[Morphopathology of myocardial hypoxic-ischemic injuries in newborns at 22-27 weeks' gestation]. / Patomorfologiya gipoksicheski-ishemicheskikh povrezhdenii miokarda u novorozhdennykh 22­27 nedel' gestatsii.

OBJECTIVE: To determine the parameters of myocardial structural injuries developed in chronic intrauterine hypoxia conditions in newborns at 22-27 weeks' gestation. MATERIAL AND METHODS: A battery of morphological techniques, including organometry studies and separate weighing of the heart; 3D histology; morphometry with the determination of the area of cardiomyocyte nuclei, the specific area of the muscular and interstitial components of the right ventricular myocardium; immunohistochemistry with monoclonal antibodies to transforming growth factor ßi (TGF-ßi), cardiac troponin T (cTnT), and transmission electron microscopy, was used to examine heart samples from 30 deceased newborns at 22-27 weeks' gestation who developed in chronic intrauterine hypoxia conditions. A control group consisted of hearts from 20 extremely low body weight (ELBW) newborns, the main cause of whose death was asphyxia caused by the premature detachment of a normally positioned placenta. RESULTS: Analysis of the organometric parameters of heart samples from newborns at 22-27 weeks' gestation, who had experienced chronic intrauterine hypoxia, revealed right ventricular hypertrophy with increases in the area of cardiomyocyte nuclei and in the specific area of the muscle component compared to the control group. Impaired myocardial microcirculation and destructive changes in cardiomyocytes were diagnosed in conjunction with the decreased troponin T and increased TGF-ß1 expressions. Incomplete differentiation of cardiomyocytes and their myofibrillar component was revealed at the myocardial ultrastructural level in ELBW newborns who had experienced chronic intrauterine hypoxia. CONCLUSION: The parameters of myocardial structural rearrangement in ELBW newborns who had experienced chronic intrauterine hypoxia are compensatory right ventricular hypertrophy, microcirculatory disorders, destructive changes in cardiomyocytes, decreased cTnT and increased TGF-ß1 expressions in conjunction with impaired cardiomyocyte differentiation.

[The levels of key nucleolar proteins in the lymphoid cells of healthy individuals and patients with lymphoproliferative diseases].

Immunocytochemical staining with specific antibodies was used to study the expression of three nucleolar proteins (fibrillarin, B23/nucleofozmin, and SURF6), which were involved in pRNA maturation, in the lymphoid cells of healthy individuals and patients with lymphoproliferative diseases and to compare it with the expression of the known proliferation marker Ki-67 protein. The results indicated that fibrillarin was detectable at the comparable level in the lymphoid cells of the patients and in the peripheral blood lymphocytes of the healthy individuals. In one fourth of the patients, the proportion of cells containing B23/nucleofozmin was noticeably higher than that in the lymphocytes of donors; however, there was no great difference in patients with different types of the disease. The number of SURF6-positive cells was directly correlated with that of Ki-67-positive cells. The maximum level (47-67%) of SUR6-positive lymphoid cells was found in splenic lymphosarcomas and mantle cell lymphoma. The findings suggest that SURG6 protein may be of additional diagnostic and prognostic value.

Enhanced sensitivity of nucleoli in human proliferating cells to inhibition of protein synthesis with anisomycin.

We describe the reaction of nuclei in cultured human cells from different tissues to inhibition of total protein synthesis with anisomycin - ribotoxin, which is now considered as a potential antitumor drug. It was shown that nucleoli in sensitive cells demonstrate typical reaction: under the action of the inhibitor, labile nucleolar protein, a component of RNA polymerase I transcription complex (previously called A3 antigen), rapidly migrates from the nucleolus to numerous discrete foci in the nucleoplasm. These changes are specific for translation suppression and are not induced by other influences on the cells. Migration of A3 antigen into the nucleoplasm manifests primarily in cells at the stage of DNA replication and is absent in resting cells. These results suggest that localization of A3 antigen can be a marker of artificial suppression of translation in proliferating human cells in vitro.

Early expression of nucleolar SURF-6 protein in mouse spleen lymphocytes activated for proliferation in vitro.

Using specific antibodies we studied the content of nucleolar SURF-6 protein, which participates in rRNA processing, in mouser spleen lymphocytes activated for proliferation with concanavalin A and compared it with the content of nucleolar nucleophosmin/B23 protein and DNA replication factor PCNA, well-known markers of proliferating cells. Using immunocytochemistry and immunoblotting methods we demonstrate that the concentration of all these proteins increases simultaneously with increasing the proportion of proliferating cells. Unlike nucleophosmin/B23, SURF-6 protein was not revealed in quiescent lymphocyte nucleoli, while the increase of its level in activated lymphocytes preceded elevation of PCNA level. These observations suggest that nucleolar protein SURF-6 can act as a marker of early T lymphocyte activation for proliferation and that it could participate in cell cycle regulation in mammals.

Hygienic classification of pesticides in the Russian Federation.

Hygienic classifications of pesticides used in the Russian Federation are presented. The classifications cover both technical products and preparative forms of pesticides. Four classes of hazards are distinguished: extremely hazardous, hazardous, moderately hazardous, and slightly hazardous. These four classes are used for classifying general toxicity (peroral, skin, inhalation), cumulative, allergic, teratogenic, embryotoxic, reproductive, mutagenic, carcinogenic effects, and the stability in soil. The class of the hazard is determined on the basis of toxicohygienic evaluation of a pesticide, taking into account a limiting criterion of the hazard.