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Carriers Of Disease Organisms: The combination of urethritis and the presence of intracellular gram-negative diplococci in smears of exudate from the urethra are good indications of gonorrhea. Confirmation of the presence of the disease is obtained by culturing the organisms.
Gonorrhea is often asymptomatic in the female, and the diagnosis should be suspected in any female contact of an infected male. Chronic carriers of gonococci are difficult to detect. In the suspected male carrier the secretions of the prostate should be examined as well as those of the urethra.
More recently, emphasis is being placed on pathological considerations in seed testing, and procedures are being developed to test the seeds as hosts and carriers of disease organisms. Progress has been made in the standardization of national and international rules for seed testing in the interest of uniformity and of world trade. The responsibility for seed quality is placed upon the individual or firm which grows and markets the seed, but state and federal governments provide the control through special laboratories for seed testing.
A primitive level of viral engineering was already developing specific disease-causing viruses that can control crop-damaging insects or be used as innocuous competitors of natural pathogens (disease-causing organisms). (See Year in Review: AGRICULTURE.) For higher organisms there was as yet no clue as to how to find a specific gene on an intact chromosome of a given cell and replace it with another. Finding the correct one ten-millionth of the total DNA seemed an implausible aim. Because a wide margin of error would be intolerable, direct viral engineering of the human merited little discussion. |
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