causes small amounts of bleeding from the gastric mucosa. ASA-induced occult gastric or gastrointestinal bleeding is usually a local effect resulting from contact of ASA particles, or of the saturated solution of ASA surrounding these particles, with the mucosa.8 Gastroscopic examination has disclosed hemorrhagic erosions immediately adjacent to undissolved ASA tablets.9 To alleviate this undesirable side effect, various forms of buffered, coated or soluble ASA and ASA substitutes have been marketed, but the "plain tablet" dosage form continues to be the most popular. It is therefore imperative that physicians who prescribe ASA or ASA-contaming tablets, and pharmacists who dispense them, give patients the following simple instructions to minimize the occult gastrointestinal bleeding: 1. The tablets may be chewed and swallowed with an adequate amount of water. 2. The tablets may be crushed to a fine powder and the powder taken as a suspension in orange juice. 3. When chewing or crushing is not possible, the tablets should be taken with a large amount of water so as to help dissolve the crystals and prevent the formation of a saturated solution in the stomach. 4. Tablets taken with warm water are better and faster absorbed than those taken with cold water. P.L. MADAN, PH D Associate professor of pharmaceutics St. John's University Jamaica, NY

References 1. Lais. ER, BANWELL JG: Products containing aspirin. N Engi J Med 291: 710, 1974 2. DRESER H: Pharmakologisches uber Aspirin (Acetylsalicylsaure). Pfluegers Arch Gesamte Physiol 76: 306, 1899 3. wOHLGEMUT J: Uber Aspirin (Acetylsalicylsaure). Ther Monatsh (Halbmonatsh) 13: 276, 1899 4. WITrHAUER K: Aspirin, em neues Salicylprepart. Ibid. p 330

men of urine assayed for estrogen and 1 7-ketosteroid content. In each, the ketosteroid value was within the normal range for males, while the estrogen content was within, or close to, the normal range for females. I suggest that in cases of impotence this test may be of value before referral to a psychiatrist. J.C. EDWARDS, SM, S CH Community Health Center

3765 Sherwood Dr. Regina, SK

Sudden death in infants

To the editor: The editorial "Sudden death in infants" (Can Med Assoc J 113: 809, 1975) raised the troublesome question whether this was intended to be a comprehensive article pointing out the more significant theories of sudden infant death syndrome (SIDS), which have been put forward in recent months. Gunther's theory of an immunologic mechanism for SIDS was discussed in 19701 and the evidence supporting this theory was seriously questioned then. Gunther's latest paper2 does not present any new statistical evidence to support her theory, which one would expect to have been obtained in the intervening 5 years. It remains a hypothetical issue, especially in view of several studies that argue against such a theory.34 The important recent advances in the study of neural control of cardiorespiratory function and the physiologic aspects of infant sleep are merely alluded to by the references to the case report of Salk, Grellong and Dietrich.7 Yet these studies8'9 constitute one of the most important advances in SIDS research. I hope this letter will serve to place the current theories of SIDS in a more reasonable perspective. i.E. SMIALEK, MD Project codirector Wayne County S.I.D.S. Center 400 East Lafayette St. Detroit, Ml 48226

5. LANGE HF: Salicylates and gastric hemorrhage. I. Occult bleeding. Gastroenterology

33: 770, 1957 6. Scorr JT, PORTER IH, Lawss SM, et al: Studies on gastrointestinal bleeding caused by corticosteroids, salicylates, and analgesics. Q J Med 30: 167, 1961 7. CUDDSGAN JHP, SWEETLAND C, Cs.ovr DN: Assessment of drug-induced occult bleeding. Rheumatol Phys Med 11: 36, 1971

8. LEONARD JR, LEVY G: Biopharmaceutical aspects of aspirin-induced gastrointestinal blood

loss in man. J Pharm Sci 58: 1277, 1969 9. waiss HJ: Aspirin - dangerous drug? JAMA 229: 1221, 1974

References I. GUNTHER M: in Proceedings of the Sir Samuel Bedson Symposium, Cambridge, Engi, Apr 17, 1970, Dorchester, Engl, Dorset Pr, John Wright & Sons, pp 15-16 2. Idem: The neonate's immunity gap, breast feeding, and cot death. Lancet 1: 441, 1975

3. JOHNSTONE JW, LAWREY HS: Role of infection in cot death. Br Med J 1: 706, 1966

Estrogen and impotence To the editor: During my last 12 months of general practice I have had only three patients who complained of impotence. I had been taught that, in such patients, when no physical abnormalities were to be found, psychiatric referral was indicated. However, for these three I had a 24-hour speci-

4. GOLD E, ADELSON L, GOLDEK G: The role of antibody to cow's milk proteins in the sudden death syndrome. Pediatrics 33: 541

1964 5. COE 31, PETERSON RDA: Sudden unexpected death in infancy and milk sensitivity. J Lab Clin Med 62: 477, 1963 6. VALDES-DAPENA M, FILIPE RP: Immunofluorescent studies in crib deaths: absence of evidence of hypersensitivity to cow's milk. Am J Clin Pathol 56: 412, 1971 7. SALK L, GRELLONO BA, DiamicH J: Sudden

infant death: normal cardiac habituation and poor autonomic control. N Engi .1 Med 291: 219, 1974

8. McGINTY Di, HARPER RM: Sleep physiology and SIDS: animal and human studies, in

498 CMA JOURNAL/MARCH 20, 1976/VOL. 114

Proceedings of The Frances E. Camps national Symposium, Toronto, May 1974, Toronto, Can Foundation for of Infant Deaths, pp 201-29 9. STEINSCHNEIDER A: The concept of apnea as related to SIDS, ibid

Inter15-17, Study sleep

Rubella in Canada

To the editor: In the recent article by R.S. Faulkner and D.A. Gough entitled "Rubella 1974 and its aftermath, congenital rubella syndrome" (Can Med Assoc J 114: 115, 1976) the opening statement that "rubella was made a notifiable disease in Canada in 1969" is misleading. Rubella has been a notifiable disease in Canada since 1924, with the exception of the 10-year period 1959-68, during which only Alberta and Quebec maintained this system.1 Notification was reinstituted in 1969 in all the other provinces except British Columbia, which reintroduced the system in 1971, and Prince Edward Island, which has never recognized rubella as a notifiable disease. The epidemic variability of rubella in terms of interprovincial variation, longterm trends and seasonal variation has not been widely appreciated. FRANK wHITE, CM, M PAUL VARUGHESE, MD, B V SC, M Sc sc Bureau of epidemiology Laboratory Centre for Disease Control Health and welfare Canada Ottawa, ON

Reference 1. Rubella in Canada 1924-1974. Can Dis Wkly Rep 1: 61, 1975

Hazards in laboratories To the editor: From time to time it is devastating to learn that routine laboratory techniques and chemicals impose serious health hazards on both diagnostic and research personnel. Two recent pertinent examples can be cited. The first concerns the hazards from polychlorinated biphenyls in a variety of microscope immersion oils.1 Experiments have shown that these substances are toxic at much lower concentrations than was previously indicated and cause a variety of skin disorders. In addition to the immediate hazard to the user, there is growing concern regarding the ultimate disposal of the immersion oils containing these chemicals. The practice of rinsing microscope slides with solvents and subsequently disposing of the waste solution containing polychlorinated biphenyls in sewage may result in substantial amounts of these substances contaminating potable water supplies and ending up in the food chain. The other example concerns the use of gas chromatographs insulated with