[Effect of low doses of radiation on hematopoiesis in the liver of the human embryo and fetus during the first pregnancy trimester]. / Vliianie malykh doz radiatsii na gemopoéz v pecheni émbriona i ploda cheloveka I trimestra beremennosti.

Percentage and mitotic regimen (mitotic index, mitotic phases, pathological mitosis) of hematopoietic liver cells of the embryos and foetuses (6-12 weeks of development) from females living in normal conditions (Moscow) and in polluted with radionuclides after Chernobyl accident territory of Bryansk region of Russian Federation (towns Novozybkov and Klintsy) are characterized. Moderate but statistically significant (P < 0.05) differences were found in the number of polychromatophilic and oxyphilic normoblasts, basophilic megaloblasts, granulocytes at various developmental stages in the study group compared to the control. No difference was observed in 1992 in the mitotic activity, total number of pathological mitoses and the percentage of binuclear cells. But the spectrum of pathological mitoses, in the contaminated zone, seems to be wider. The mitotic index and the number of cells per 1 mg of organ tissue showed two-fold increase in 1993 in the town of Novozybkov as compared to the control area. The conclusion is made that small radiation doses exert only very slight influence on hematopoiesis in human embryonic and foetal liver of 6-12 weeks of gestation.

[Development of the lymphatic follicles and the differentiation of splenic lymphocytes in the human fetus]. / Razvitie limfaticheskikh follikulov i differentsirovka limfotsitov selezenki u plodov cheloveka.

Spleens of more than 100 human fetuses at the age of 5-34 weeks of development have been studied by means of immunofluorescent methods to identify T- and B-lymphocytes. The spleen lymphatic follicles are detected at the 12th-14th weeks of the embryonal development. Within the same range of time in the mononuclear suspension of the organ T- and B-lymphocytes are defined. The critical period is stated when certain density of lymphocytes and the portion of T- and B-lymphocytes is established in the organ and it is not changed up to the end of embryogenesis. After the 22nd week, the reticular stroma of the lymphatic follicle acquires a complex structure. The following zones can be determined in it: the periarterial where thymus-dependent cells are situated, the zone where thymus-independent cells are situated and the marginal zone surrounding the whole lymphatic follicle.

[Structure of the human spleen and immunomorphologic indices of its lymphocytes during embryogenesis]. / Struktura selezenki cheloveka i immunomorfologicheskie pokazateli ee limfotsitov v émbriogeneze.

The authors studied the development and differentiation of spleen lymphocytes and tissues from 100 human embryos aged 5-34 weeks. T-/E-RFC) and B lymphocytes (IgG plus G cells) were identified by histochemical and immunomorphological methods. The weight and quantitative values of the spleen and lymphocytes are presented. The development of the spleen consists of three periods: 1) an early one (5-8 weeks) when the organ is characterized by a compact arrangement of the mesenchymal cells; 2) 9-11 weeks, when blood deposition function prevails; 3) appearance of lymphopoiesis after 13-14 weeks. Heterogenicity of spleen lymphocytes and the time course of the quantitative changes during embryogenesis are reported. It is concluded that the humans spleen presents a polyfunctional organ even in the embryonal period.

[Immunoglobulin-positive cells of the human spleen and thymus in embryogenesis]. / Issledovanie immunoglobulinpozitivnykh kletok selezenki i timusa cheloveka v embriogeneze.

The percentage and types of fluorescence of immunoglobulin-positive cells were studied in the spleen and thymus from 32 human fetuses aged from 11 to 32 weeks by indirect immunofluorescence. During embryogenesis the number of immunoglobulin-positive cells in the spleen rises from 13 to 33.7%, while in the thymus the percentage of these cells is 0--2 and does not depend on the period of the fetus development. Differentiated estimation of immunoglobulin-positive cells was performed for the first time during embryogenesis from the types of fluorescence. Thymocytes have solitary points of fluorescence on the surface. Lymphocytes with solitary and then with multiple points covering all the surface and at last with "caps" of fluorescence appear in the spleen during the period of the development. The different density of immunoglobulin receptors on the surface reflects the level of lymphocyte differentiation.

[Properties and kinetics of a population of B-lymphocytes during rat ontogenesis]. / Svoistva i kinetika populiatsii B-limfotsitov v ontogeneze krysy.

Cells bearing surface immunoglobulins (Ig+-cells) detected by the indirect immunofluorescent method and cells forming rosettes (RFC) with sheep erythrocytes coated with antibody and complement (EAC rosettes) were found in the liver and the spleen on the 15th and the 20th days of prenatal life of rats. The percentage of Ig+-cells and RFC in the liver was high and remained unchanged and at about the same level during the whole postnatal life. The spleen and the bone marrow displayed an increase of the Ig+-cells and RFC increased throughout the 1st month of postnatal life with the maximum at the 30th day after birth; a sharp decrease occurred in old animals. In the thymus the Ig+-cells and the RFC were either absent or present in very small amounts only at some periods of study. Ig+-cells with "capping" were discovered in the spleen and bone marrow on the 5th--10th days of postnatal life; their count increased considerably in 30-day and adult rats. Such cells were absent in the lymphoid tissues of old 40-month rats.

[Human, guinea pig and rat lympocyte rosette formation with spermatozoids]. / Obrazovaine limfotsitami cheloveka, morskikh svinok i krys rozetok so spermatozoidami

In the thymus, spleen and bone marrow of adult guinea pigs, 14--30-week human fetuses, and the peripheral blood of sterile men there were found cells capable of forming the rosettes with homo- or heterologous spermatozoa (RFC). Development of autoimmune orchitis after the trauma of the rat testis or after the guinea pig immunization with the testicular homogenate mixed with complete Freund's adjuvant caused the appearance of RFC with spermatozoa in the thymus and the spleen of rats, and an increase of their number in the lymphoid organs of guinea pigs. Such treatment did not influence the quantity of sheep-cell rosettes in the lymphoid organs of rats and guinea pigs. A possibility of using the detected capacity of animal and human lymphocytes to form spontaneous and immune rosettes with the spermatozoa to test the degree of lympocyte differentiation and their sensitisation to the spermatozoa antigens after the spermatogenesis distrubances of the autoimmune nature is discussed.