Ultrastructural changes in the sympathetic ganglia in experimental burn trauma

Ultrastructural changes of neurones of sympathetic vegetative nervous ganglia were studied in 15 white male rats at an age of 5-7 months. In the dynamic of postmortem changes disorders typical of hypoxic conditions of the chest predominated.     

Ultrastructural study of lymph node cells in experimental burn injury

Ultrastructure of the lymph nodes was examined in rats with experimental thermal burns of the skin. Ultrastructural studies of lymph node cells demonstrated the signs of destruction at the ultrastructural level. In the authors' opinion, destructive changes in lymph node cells may form the structural basis for secondary immunological deficiency typical for burn injury.     

Effect of transplantation of embryonic neural tissue on the dynamics of brain edema following experimental craniocerebral trauma

The effect of transplantation of embryonic neural tissue (ENT) on the dynamics of brain edema following heavy craniocerebral trauma (CCT) made to the left parietotemporal area was studied in rats. The brain tissue impedance was measured in the damaged and contralateral hemispheres 1 to 30 days after the trauma in the animals of three groups: (i) without any procedures after the CCT, (ii) with surgical treatment of the damaged brain area, and (iii) with transplantation of 1–2 mm³ sensorimotor cortex fragments from 18-day-old rats grafted into the cavity created by this treatment. At the first day after CCT, the impedance in the damaged hemisphere decreased by 30–37%, while the impedance in the contralateral hemisphere decreased approximately by 20%, compared with the control, which was evidence of the development of intensive generalized edema. In the group of animals with the ENT transplantation, the edema involuted noticeably faster than in the other two groups: the mean impedance value reached 97.9% of the control value (before the damage) already by the 7th post-traumatic day. Complete recovery of the impedance by the 30th day was observed only in the animals with transplantation. The adequacy of an impedancemetric technique for investigation of the dynamics of water-electrolyte re-distribution in the brain tissue, and the mechanisms underlying corrective effect of ENT transplantation on the edema dynamics in the post-traumatic period are discussed.     

The study of cytokine content and ganglioside metabolism in experimental brain edema

A blood cytokine profile and also the brain content of lipid peroxidation (LPO) products and gangliosides were investigated in rats with experimental brain edema. The development of brain edema was accompanied by the increase in pro-inflammatory and a decrease in anti-inflammatory cytokine content. In parallel, accumulation of LPO products (conjugated dienes, hydroperoxides, and malondialdehyde) was observed. The study of ganglioside content under conditions of experimental brain edema revealed a decrease of their hydrolytic degradation product, sphingosine.     

Stress analgesia in experimental burn shock

Experiments with curarized and slightly anesthetised adult cats with burn shock have demonstrated pronounced depression of excitation transmission in associative and nonspecific afferent systems during somatic, sound and light stimulation. Effects controlling the activity of the cardiovascular system were facilitated in efferent systems. In white rats, burn shock led to an increase in the somatic and visceral pain threshold during the first 5 days. Rausedyl and naloxone reduced stress analgesia caused by burn shock in white rats. Burn shock enhanced opiate-like activity (beta-endorphine, beta-lipotropin) of the white rat forebrain as shown by radioimmunoassay. The data suggest that stress analgesia associated with experimental burn shock is likely to be accounted for by the increased production of endogenous opiates.     

Dynamic changes of brain serotonergic and dopaminergic activities during development of anxious depression: experimental study

Chronic psychoemotional stress of social defeats produces development of experimental anxious depression in male mice similar to this disorder in humans. 5-HT and 5-HIAA levels, TPH and MAO A activities, 5-HT1A-receptors in different brain areas were investigated at different stages of development of experimental disorder. It has been shown that initial stage (3 days of social stress) is accompanied by increase of 5-HT level in some brain areas. Decreased 5-HIAA levels in the hippocampus, amygdala and nucleus accumbens were discovered at the stage of forming depression (10 days of social stress). Pharmacological desensitisation and decreased number of 5-HT1A-receptors were shown in frontal cortex and amygdala. At the stage of pronounced depression (20 days of stress), there were no differences in 5-HT and 5-HIAA levels in all brain areas (excluding hypothalamus) of depressive animals. However increased number of 5-HT1A-receptors and decreased affinity in amygdala and decreased TPH and MAOA activities in hippocampus were found in depressive mice. Hypofunction of serotonergic system is suggested at the stage of pronounced depression state in animals. Similar processes had place in brain dopaminergic systems. It is concluded that dynamic changes of brain monoaminergic activities accompany the development of anxious depression in animals. Various parameters of monoaminergic systems are differently changed depending on brain area, mediator system and stage of disorder.     

Pulmonary circulation in experimental toxic edema of the lungs

By means of ultrasonic method used in acute experiments on cats with open chest under artificial lung ventilation the authors studied the blood flow in low-lobar pulmonary artery and the vein, the blood pressure in pulmonary artery as well as the balance between output of right and left ventricles in experimental pulmonary edemas caused by intravenous infusion of mixture fatty acids. It was shown, that acute injury of lungs vessels produces redistribution of blood flow to the lesser circulation, increases the pressure in pulmonary artery. The pattern of pulsating blood flow in lobar artery and vein changes. The authors assume that in situation, when lung vessels permeability is already deranged redistribution of the blood to the lesser circulation aggravates the degree of edema.     

The status of lymphocytes from immunocompetent organs in the development of experimental tumors from 1H-NMR data

Thymus and lymph node lymphocytes in L-1210 ascite lymphoma, Lewis tumor, 22a hepatoma have been studied by NMR. Lymphocyte 1H-NMR spectra can to a certain extent reflect the state of immune system of an organism, in particular, they can sense both transformation of lymphocytes, and development of several tumors which are not accompanied by transformation of lymphocytes. In the latter case, changes in lymphocyte spectra takes place at terminal stages of carcinogenesis and are less pronounced than at transformation of lymphocytes. NMR spectra parameters can also distinguish between reaction of males and females to tumor formation.     

Changes in the respiratory organs in experimental adenovirus infection

An experiment on 6 green monkeys and on 286 cotton newly born rats was made with the aim of studying the lung during experimental adenovirus infection. All the animals during different terms of infection (from 6 hours and up to 40 days) have been studied. Several morphological changes were discovered in the lungs of monkeys and rats after 6 hours of infection and were retained up to the 10-th day of infection. All the components of air-blood barrier and basal membranes were involved in the process, but after 20 day of the experimental adenovirus infection the entire restoration of cellular structure occurred.     

Histophysiology of the microvascular bed in experimental trauma

1. Morphohistological changes in a focus of spinal cord trauma have a phasic character, with a period of primary lesions (5-30 min after traumatization) and a period of secondary lesions (1-23 h after traumatization). 2. Variation of transport enzyme activities in the walls of the microvessels of the traumatized spinal cord is characterized by an undulating course and by asynchrony of the peaks of Mg-dependent ATPase and alkaline phosphatase activity. 3. With reference to the rapid drop in the given enzyme activities and to progressive necrotic changes in the traumatized spinal cord, it is desirable that the cord circulation should be corrected within the first few hours after traumatization.     

Candidal carriage and the development of invasive candidiasis of the organs of the digestive tract during experimental immunodepression

After infecting healthy mice with Candida by their oral administration the fungi are rapidly eliminated from the digestive tract. In the animals, immunosuppressed by the injection of cyclophosphamide, the prolonged persistence of Candida in the digestive tract occurs, and the administration of Candida in considerable doses over prolonged periods in combination with the injections of high doses of immunosuppressing agents results in the development of profound invasive lesions, in some cases leading to the dissemination of the process.