engl J Med. 2002 Nov 14;347(20):1557-65.

47. Kanani PM, Sinkey CA, Browning RL, et al. Role of oxidant stress in endothelial dysfunction produced by experimental hyperhomocyst(e)inemia in humans. Circulation. 1999 Sep 14;100(11):1161-8.

48. Van der Meide PH, Schellekens H. Cytokines and the immune response. Biotherapy. 1996;8(3-4):243-9.

49. No author. Role of inflammatory and hemostatic mediators in preclinical endothelial dysfunction: Relevance to high-risk patients with hypertension. JACC. 2002 Mar 6;39(5):209A.

50. Tentolouris C, Tousoulis D, Antoniades C, et al. Endothelial function and proinflammatory cytokines in patients with ischemic heart disease and dilated cardiomyopathy. Int J Cardiol. 2004 Apr;94(2-3):301-5.

51. Ikonomidis I, Lekakis J, Vamvakou G, Andreotti F, Nihoyannopoulos P. Cigarette smoking is associated with increased circulating proinflammatory and procoagulant markers in patients with chronic coronary artery disease: effects of aspirin treatment. Am Heart J. 2005 May;149(5):832-9.

52. Esen AM, Barutcu I, Acar M, et al. Effect of smoking on endothelial function and wall thickness of brachial artery. Circ J. 2004 Dec;68(12):1123-6.

53. Ambrose JA, Barua RS. The pathophysiology of cigarette smoking and cardiovascular disease: an update. J Am Coll Cardiol. 2004 May 19;43(10):1731-7.

54. Poreba R, Skoczynska A, Derkacz A. Effect of tobacco smoking on endothelial function in patients with coronary arteriosclerosis. Pol Arch Med Wewn. 2004 Jan;111(1):27-36.

55. Puranik R, Celermajer DS. Smoking and endothelial function. Prog Cardiovasc Dis. 2003 May;45(6):443-58.

56. Vlassara H, Cai W, Crandall J, et al. Inflammatory mediators are induced by dietary glycotoxins, a major risk factor for diabetic angiopathy. Proc Natl Acad Sci USA. 2002 Nov 26;99(24):15596-601.

57. Cuevas AM, Germain AM. Diet and endothelial function. Biol Res. 2004;37(2):225-30.

58. Chang HJ, Chung J, Choi SY, et al. Endothelial dysfunction in patients with exaggerated blood pressure response during treadmill test. Clin Cardiol. 2004 Jul;27(7):421-5.

59. Tu L, Wei W, Liu X, Deng Y, Yu S. Endothelial function and carotid artery wall thickening in patients with early essential hypertension. J Tongji Med Univ. 1999;19(4):288-90, 303.

60. Rodriguez-Porcel M, Lerman LO, Herrmann J, et al. Hypercholesterolemia and hypertension have synergistic deleterious effects on coronary endothelial function. Arterioscler Thromb Vasc Biol. 2003 May 1;23(5):885-91.

61. Higashi Y, Yoshizumi M. Exercise and endothelial function: role of endothelium-derived nitric oxide and oxidative stress in healthy subjects and hypertensive patients. Pharmacol Ther. 2004 Apr;102(1):87-96.

62. Fan J, Watanabe T. Inflammatory reactions in the pathogenesis of atherosclerosis. J Atheroscler Thromb. 2003;10(2):63-71.

63. Li JJ, Chen JL. Inflammation may be a bridge connecting hypertension and atherosclerosis. Med Hypotheses. 2005;64(5):925-9.

64. Johnson LK, Longenecker JP, Fajardo LF. Differential radiation response of cultured endothelial cells and smooth myocytes. Anal Quant Cytol. 1982 Sep;4(3):188-98.

65. Maresca G, Di Blasio A, Marchioli R, Di Minno G. Measuring plasma fibrinogen to predict stroke and myocardial infarction: an update. Arterioscler Thromb Vasc Biol. 1999 Jun;19(6):1368-77.

66. Acevedo M, Foody JM, Pearce GL, Sprecher DL. Fibrinogen: associations with cardiovascular events in an outpatient clinic. Am Heart J. 2002 Feb;143(2):277-82.

67. Ridker PM, Stampfer MJ, Rifai N. Novel risk factors for systemic atherosclerosis: a comparison of C-reactive protein, fibrinogen, homocysteine, lipoprotein(a), and standard cholesterol screening as predictors of peripheral arterial disease. JAMA. 2001 May 16;285(19):2481-5.

68. Lindahl B, Toss H, Siegbahn A, Venge P, Wallentin L. Markers of myocardial damage and inflammation in relation to long-term mortality in unstable coronary artery disease. FRISC Study Group. Fragmin during Instability in Coronary Artery Disease. N Engl J Med. 2000 Oct 19;343(16):1139-47.

69. Ridker PM, Hennekens CH, Buring JE, Rifai N. C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. N Engl J Med. 2000 Mar 23;342(12):836-43.

70. Kuller LH, Tracy RP, Shaten J, Meilahn EN. Relation of C-reactive protein and coronary heart disease in the MRFIT nested case-control study. Multiple Risk Factor Intervention Trial. Am J Epidemiol. 1996 Sep 15;144(6):537-47.

71. Mendall MA, Strachan DP, Butland BK, et al. C-reactive protein: relation to total mortality, cardiovascular mortality and cardiovascular risk factors in men. Eur Heart J. 2000 Oct;21(19):1584-90.

72. Pasceri V, Willerson JT, Yeh ET. Direct proinflammatory effect of C-reactive protein on human endothelial cells. Circulation. 2000 Oct 31;102(18):2165-8.

73. Ridker PM, Buring JE, Shih J, Matias M, Hennekens CH. Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women. Circulation. 1998 Aug 25;98(8):731-3.

74. Auer J, Berent R, Lassnig E, Eber B. C-reactive protein and coronary artery disease. Jpn Heart J. 2002 Nov;43(6):607-19.

75. Maxwell SR. Coronary artery disease—free radical damage, antioxidant protection and the role of homocysteine. Basic Res Cardiol. 2000;95 Suppl 1:I65-71.

76. Johansen JS, Harris AK, Rychly DJ, Ergul A. Oxidative stress and the use of antioxidants in diabetes: linking basic science to clinical practice. Cardiovasc Diabetol. 2005 Apr 29;4(1):5.

77. Schulz E, Anter E, Keaney JF Jr. Oxidative stress, antioxidants, and endothelial function. Curr Med Chem. 2004 May;11(9):1093-104.

78. Basta G, Lazzerini G, Massaro M, et al. Advanced glycation end products activate endothelium through signal-transduction receptor RAGE: a mechanism for amplification of inflammatory responses. Circulation. 2002 Feb 19;105(7):816-22.

79. Baynes JW. From life to death—the struggle between chemistry and biology during aging: the Maillard reaction as an amplifier of genomic damage. Biogerontology. 2000;1(3):235-46.

80. Lebovitz HE. Effect of the postprandial state on nontraditional risk factors. Am J Cardiol. 2001 Sep 20;88(6A):20H-5H.

81. Sasso FC, Carbonara O, Nasti R, et al. Glucose metabolism and coronary heart disease in patients with normal glucose tolerance. JAMA. 2004 Apr 21;291(15):1857-63.

82. Woo KS, Chook P, Chan LL, et al. Long-term improvement in homocysteine levels and arterial endothelial function after 1-year folic acid supplementation. Am J Med. 2002 May;112(7):535-9.

83. Doshi S, McDowell I, Moat S, Lewis M, Goodfellow J. Folate improves endothelial function in patients with coronary heart disease. Clin Chem Lab Med. 2003 Nov;41(11):1505-12.

84. Doshi SN, McDowell IF, Moat SJ, et al. Folic acid improves endothelial function in coronary artery disease via mechanisms largely independent of homocysteine lowering. Circulation. 2002 Jan 1;105(1):22-6.

85. Paradisi G, Cucinelli F, Mele MC, et al. Endothelial function in post-menopausal women: effect of folic acid supplementation. Hum Reprod. 2004 Apr;19(4):1031-5.

86. Pena AS, Wiltshire E, Gent R, Hirte C, Couper J. Folic acid improves endothelial function in children and adolescents with type 1 diabetes. J Pediatr. 2004 Apr;144(4):500-4.

87. Moat SJ, Lang D, McDowell IF, et al. Folate, homocysteine, endothelial function and cardiovascular disease. J Nutr Biochem. 2004 Feb;15(2):64-79.

88. Hernandez-Diaz S, Martinez-Losa E, Fernandez-Jarne E, Serrano-Martinez M, Martinez-Gonzalez MA. Dietary folate and the risk of nonfatal myocardial infarction. Epidemiology. 2002 Nov;13(6):700-6.

89. Czeizel E, Kalina A. Public health control of hyperhomocysteinemia and its consequences. Orv Hetil. 2003 Oct 5;144(40):1981-9.

90. Gokce N, Keaney JF, Jr., Frei B, et al. Long-term ascorbic acid administration reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Circulation. 1999 Jun 29;99(25):3234-40.

91. Jeserich M, Schindler T, Olschewski M, et al. Vitamin C improves endothelial function of epicardial coronary arteries in patients with hypercholesterolaemia or essential hypertension—assessed by cold pressor testing. Eur Heart J. 1999 Nov;20(22):1676-80.

92. Deng YB, Xiang HJ, Chang Q, Li CL. Evaluation by high-resolution ultrasonography of endothelial function in brachial artery after Kawasaki disease and the effects of intravenous administration of vitamin C. Circ J. 2002 Oct;66(10):908-12.

93. Ling L, Zhao SP, Gao M, et al. Vitamin C preserves endothelial function in patients with coronary heart disease after a high-fat meal. Clin Cardiol. 2002 May;25(5):219-24.

94. Singh N, Graves J, Taylor PD, MacAllister RJ, Singer DR. Effects of a ‘healthy’ diet and of acute and long-term vitamin C on vascular function in healthy older subjects. Cardiovasc Res. 2002 Oct;56(1):118-25.

95. Mostafa S el-D, Garner DD, Garrett L, et al. Beneficial effects of vitamin C on risk factors of cardiovascular diseases. J Egypt Public Health Assoc. 1989;64(1-2):123-33.

96. Chin JP, Dart AM. HBPRCA Astra Award. Therapeutic restoration of endothelial function in hypercholesterolaemic subjects: effect of fish oils. Clin Exp Pharmacol Physiol. 1994 Oct;21(10):749-55.

97. Goodfellow J, Bellamy MF, Ramsey MW, Jones CJ, Lewis MJ. Dietary supplementation with marine omega-3 fatty acids improve systemic large artery endothelial function in subjects with hypercholesterolemia. J Am Coll Cardiol. 2000 Feb;35(2):265-70.

98. Flaten H, Hostmark AT, Kierulf P, et al. Fish-oil concentrate: effects on variables related to cardiovascular disease. Am J Clin Nutr. 1990 Aug;52(2):300-6.

99. von Schacky C, Angerer P, Kothny W, Theisen K, Mudra H. The effect of dietary omega-3 fatty acids on coronary atherosclerosis. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 1999 Apr 6;130(7):554-62.

100. Daviglus ML, Stamler J, Orencia AJ, et al. Fish consumption and the 30-year risk of fatal myocardial infarction. N Engl J Med. 1997 Apr 10;336(15):1046-53.

101. Kremer JM. n-3 fatty acid supplements in rheumatoid arthritis. Am J Clin Nutr. 2000 Jan;71(1 Suppl):349S-51S.

102. James MJ, Gibson RA, Cleland LG. Dietary polyunsaturated fatty acids and inflammatory mediator production. Am J Clin Nutr. 2000 Jan;71(1 Suppl):343S-8S.

103. De Caterina R, Massaro M. Effects of diet and of dietary components on endothelial leukocyte adhesion molecules. Curr Atheroscler Rep. 1999 Nov;1(3):188-95.

104. Yaqoob P, Calder PC. N-3 polyunsaturated fatty acids and inflammation in the arterial wall. Eur J Med Res. 2003 Aug 20;8(8):337-54.

105. German JB, Lokesh B, Kinsella JE. The effect of dietary fish oils on eicosanoid biosynthesis in peritoneal macrophages is influenced by both dietary N-6 polyunsaturated fats and total dietary fat. Prostaglandins Leukot Essent Fatty Acids. 1988 Oct;34(1):37-45.

106. De Caterina R, Spiecker M, Solaini G, et al. The inhibition of endothelial activation by unsaturated fatty acids. Lipids. 1999;34 SupplS191-4.

107. Khalfoun B, Thibault F, Watier H, Bardos P, Lebranchu Y. Docosahexaenoic and eicosapentaenoic acids inhibit in vitro human endothelial cell production of interleukin-6. Adv Exp Med Biol. 1997;400B:589-97.

108. Das UN. Beneficial effect(s) of n-3 fatty acids in cardiovascular diseases: but, why and how? Prostaglandins Leukot Essent Fatty Acids. 2000 Dec;63(6):351-62.

109. Smith AR, Hagen TM. Vascular endothelial dysfunction in aging: loss of Akt-dependent endothelial nitric oxide synthase phosphorylation and partial restoration by (R)-alpha-lipoic acid. Biochem Soc Trans. 2003 Dec;31(Pt 6):1447-9.

110. Jones W, Li X, Qu ZC, et al. Uptake, recycling, and antioxidant actions of alpha-lipoic acid in endothelial cells. Free Radic Biol Med. 2002 Jul 1;33(1):83-93.

111. Zhang WJ, Frei B. Alpha-lipoic acid inhibits TNF-alpha-induced NF-kappaB activation and adhesion molecule expression in human aortic endothelial cells. FASEB J. 2001 Nov;15(13):2423-32.

112. Morcos M, Borcea V, Isermann B, et al. Effect of alpha-lipoic acid on the progression of endothelial cell damage and albuminuria in patients with diabetes mellitus: an exploratory study. Diabetes Res Clin Pract. 2001 Jun;52(3):175-83.

113. Kunt T, Forst T, Wilhelm A, et al. Alpha-lipoic acid reduces expression of vascular cell adhesion molecule-1 and endothelial adhesion of human monocytes after stimulation with advanced glycation end products. Clin Sci (Lond). 1999 Jan;96(1):75-82.

114. Gao TL and Huang YZ. Effects of lipoic acid on reperfusion induced arrhythmias and myocardiac action potential alterations induced by free radical generating system. Sheng Li Xue Bao. 1991 Apr;43(2):149-55.

115. Coombes JS, Powers SK, Hamilton KL, et al. Improved cardiac performance after ischemia in aged rats supplemented with vitamin E and alpha-lipoic acid. Am J Physiol Regul Integr Comp Physiol. 2000 Dec;279(6):R2149-55.

116. Vodoevich VP. Effect of lipoic acid, biotin and pyridoxine on blood content of saturated and unsaturated fatty acids in ischemic heart disease and hypertension. Vopr Pitan. 1983 Sep;(5):14-16.

117. Shih JC. Atherosclerosis in Japanese quail and the effect of lipoic acid. Fed Proc. 1983 May 15;42(8):2494-7.

118. Moat SJ, Lang D, McDowell IF, et al. Folate, homocysteine, endothelial function and cardiovascular disease. J Nutr Biochem. 2004 Feb;15(2):64-79.

119. Ness AR, Powles JW, Khaw KT. Vitamin C and cardiovascular disease: a systematic review. J Cardiovasc Risk. 1996 Dec;3(6):513-21.

120. Wilkinson IB, Megson IL, MacCallum H, et al. Oral vitamin C reduces arterial stiffness and platelet aggregation in humans. J Cardiovasc Pharmacol. 1999 Nov;34(5):690-3.

121. FTC reaches record price-fixing settlement to settle charges of price-fixing in generic drug market [press release]. Washington, DC: Federal Trade Commission; November 29, 2000.

122.Yam D, Bott-Kanner G, Genin I, Shinitzky M, Klainman E. The effect of omega-3 fatty acids on risk factors for cardiovascular diseases. Harefuah. 2001 Dec;140(12):1156-8, 1230.

123. Available at: cvh/hp2010/objectives.htm. Accessed July 29, 2005.

124. Esposito K, Marfella R, Ciotola M, et al. Effect of a mediterranean-style diet on endothelial dysfunction and markers of vascular inflammation in the metabolic syndrome: a randomized trial. JAMA. 2004 Sep 22;292(12):1440-6.

125. Chade AR, Lerman A, Lerman LO. Kidney in early atherosclerosis. Hypertension. 2005 Jun;45(6):1042-49.

126. Available at: news2004-mchi/2334.html. Accessed July 29, 2005.

127. Available at: print/view/1,1560,RA_489_learn,00.html. Accessed July 29, 2005.

128. Maas R, Schwedhelm E, Albsmeier J, Boger RH. The pathophysiology of erectile dysfunction related to endothelial dysfunction and mediators of vascular function. Vasc Med. 2002 Aug;7(3):213-25.

129. Feldman HA, Johannes CB, Derby CA, et al. Erectile dysfunction and coronary risk factors: prospective results from the Massachusetts male aging study. Prev Med. 2000 Apr;30(4):328-38.

130. Fung MM, Bettencourt R, Barrett-Connor E. Heart disease risk factors predict erectile dysfunction 25 years later: the Rancho Bernardo Study. J Am Coll Cardiol. 2004 Apr 21;43(8):1405-11.

131. Bivalacqua TJ, Usta MF, Champion HC, Kadowitz PJ, Hellstrom WJ. Endothelial dysfunction in erectile dysfunction: role of the endothelium in erectile physiology and disease. J Androl. 2003 Nov;24(6 Suppl):S17-S37.