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Using immunofluorescence with specific antibodies, we analyzed DNA hydroxymethylation in uncultured cells from 25 human uterine leiomyomas considering the menstrual cycle phase during surgery and the presence of MED12 gene mutations. It was found that each tumor node had specific DNA hydroxymethylation level that did not depend on the presence of mutations in MED12 gene, but depended on the phase of menstrual cycle. The degree of DNA hydroxymethylation was significantly lower in cells of leiomyomas excised during the luteal phase compared to the follicular phase (p=0.0431). Hormonal status changing at various phases of menstrual cycle is a factor affecting DNA hydroxymethylation in leiomyoma cells.

We studied the effect of peptide AEDG on telomere length and mitotic index of PHA-stimulated blood lymphocytes from young (18-22 years, N=5) and middle-aged (49-54 years, N=6) men. In the younger age group, no significant changes in the mitotic index were detected, while in the middle-aged group, a decrease in this parameter was found in one case. The relative length of telomeric regions of metaphase chromosomes was evaluated by in situ fluorescence hybridization with DNA probes specific to telomeres. After incubation with peptide AEDG, significant changes in the relative telomere length were found in 7 of 11 individuals (3 cases in the younger age group and 4 cases in the middle age group). Significant increase in telomere length after exposure to peptide AEDG was revealed in 5 cases, including two individuals of the younger age group (by 41 and 55%) and three individuals of the middle age group (by 156, 18, and 76%). In one individual of the younger age group and in one of the middle-age group, a significant decrease in telomere length (by 37 and 15%, respectively) was found. A tendency to normalization of telomere lengths was noted: this parameter increased in individuals with initially lower telomere length relative to the group mean value and decreased in individuals with initially longer telomeres compared to the mean length in the group.

A novel method of ground simulation in humans of physiological effects induced by the stay on the surface of celestial bodies with hypogravity was developed and successfully tested. This method is based on the change of gravity force angle, which decreases the gravitational component of the blood hydrostatic pressure characteristic of human vertical posture on the Earth and the load-weight onto the locomotor apparatus to the lower values expected at celestial bodies with hypogravity. The methodological requirements for ground simulation of the physiological effects of lunar gravity on human body are specified and substantiated by theoretical calculations. The experimental study revealed redistribution of liquid media in the human organism, functional changes in the cardiorespiratory system, and a decrease in the load-weight applied to the locomotor apparatus.

Analysis of ultrastructural changes in diaphragm muscle and synaptic apparatus after 7- and 14-day biosatellite spaceflight showed destructive and atrophic changes that developed starting from in the early terms of exposure. Structural alterations of different severity were revealed in all elements of the muscle (muscle fibers, neuromuscular junctions, intramuscular nerves, and blood vessels) and were paralleled by activation of regeneration processes.

Rat hepatocytes were examined under electron microscope at early terms after intratracheal administration of highly dispersed silicon dioxide powder against the background of uridine treatment. Penetration of powder particles into hepatocyte cytoplasm, nuclei, mitochondria, and peroxisomes and development of bacteria in these cells were observed. Uridine reduced the destructive effect of powder on the organelles, increased glycogen content in hepatocytes, and inhibited the formation of capsulated bacterial forms in these cells.

Electron microscopy and cytochemical study of alveolar tissue of rat lungs were performed at the early stage after intratracheal treatment with fine silicon dioxide powder. The preparation was administered to animals receiving or not receiving intravenous injection of uridine. Dust particles permeated the cytoplasm, mitochondria, and nuclei of cells in the air-blood barrier of the alveoli. Uridine decreased the severity of dust-induced damage to cells and increased intracellular glycogen content.

Weightlessness produces adaptive and maladaptive changes in the respiratory system. We assessed the effects of 30-day antiorthostatic hanging as a model of microgravity on the water balance in the lungs and surface activity and phospholipid composition of pulmonary surfactant in C57Bl/6 mice. Long-term antiorthostatic hanging increased water content in the lungs and reduced surface-active properties of the surfactant. This was accompanied by an increase in the content of alveolar phospholipids and changes in their fractional composition (increase in the relative content of lysophosphatidylcholine and phosphatidylethanolamine).

We studied the dependence of parameters of lung volumes and the elastic properties of the lungs on changes in the central hemodynamics occurring in the initial period of passive postural changes in cats. It was found that transition from the horizontal to head-up and head-down tilting was accompanied by opposite hemodynamic changes in the cranial and caudal parts of the body. Changes in lung compliance and functional residual capacity of the lungs were opposite and linearly depended on the intensity of hemodynamic shifts, which indicates passive character of the primary disorders primarily determined by a physical factor, gravity-dependent redistribution of body fluids.

Two once-weekly intravenous injections of the polyethylene oxide Polyox WSR-301 (yielding a blood concentration of the order of 5×10−6 g/ml) led to a 38% decrease in the area occupied by sudanophilic lesions in the aortic arch of rats fed an atherogenic diet for two weeks. Perfusion under constant pressure of the formalin-fixed vascular system in the posterior part of the body with physiological saline and then with polyethylene oxide (10−5 g/ml) was without effect in normal rats and in those with mild lipoidosis, but reduced hydrodynamic vascular resistance by 9–14.5% in rats with pronounced lipoidosis. Intravenous injection of polyethylene oxide into anesthetized rats with pronounced lipoidosis in doses that were subthreshold for normal rats (blood concentrations of the polymer were of the order of 10−7 g/ml) caused a 20% decrease in the total peripheral resistance to blood flow, with a 17–20% rise of the blood flow rate in the carotid artery.

NADPH diaphorase colocalized with nitric oxide synthase was studied in damaged protoneurons of the nodose ganglion of rabbit vagus nerve. The number and activity of nitric oxide synthase-expressing neurons increased. Nitric oxide is involved in neuron remodeling.

The mouse liver was fixed in 12 different kinds of fixative based on glutaraldehyde, paraform-aldehyde, picric acid, and lysine and the location of albumin was studied by an indirect immunoperoxidase method. Comparison of the results showed that the best method of fixation is by immersion in 8% paraformaldehyde solution. Albumin was found on ribosomes and nuclear membranes and on the granular endoplasmic reticulum and also in the matrix of the hepatocyte cytoplasm. It is suggested that newly synthesized albumin is secreted directly into the cytosol, from which it enters the extracellular space.

The indirect electron microscope immunoperoxidase method utilizing pure rabbit antibodies to protein of mouse amyloid fibrils was used for studying casein-induced amyloidosis in mice. At the early stages of amyloidosis there appeared deposits of fine granular material in the mouse myocardium. These deposits contained an antigen similar to the amyloid fibrils antigen, but the deposits had no fibrillar ultrastructure. The results testify to the presence of early nonfibrillar stage of amyloid formation.

The dynamics of the histopathological changes in albino rat embryos following administration of single teratogenic doses of pyrimethamine on the ninth day of pregnancy was investigated. The most sensitive structure to the action of pyrimethamine was found to be the decidual tissue, the first disturbances in which were observed as early as 1 h after treatment. The cells of the various germ layers reacted differently to pyrimethamine. The cytotoxic effect of the compound was particularly marked on the embryonic mesoderm and the extraembryonic ectoderm. It is concluded that hemodynamic disorders connected with disturbance of the decidual tissue play an essential role in the mechanism of the harmful action of some chemical teratogens on mammalian embryos.

Applied on the 6th day of gestation, aminopterin causes in rat embryos various malformations of the eyes, facial skull, brain, extremities, abdominal wall, tail, and spine. Aminopterin application somewhere later in pregnancy causes a high embryonic mortality but no malformations in surviving embryos.

Exposure to a pulsed electric current during reparative regeneration of bone in rabbits resulted in stimulation of osteogenesis so that it predominated over fibro- and chondrogenesis to a greater degree than inthe control. The degree of mineralization of the microstructures was indistinguishable from the control.

Experiments were carried out on Wistar rats which sustained at a sexually immature age a transient form of alloxan diabetes with subsequent stable elimination of hyperglycemia and glucosuria and with a normal test for tolerance to glucose. The average weight of 232 newly-born rats from these test rats was 7.3 (6.0–12.0), the average weight of 274 newly-born rats from healthy mothers being 6.5 (5.0–8.0). The difference is significant (P=0.05).

Experiments were conducted on rabbits. Changes in ATP in the regenerating bone tissue after incomplete osteotomy and removal of a bone section, and also in cases of reparative osteogenesis stimulation in the region of the bone defect by means of pulse electric current were studied. ATP content in the bone callus after incomplete osteotomy and electrostimulation proved to exceed such in the regenerating bone tissue following removal of the bone fragment when no stimulation was applied. On the basis of the data obtained it is suggested that improvement of energy provision of the fracture consolidation process was one of the important links in the mechanism of stimulating influence of the electric current on the reparative regeneration of the bone tissue.