Corn Cockle and Kulesha, Georgy Stepanovich

CORN COCKLE [Agrostemma githago, an annual field plant of the pink family (Caryophyllaceae)], is found as a weed in crops of oats, wheat, and more rarely in rye and other cereals. It blooms at the end of May. It is widely distributed in all countries and in the USSR (in the north and in the south). The corn cockle more often infests spring crops, less often winter crops; it prefers chernozem soil and does not grow on solonchaks; it propagates easily in rainy years. From a sanitary point of view, it is not the plant itself that is of interest, but its seeds (see Vol. X, p. 692, fig. 4), which, when mixed with grains of oats, wheat, etc., can cause symptoms of poisoning in humans and animals. The seeds of the corn cockle, 1.5–2 mm in diameter, have an oval or triangular shape, are black or sometimes brownish in color, and are rough on the surface, which, when viewed under a magnifying glass, has a bumpy appearance. The grain of the corn cockle contains two saponins: agrostemma-saponin and agrostemma-sapotoxin. The corn cockle owes its poisonous properties to the presence of agrostemma-sapotoxin, the amount of which is determined, according to Kobert, to be from 4.1% to 6.6%. Saponins in the corn cockle grain are contained exclusively in the husk and the germ. Like most saponins, they possess sharp hemolytic properties. Corn cockle sapotoxin can be absorbed through an intact mucous membrane and cause general symptoms of poisoning. Humans, horses, sheep, pigs, chickens, pigeons, and guinea pigs are most sensitive to the poison of the corn cockle; rams and rabbits tolerate it more easily. The toxicity of the corn cockle decreases during prolonged storage (by about 20%), as well as during the bread-baking process, during which the corn cockle, depending on the nature and duration of the baking, can lose 50–90% of its toxicity. This explains why no completely reliable cases of poisoning by corn cockle bread have been described in the literature, although the sapotoxin of fresh corn cockle can undoubtedly cause symptoms of gastrointestinal poisoning in humans. Closely related to the question of the toxicity of the corn cockle is the question of the maximum permissible amount of it in flour. The Austrian Food Codex allows a corn cockle content of up to 0.1%. In Germany, up to 0.5% is allowed. In our country, a stricter standard was adopted—0.06%. Recently, the Scientific Medical Council of the People's Commissariat of Health raised this standard to 0.25%. The degree of grain contamination is determined by sorting a specific sample of it and weighing the separated corn cockle seeds on sensitive scales. To clean grain of corn cockle, special machines called cockle separators (trieurs), built on the principle of selective cells, are used. A tentative qualitative detection of corn cockle in flour is performed by microscopic examination of the screenings from the flour (2 g), treated with a mixture of HCl (20 cm³) and potassium chlorate (about 5 g). Under a microscope, the husks of the corn cockle are visible, constructed of serrated circles or ovals, with the teeth overlapping each other. For the quantitative determination of corn cockle in flour, there is the Okolov method, which consists of testing a prepared daily infusion of flour in a physiological solution (25 g of flour + 125 cm³ of physiological solution + 0.3 cm³ of formalin) for the degree of hemolytic properties, namely, the amount of rabbit blood that dissolves in 1 cm³ of this infusion is determined. For this purpose, increasing amounts of washed rabbit erythrocytes in a 1:18 dilution are added to the filtrate from the flour infusion distributed in a row of test tubes. The degree of the hemolytic effect indicates the amount of corn cockle in the flour under investigation. With a content of 0.1% corn cockle, 0.1 cm³ of diluted erythrocytes is hemolyzed; with a content of 0.2%—0.2 cm³, and so on, i.e., the amount of dissolved blood in cubic centimeters will correspond to the amount of corn cockle in the flour in percent. F. Okolov.

KULESHA, Georgy Stepanovich (1866–1930), pathologist and bacteriologist. After graduating from the natural sciences department of the Faculty of Physics and Mathematics of Moscow University and the Medical Faculty of Dorpat (Yuryev) University, Kulesha served from 1896 to 1923 as a prosector at the Maria-Magdalena Hospital (now named after Slutskaya) in Leningrad and, in addition, worked in a number of other laboratories. From 1896 to 1899, he worked under the guidance of the well-known pathologist Uskov at the Institute of Experimental Medicine. From 1911, he was a member of an expedition to study the plague in Manchuria, where he served as a speaker at the International Plague Conference in the city of Mukden. In the same year, he was elected private docent for the course of bacteriology at the St. Petersburg Women's Medical Institute. From 1915 to 1923, he was a professor of pathological anatomy at the Petrograd Institute of Medical Knowledge. From 1923 to 1926, he was the director of the Sevastopol State Bacteriological Institute and a professor at the former Crimean University in Simferopol. From 1926, he served as a professor of pathological anatomy at the Kuban State Medical Institute and director of the Kuban Scientific Research Medical Institute. Kulesha wrote over 50 works devoted to pathological anatomy and bacteriology, mainly of acute infections. Kulesha was the first to point out the existence of hemato-

genic measles pneumonia ("On Pneumonia in Measles," diss., St. Petersburg, 1898) and developed the issue of bile duct involvement in cholera ("On the Pathological Anatomy of Asiatic Cholera," St. Petersburg, 1911). Kulesha is the author of the well-known monograph "Bacillus Carriers and the Fight Against Them" (St. Petersburg, 1914). A number of Kulesha's works concern paratyphoid B (1909), pneumonic plague (1912), influenza (1918), relapsing fever (1922), scarlet fever (1925), and leprosy (1928). He studied in detail the pathological histology of Karachay goiter (together with V. Lauer—"Materials on the Histological Characteristics of Karachay Goiter" in the collection Materials on the Study of Goiter in Karachay, pp. 70–120, Rostov-on-Don, 1929). In addition to scientific and pedagogical activities, Kulesha also conducted significant sanitary organizational work on the waterways of the Mariinsky system in the pre-war years. Recently (1923–29), under Kulesha's leadership, survey work was organized on the spread of tuberculosis among the Tatars in Crimea, and of leprosy and goiter among the indigenous population of the North Caucasus.