The use of nanocomposite coatings with various physicochemical properties in tissue engineering.

We studied the effect of nanocomposite coatings with various physicochemical properties on the structural and functional properties (adhesion potential, phenotype, gene expression) of mesenchymal stem cells. Of all tested nanocoatings (Al2O3, ZrO2, Ta2O5), oxide coating Al2O3 enriched in vitro monolayer bone marrow cell culture with cells carrying mesenchymal stem cells phenotype markers and stimulated expression of ido gene, which can confer new therapeutic potencies to these cells and extend their application in clinical practice.

[The resistance of low brainstem tissue to free radical oxidation in rats during periodic breathing following hydroxybutyrate treatment].

We evaluated tissue resistance to free radical oxidation, in pentobarbital-anesthetized mongrel albino male rats during pathologic periodic breathing following hydroxybutyrate (GHBA) administration. It was shown that GHBA modulated pro- and antioxidant status of brain tissue. In the absence of periodic breathing after GHBA, decreases in resistance of brainstem tissue membranes to induction of free radical oxidation were slightly pronounced. Rats with GHBA-induced periodic breathing exhibited increased membrane sensitivity of medullar neurons to induction of free radical oxidation. We suggest that cellular metabolism and/or membrane mechanisms of respiratory rhythm-generating neurons play a role in the pathogenesis of periodic breathing.

GABA representation in hypoxia sensing: a ventilatory study in the rat.

Phenibut, a nonspecific GABA derivative, is clinically used as an anxiolytic and tranquilizer in psychosomatic conditions. A GABA-ergic inhibitory pathway is engaged in respiratory control at both central and peripheral levels. However, the potential of phenibut to affect the O2-related chemoreflexes has not yet been studied. In this study we seek to determine the ventilatory responses to changes in inspired O2 content in anesthetized, spontaneously-breathing rats. Steady-state 5-min responses to 10% O2 in N2 and 100% O2 were taken in each animal before and 1 h after phenibut administration in a dose 450 mg/kg, i.p. Minute ventilation and its frequency and tidal components were obtained from the respiratory flow signal. We found that after a period of irregular extension of the respiratory cycle, phenibut stabilized resting ventilation at a lower level [20.0±3.3 (SD) vs 31.1±5.2 ml/min before phenibut; P<0.01]. The ventilatory depressant effect of phenibut was not reflected in the hypoxic response. In relative terms, this response was actually accentuated after phenibut; the peak hypoxic ventilation increased by 164% from baseline vs the 100% increase before phenibut. Regarding hyperoxia, its inhibitory effect on breathing was more expressed after phenibut. In conclusion, the GABA-mimetic phenibut did not curtail hypoxic ventilatory responsiveness, despite the presence of GABA-ergic pathways in both central and peripheral, carotid body mechanisms mediating the hypoxic chemoreflex. Thus, GABA-mediated synaptic inhibition may be elaborated in a way to sustain the primarily defensive ventilatory chemoreflex.

Effects of electrical stimulation of respiratory center in the event of termination of its natural rhythmic activity.

The possibility of restoration of the natural rhythmic activity of the respiratory system by transcutaneous electrical stimulation of the respiratory center after termination of spontaneous respiratory movements caused by narcosis was shown in experiments on mongrel cats of both sexes under nembutal anesthesia. Natural rhythmic activity of respiratory center was stopped by additional administration of sodium thiopental. The proposed method of electrical stimulation of the respiratory center allows maintaining the rhythmic respiratory movements and their recovery after narcotic apnea up to complete recovery of spontaneous respiration.

[Electrical stimulation of breathing].

We have generalized data on different breathing electrostimulation methods and have shown their merits and demerits. We have presented electrostimulation methods, the electrostimulators description, different variants of electrodes site, parameters influence. It has shown advantages breathing electrostimulation application in a medical practice.

[Experience with vascular biografts "KemAngioprotez" in reconstructive surgery of lower-limb major arteries].

Presented herein is the experience with the Russian-made vascular biografts "KemAngioprotez" in 149 patients suffering from atherosclerotic occlusions of the major arteries of the lower extremities and in one female patient with an injury to the superficial femoral artery. A total of 150 reconstructive operations were performed on all segments of the major arterial bed of the lower limbs. The early postoperative period was accompanied by 14 thromboses of the vascular biograft after femoropopliteal reconstruction. It was determined that the likelihood of thrombosis of the vascular biograft depended upon the type of the distal anastomosis, increasing in establishing an "end-to-side" distal anastomosis with the popliteal artery as compared with the "end-to-end" anastomosis technique. No cases of either aneurysmatic deformity, rupture of the vascular graft nor its infection in the early postoperative period were observed. The vascular biograft proved convenient and may therefore be successfully used to replace synthetic vascular grafts and autovenous transplants in reconstruction of the external iliac, femoral and popliteal arteries.

[Effect of phenibut on the respiratory arrest caused by serotonin].

The role of the GABAergic system in mechanisms of the respiratory arrest caused by serotonin administration was studied in anaesthetized rats. Under normal conditions, the systemic administration of serotonin (20-60 mg/kg, i.v.) resulted in drastic changes of the respiratory pattern, whereby the initial phase of increased respiratory rate was followed by the respiratory arrest. The preliminary injection of phenibut (400 mg/kg, i.p.) abolished or sharply reduced the duration of the respiratory arrest phase induced by serotonin. Bilateral vagotomy following the phenibut injection potentiated the anti-apnoesic effect of phenibut, which was evidence of the additive action of vagotomy and phenibut administration. The mechanism of apnea caused by serotonin administration is suggested to include a central GABAergic element, which is activated by phenibut so as to counteract the respiratory arrest.

[Atherosclerosis/calcinosis of the carotid and peripheral arteries in patients with initial and terminal stages of chronic renal failure].

AIM: To perform ultrasound dopplerography (UD) investigation of severity and prevalence of atherosclerosis/calcinosis of the central and peripheral arteries in patients with chronic renal failure (CRF); to estimate correlation between the vascular lesions and cardiovascular risk factors. MATERIAL AND METHODS: UD of major arteries and echocardiography were made in 46 patients with CRF: 10 patients with initial CRF (creatinine 1.4-2.2 mg/dl) and 36 patients with terminal CRF on hemodialysis. RESULTS: Calcinates and atherosclerotic plaques were registered in the carotid and femoral arteries of all the patients. Atherosclerotic lesion was more frequent than calcinosis in the carotid arteries. Calcinosis was more frequent in the femoral arteries. The popliteal and tibial arteries were affected only by calcinosis which occurred in 20% patients with initial and 44.4% patients with terminal CRF. Calcinosis severity increased with progression of CRF while atherosclerosis severity depended more on the patients' age than on severity of CRF. The pulse wave speed in the carotid and femoral arteries was higher in marked left ventricular hypertrophy, seven (19.4%) of these patients had reduced ejection fraction of the left ventricle < 40%. CONCLUSION: Compound atherosclerotic/calcinosis lesion of the vessels is registered at early stages of CRF and progress with progression of renal failure.

Experimental therapy of graft-versus-host disease by mesenchymal stromal cells grown on oxide nanocoatings.

Immune aggression to transplanted allogeneic bone marrow, i.e. the graft-versus-host disease (GVHD), could be decreased by the suppression of effector and/or activation of T- regulatory cells (Treg). This task could be solved by co-transplantaiton of allogeneic bone marrow and mesenchymal stromal cells (MSCs). This study demonstrated the elevated immune modulating activity of MSCs by their culturing in vitro on Al203 oxide nanocoatings. Introduction of the cells to the animals with GVHD resulted in an increased content of Treg in the spleen of bone marrow recipients, reduced severity of the pathology, and higher survival of animals. Thefindings could be the basis for developing the new approaches to optimize the GVHD treatment methods involving the oxide nanocoating cultured MSCs.

[Calcification of peripheral arteries in patients with terminal renal failure on programmed hemodialysis].

AIM: To estimate incidence and clinical significance of carotid and femoral arteries calcification in patients with terminal renal failure (TRF) on programmed hemodialysis (PH). MATERIAL AND METHODS: Thirty four patients (25 males and 9 females) with TRF were divided into two groups by severity of hyperphosphatemia: 15 patients with P < 6 mg/dl (group 1) and 19 patients with P > 6 mg/dl. The groups were matched by age (44.4 +/- 15.05 and 42.7 +/- 14.23 years, respectively) and PH duration (2.4 +/- 1.1 and 2.6 +/- 1.16 years, respectively). Calcification of the arteries and structure of the vascular wall were examined with ultrasonic dopplerography of the common carotid and femoral arteries. Measurements were made of intima-media complex (IMC) thickness, systolic and diastolic diameter of the right and left carotid artery. The arteries were studied for the presence of calcinates and atherosclerotic plaques. RESULTS: Patients of group 2 showed a correlation between a P level, incidence rate of common carotid arteries calcification, atherosclerotic plaques in the femoral arteries, IMC of the carotid and femoral arteries, left ventricular hypertrophy and a decline in a left ventricular diastolic function. A significant correlation was established between the rate of atherosclerotic plaques detection and age, male sex, smoking and history of PH. An increase in IMC and arterial rigidity was revealed in 12 (63.2%) of 19 patients of group 2. They had episodes of intradialysis hypotonia, 6 (31.6%) patients had acute coronary syndrome, 5 (26.3%) patients--cardiac arrhythmia. CONCLUSION: A significant contribution to formation of risk factors of cardiovascular complications in TRF patients on PH is made by disturbed phosphorus-calcium metabolism resulting in higher rigidity and diameter of the arteries. The above changes lead to a rise in systolic pressure and fall in diastolic one. Increased pulse pressure is an independent predictor of the risk to develop acute coronary syndrome.

[Respiratory regulation during neuronal hyperactivation of the respiratory center]. / Reguliatsiia dykhaniia pri giperaktivatsii neironov dykhatel'nogo tsentra.

The responses of breathing and of respiratory neurons to microinjections of penicillin into the respiratory center area were studied in anesthetized and spontaneously breathing rats. The injections caused different alterations of the respiration, of the activity of respiratory neurons and their spatial distribution, and initiated respiratory moments of apneustic and gasping types. the hyperactivation of the respiratory center neurons by penicillin seems to cause a reversible development of pathological types of respiration.

[Intradialysis hypotension: causes and sequelae]. / Intradializnaia gipotoniia: ee prichiny i posledstviia.

AIM: To study causes and sequelae of intradialysis hypotension (IH) in patients with terminal renal failure (TRF). MATERIAL AND METHODS: Forty one patients with TRF on chronic hemodialysis (CH) were divided into two groups. The study group consisted of 24 patients with episodes of IH. Seventeen patients of the control group had no IH. All the patients were examined with assessment of protein-energy deficiency, residual renal function, left-ventricular hypertrophy, diastolic function of the heart. Hemodialysis effectiveness was estimated by Kt/V index. Survival of the patients was calculated according to Kaplan-Meier method. RESULTS: In the study group IH episodes occurred in spite of low ultrafiltration velocity (8-10 ml/min). Those patients of the study group who had IH associated with polyneuropathy and left-ventricular hypertrophy had IH episodes more often and sharper falls of arterial pressure. Long-term IH decreased survival significantly. CONCLUSION: Repeated episodes of IH deteriorate effectiveness of hemodialysis because of acute coronary syndrome, acute disorder of cerebral circulation, complications of deficient dialysis syndrome (pericarditis, hyperkaliemia, pulmonary edema, congestive heart failure).

[Computed tomography in the diagnosis of pulmonary thromboembolism]. / O vozmozhnosti primeneniia komp'iuternoi tomografii v diagnostike tromboémbolii legochnoi arterii.

To verify the hypothetical diagnosis of pulmonary thromboembolism (RTE), 64 patients were provided CT of the chest organs with pulmonary artery opacification, Twenty-seven patients had thromboemboli in different parts of the vascular tree. In 9 patients, the thromboemboli were parietal, with flow preservation at the site of thromboembolus fixation, and in 18 patients, the emboli occluded the vascular lumen. In 11 patients with occlusion of the segmental and subsegmental arteries, the clinical course of RTE, in addition to acute cardiovascular insufficiency, was marked by cough, hemoptysis and pneumoinfarction; the tomograms showed well-defined parts of pneumoinfarction and pleural exudate. In the event of non-occlusion thromboembolism, the clinical picture was only marked by acute cardiovascular insufficiency. In 37 patients, no thromboemboli were discovered in the system of the pulmonary artery. Of these, 27 patients presented, however, with some other pathology of the chest organs.

[Experience with the treatment of suppuration surrounding synthetic vascular prostheses]. / Opyt lecheniia pri nagnoenii vokrug sinteticheskikh sosudistykh protezov.

Experience with the conservative and operative treatment of suppurations around vascular prostheses in 16 patients is presented. Spread of the purulent inflammation around prostheses from the place of primary suppuration on the femur up to the portions proximal to the inguinal ligament was taking place within the first 1-2 weeks after the appearance of the first symptoms of suppuration. Partial resection of infected portions of the prostheses and substitution of them by autovenous grafts are thought to be more expedient within these terms. Such operations are less traumatic and technically more simple than interventions associated with a complete ablation of aorto-femoral prostheses and a simultaneous substitution of them by new vascular prostheses or transplants.

[Respiratory reactions on microinjections of GABA and baclofen into the Bötzinger complex and the pre-Bötzinger complex in rats].

In adult anaesthetized rats the respiratory reactions to microinjections of GABA (10(-5) M) and baclofen (10(-6) M) into Botzinger complex (BC) and pre-Botzinger complex (PBC) were investigated. It was shown, that GABA microinjections into BC shortened inspiratory time and extended expiratory time while respiratory rate was not changed essentially, under this conditions the tidal volume and ventilation were increased. GABA microinjections into PBC significantly inhibited respiratory rhythm due to inspiratory and expiratory time prolongations and reduced tidal volume. The microinjections of baclofen into BC reduced expiration time and ventilation, and increased respiratory frequency whereas microinjections into PBC increased tidal volume without respiratory rate and expiratory time changes. It is suggested that the reactions observed demonstrate the various contribution of GABAergic mechanisms, including GABA(B)-receptors within BC and PBC, in control of respiratory pattern parameters.