Development of interneuronal synapses between anterior horn neuroblasts of the human spinal cord in early prenatal development (seventh to ninth weeks of gestation)

Synaptogenesis in presumptive anterior horn cells of the spinal cord (C4-T3) was studied by electron microscopy in early human prenatal development. The morphological stages of synaptogenesis were traced and the minimum structural organization of the synapse corresponding to the onset of its functional activity was identified. The possible mechanisms of synaptogenesis are postulated.Laboratory of Development of the Peripheral Nervous System, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 233–235, February, 1977.     

Extra- and intracellular collagen resorption by macrophages and fibroblasts in postpartum uterine involution

Localization of catepsin B in rat uterus during postpartum involution was studied by electron microscopy using histochemical methods. The product of histochemical reaction was found in collagen-containing vacuoles in macrophages and fibroblasts, on their cytolemma and adjacent collagen fibrils, which indicated the involvement of these cells into intra- and extracellular collagen resorption in the uterus.     

Subsynaptic units as a universal system-forming and regulating factor of brain synapses

Dense projections and postsynaptic density — specialized structures of the synaptic cytoskeleton — are regarded as a single functional system of subsynaptic units. From this viewpoint, interneuronal relations in health and after brain ischemia are analyzed. It is shown that hyperplasia and recombination of the system of subsynaptic units are the major mechanisms responsible for reorganization of functionally mature interneuronal junctions in the mammalian and human brain. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 4–12, July, 1997     

Surface activity of phosphatidylcholines as the basis for surfactant replacement therapy

Using the methods of surface balance we compared the effects of different phosphatidylcholines and synthetic surfactant Exosurf on the equilibrium surface tension at the air-water interface. It was found that dipalmitoyl-lecithin, the principal component of natural surfactant, and its synthetic substitutes can be replaced by other phosphatidylcholines, in particular, by modified soybean phosphatidylcholine phospholipon. It was demonstrated that equilibrium surface tension is an informative characteristic in the assessment of potential components for synthetic surfactants. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 2, pp. 168–170, February, 2000     

Hypertrophic synapses as a factor of formation of persistent pathological centers in the brain in the late postresuscitation period

Clinical death was modelled on albino rats. Synapses in the molecular layer of the cerebral sensorimotor cortex were investigated 1, 2, 3, 4, 5, 6, 7, 8, and 9 months postresuscitation. The total density of synapses peaked and the number of hypertrophic and perforated contacts increased 4, 7, and 9 months after resuscitation. The role of increased number of hypertrophic and perforated contacts in the pathogenesis of postresuscitation encephalopathy is discussed. Translated fromByuleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129 No. 5, pp. 532–535, May, 2000     

Role of the hormonal status of the father in involution of the thymus in the progeny

This study was aimed at assessing the consequences of the influence of exogenous androgens on the epididymal sperm of fathers for their progeny. A single injection of testosterone or dihydrotestosterone to adult rats caused a transient increase of the level of the corresponding androgen, later leading to augmentation of the androgen-dependent organs and loss of thymus weight. Hyperandrogeny and earlier age-associated involution of the thymus were observed in the male progeny of androgenized males of reproductive age. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 5, pp. 562–564, May, 1996     

Signal splitting as the basis for involvement of natural cytotoxicity system in endogenous biological retranslation

The ability of natural killers to split biological signal (dissociation of cytotoxic and interferon-producing activities) is the main precondition of the involvement of the natural cytotoxicity system in endogenous biological retranslation. Dissociation of the primary functions of natural cytotoxicity effectors is provided by enhanced interferon production against the background of decreased cytotoxicity of natural killers, or by enhanced natural cytotoxicity against the background of almost complete inhibition of interferon production. Dissociation of the primary functions of natural killers is a physiological phenomenon; it is induced and maintained by factors, which are not directly connected with induction or suppression of the immune response. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 12, pp. 604–612, December, 1999     

Prediction of the resistance to hypoxia on the basis of modifications of the adenine nucleotide system

An empirical dependence allowing one to identify rhythmic fluctuations of stable and unstable state in respect of hypoxia in the process of adaptation has been developed on the basis of long-term investigation of changes in brain content of adenine nucleotides upon “hypobaric training” of rabbits. The function approximating this dependence enables one to predict the effective number of “hypobaric training” sessions providing for the adaptive reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 4, pp. 391–394, April, 1997     

Localization of sites where abnormal miniature end-plate currents arise at the myoneural junction

Frog cutaneous-sternal muscle preparations were used to examine mechanisms by which extracellularly recorded abnormal miniature postsynaptic signals are generated. The frequency of these signals was found to increase after denervation as well as after the addition of 4-aminoquinolinic acid (0.25 mmol/liter) and emetine (10 mmol/liter) to the solution perfusing the preparation. Graphic delineation, using a 3-electrode technique, of the sites where signals were arising in the nerve terminal showed that neurotransmitter (acetylcholine) quanta responsible for the generation of postsynaptic signals emerged in limited areas of the myoneural junction between terminal portions of the active zones instead of being released from the latter. It is concluded that the source of such quanta is most likely to be the Schwann cell and that the mechanism via which the neurotransmitter is released from this cell is distinct from the mechanism of its release from the nerve terminal. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 235–238, September, 1995 Presented by A. D. Ado, Member of the Russian Academy of Medical Sciences     

Neuromorphological basis of the therapeutic effect of neurohumoral agents of the cerebrospinal fluid

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 7, pp. 79–80, July, 1993     

Cardiotoxic effects of the antiarrhythmic rhythmidazol and their correction by suphan, befol, and their combinations

The antiarrhythmic rhythmidazol produces a cardiotoxic effect that can be corrected by suphan, befol, and their combinations, as evidenced by normalization of ultrastructural organization of cardiomyocytes and myocardial oxygen consumption by these drugs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 12, pp. 640–644, December, 1997     

Genetic basis of adenylatecyclase regulation of testosterone production of Leydig's cells in laboratory mice

The function of Leydig's cells during stimulation of various components of the adenylatecyclase system was studied in inbred mice of various lines. Mice of different lines were found to differ markedly in their production of testosterone during stimulation of a crude Leydig's cell suspension with ascending concentrations of chorionic gonadotropin, cholera toxin, forskolin, and dibutyryl-cAMP. The ranking of the lines according to the maximal production of testosterone was virtually the same during exposure to steroidogenesis activators. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 177–179, August, 1994 Presented by L. E. Panin, Member of the Russian Academy of Medical Sciences     

Structural basis of changes in deformation of synaptic contacts of the sensorimotor and cerebellar cortex in health and acute ischemia

Paramembranous specialized formations of the synaptic cytoskeleton — dense projections and postsynaptic condensation of axospinous synapses of the molecular layer of white rat sensorimotor and cerebellar cortex — in health and acute total ischemia are studied by selective contrast staining with phosphotungstic acid. A direct relationship is revealed between the pattern and degree of deformation of the contact plane, on the one hand, and the postsynaptic condensation and ratio of the volumes of pre- and postsynaptic accumulations of paramembranous filaments, on the other. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 443–445, April, 1995 Presented by L. V. Poluektov, Member of the Russian Academy of Medical Sciences     

Evaluation of the antipyretic effect of psychotropic agents and their influence on the fever-lowering effect of acupuncture

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 115, N ⁰ 3, pp. 262–264, March, 1993     

Sex steroids and their receptors in patients with tumors of the pancreas

A tendency toward an increase in serum content of sex steroid-binding globulin and a decrease in the total concentration of testosterone and its free and globulin-bound fractions and in the index of free androgens was observed in patients with pancreatic cancer. There were no statistically significant differences in baseline serum levels of hypophyseal hormones and prolactin in male patients and in the control. One or both types of steroid hormone receptors, the content of androgen receptors being higher than that of estrogen receptors, varying in a wide range were detected in 71% of the patients with malignant neoplasms. The occurrence of steroid hormone receptors was higher in adenocarcinomas, while their content was significantly higher in normal pancreatic tissues. The occurrence of androgen receptors was higher in male patients at the early stages of the disease, predominantly in highly differentiated adenocarcinomas located in the body of the pancreas. The content of androgen receptors was higher in male patients, in metastasizing tumors, in adenocarcinomas located in the body of the pancreas, and in patients without clinical and laboratory evidence of the mechanical jaundice syndrome. The content of androgen receptors positively correlated with the maximum size of the tumor. Translated fromByulleten' Eksperimental'noi Biologii, I Meditsiny, Vol. 126, No. 8, pp. 197–200, August, 1998     

Effect of deoxycorticosterone acetate administration to pregnant rats on the brain of their offspring

Effects of deoxycorticosterone acetate injected to rats on gestation days 18 and 20 on morphometric indexes of the brain and RNA concentration in neurons of neocortical layer V in 1-day-old offspring were studied. The brain in 1-day-old prenatally treated rats was more developed than in the offspring of intact and control females. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 4, pp. 390–392, April, 2000     

Reactive properties of epi- and perineurium: Experimental and morphological basis for nerve suture technique

Epi- and perineurium were examinedin vitro and during regeneration after mechanical damage. Epithelial type of culture growth and reparative regeneration of the perineurium were established, connective tissue of the epineurium served as the substrate and trophic factor in these processes. We used histogenetic method of coaptation and of epi- and perineural micosutures in a damaged nerve trunk. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 211–215, August, 2000     

Responses of the arterial and venous vessels of the skeletal muscle to norepinephrine following damage to their endothelium

The functional activity of vascular endothelium in a muscle preparation from the feline gastrocnemius is impaired with ethanol, which results in an increase of an adrenergic responsiveness of the arterial compartment of the vascular bed. The exchange function of the microvessels changes little. Veins exhibit nonuniform changes in their responsiveness after exposure of their endotheliocytes to ethanol. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 315–318, September, 1994