Konchalovsky and Conjugation

Maxim Petrovich Konchalovsky (born 1875), a prominent therapist, director of the faculty therapeutic clinic of the 1st Moscow State University; in 1899 he graduated from the medical faculty of Moscow University. K. worked for 18 years in the faculty therapeutic clinic under the guidance of V. D. Shervinsky and L. E. Golubinin. In 1912 he became a privat-docent, in 1918 he was elected professor of the hospital therapeutic clinic of the Higher Women's Courses, now the 2nd Moscow State University; from 1927 to 1929 K. served as dean of the medical faculty of the 2nd Moscow State University. From 1929 K. was director of the faculty therapeutic clinic of the 1st Moscow State University. From 1919 he served as deputy chairman of the Moscow Therapeutic Society, and since 1923 he has served as chairman of this same society. K. was a founder of the congresses of Russian therapists and serves as deputy chairman of the Society of Therapists of the USSR; he took an active part in the reform of medical education and in the organization of new medical institutions of the People's Commissariat of Health and the Moscow Health Department. K. is a member of the Medical Methodological Commission of the Main Administration of Professional Education. Since 1925 he has been a member of the State Academic Council. K. is a member of the Scientific Medical Council of the People's Commissariat of Health of the RSFSR, chairman of the Central Scientific Resort Commission, founder and honorary member of the Scientific Resort Society, chairman of the Committee for the Study of Rheumatism, deputy director of the State Scientific Institute named after A. A. Bogdanov, and a consultant to the Institute for the Study of Occupational Diseases named after V. A. Obukh. In 1927 and 1928 he was a member of the Moscow Soviet, elected from the 2nd Moscow State University; he is a member of the International Balneological Society and a representative of the USSR in the International League Against Rheumatism. In 1922 K. founded the journal "Therapeutic Archive" and serves as its editor-in-chief, co-editor of the "Great Medical Encyclopedia," the publication "Library of the Practical Physician," and others. K. has published about 60 printed works in total, of which the following should be noted: "Gastric Achylia" (dissertation, Moscow, 1911); "Diabetes, its Diagnosis and Treatment" (together with N. Zolotareva, Moscow-Leningrad, 1928); "Clinic of Lung Cancer" (Moscow-Leningrad, 1930); "On Pulmonary Suppurations and Indications for their Surgical Treatment" (Program of reports of the VII Congress of Therapists); "Functional Diagnostics of the Liver" (VIII Congress); "Clinical Characteristics of the Hepato-Lienal Syndrome" (X Congress); "Treatment of Patients with Basedow's Disease" (X Congress) and a number of others.

CONJUGATION (from Latin conjugatio - connection), a sexual process in infusoria; it consists of a temporary, close contact between two individuals, which at this time exchange parts of their nuclei. The scheme of C. (Figs. 1 and 2) is based on the existence in infusoria

Data: a-d-conj

[Fragment]

jugation; h-j - post

Figure 2. Conjugation in... conjugation period

Paramaec. caudatum (1- period; reconstruction

7); 8 - 11 - post-conjugation of the macronucleus.

conjugation period. [The text continues:] ...of a dimorphic nuclear apparatus, consisting of a macro- and a micronucleus. In the simplest case with 1 macro- and 1 micronucleus, for example in the slipper animalcule (Paramaecium caudatum), the scheme of C. is as follows. Two infusoria-conjugants align so that a protoplasmic bridge forms between their cytostomes. At this time, their macronuclei disintegrate and degenerate, and the micronuclei divide twice. Of the 4 daughter elements of the micronucleus thus formed in each conjugant, 3 degenerate, and the 4th divides once more in each conjugant, with one half turning into a stationary micronucleus and remaining in the same individual, and the second—the migratory micronucleus—passing to the partner and fusing with the stationary part of its micronucleus, which corresponds to the process of fertilization. After this, the conjugants separate. Thus, at the beginning of the post-conjugation period, each conjugant does not yet have a macronucleus, but possesses only 1 micronucleus. The latter divides, with one of the products of its division being reconstructed into a new macronucleus, and the other forming a micronucleus. Thus, during C., the destruction of the old macronuclei, the mutual fertilization of two individuals, and the reconstruction of the macronucleus occur. In connection with this, the biological significance of C. boils down to two moments: reorganization of the macronucleus and fertilization. C. usually occurs after a series of vegetative divisions, when, as a result of a trophic period under the influence of toxic metabolic products accumulated in the surrounding environment, the infusoria pass into a state of depression, usually accompanied by hypertrophy of the macronucleus. The only way out of the state of depression is the reconstruction of the macronucleus. In connection with this, after C., the normal vegetative existence of the infusoria and its asexual reproduction are restored. This connection was first noted by Maupas (1888), who introduced the concept of rejuvenation by nuclear fusion ("rajeunissement caryogamique"). Since the reconstruction of the macronucleus is carried out by endomixis (see), C. may not occur at all. The experiments of American protistologists (Calkins, Woodruff) are based on this, as they managed to maintain the asexual reproduction of infusoria for over 10,000 generations without allowing C. Thus, from the point of view of vegetative life, the periodic reconstruction of the macronucleus is more important for the infusoria than the fertilization of the micronucleus. The latter has only genetic significance. G. Epstein. Chromosome conjugation—the paired connection of homologous chromosomes, occurring during the preparation of germ cells for the two final divisions performed by them before final maturation. One of these divisions is the reductional one, in which the chromosomes do not split, as in all others, but the members of the previously conjugated pair move to the poles of the daughter cells. C. thus ensures the uniform distribution of paired chromosomes among the daughter nuclei and makes it possible for chromosomes of paternal and maternal origin to combine in them according to the laws of chance. Besides this, during C., an exchange of parts can take place between homologous chromosomes. All this makes C. one of the most important moments of the complex processes of germ cell maturation. Lit.: Doflein F., Lehrbuch der Protozoenkunde, Vol. 1 p. 271, Jena, 1927 (lit.).