Comparative Study of Sutureless Fixation of Lightweight Surgical Meshes for Hernia Repair in a Rat Model.

The aim of this study was to compare the efficacy of different methods of sutureless fixation of lightweight meshes made of different polymers for repair of experimental hernias. Two lateral hernia defects were modeled in male rats and covered with polyester and polypropylene prostheses. The meshes were fixed with Histacryl glue (group 1), or self-gripping meshes were used (group 2), or the meshes were implanted without fixation (group 3). On day 5 after surgery, mesh position and efficiency of fixation were evaluated. It was found that fixation is necessary for all light surgical meshes. Polyester meshes demonstrated better adhesive properties than polypropylene meshes. The most pronounced differences in the adhesive properties were found for self-gripping prosthesis, while in the groups with glue fixation, the differences were less pronounced.

Histoenzymological Characteristics of Smooth Muscle Cells in Myocardial Vessels: A Comparative Study under Conditions of Increased Left or Right Ventricular Afterload.

Histoenzymological methods were used to study metabolism of smooth muscle cells of intramural myocardial arteries during experimental aortic or pulmonary artery stenosis. Aortic stenosis was accompanied by changes in smooth muscles of the left ventricle manifested by deceleration of tricarboxylic acid cycle, inhibition of oxidation of free fatty acids and their metabolites, flux redistribution in the glycolytic cascade, and inhibition of shuttle systems and biosynthetic processes. Similar metabolic alterations were observed in vessels of the ventricular septum, but they were not revealed in vessels of the right ventricle (except glycolysis stimulation). Under conditions of pulmonary artery stenosis, histoenzymological alterations in vascular smooth muscle of both ventricles and ventricular septum were similar, which attested to acceleration of tricarboxylic acid cycle, stimulation of oxidation of the free fatty acids with their metabolites, acceleration of glycolysis, and activation of the shuttle systems and biosynthetic processes. Comparative analysis of histoenzymological alterations revealed substantial differences in the character of metabolic changes under conditions of increased left and right ventricular afterload, which can be caused by peculiarities in myocardial blood flow, severity of circulatory disorders, severity of hypoxia, and intensity of processes maintaining ionic homeostasis in vascular smooth muscles and transport across the histohematic barriers. The data attest to important metabolic role of glycolysis in vascular smooth muscles of the myocardium, especially under conditions of enhanced afterload of the right ventricle.

[FACTORS AFFECTING SPERMATOGENESIS PRESERVATION IN RATS WITH SEMINIFEROUS TRACT OBSTRUCTION].

The aim of the study was to examine the effect of the seminal tract obstruction of different degree and duration on the morphological and functional condition of testicular tissue. The study was conducted in 50 male Wistar rats. Three experimental models of seminiferous tract obstruction were set up: obstruction of the proximal part of the ductus deferens, obstruction of the distal part of the ductus deferens and obstruction of at the epididymis level. Morphological evaluation of testicular tissue was performed at 3 and 6 months after the obstruction. It was found that obstruction at the epididymis level caused the most severe impairment of spermatogenesis.

Comparison of biomechanical properties of light mesh endoprostheses with different structural characteristics.

Three types of light mesh endoprostheses with different jersey structure were implanted into the anterior abdominal walls of 18 rabbits. Changes in the geometrical size and mechanical properties of the prostheses detected 3 months after implantation largely depended on the jersey structure and distribution of mature connective tissue in the structure of the material.

[Changes in reactivity of the contractile system of the small intestine caused by disturbed parasympathetic innervation]. / Izmenenie reaktivnosti sokratitel'nogo apparata tonkoi kishki v usloviiakh narushennoi parasimpaticheskoi innervatsii.

We studied the role of parasympathetic division of vegetative nervous system in regulation of the intestine activity in rats subjected to bilateral subdiaphragmal vagotomy, the response of the neuromuscular apparatus of the small intestine to stimulation by aceclydine taken as an example. Intravenous injection of aceclydine (0.5 mg/kg) into intact animals is accompanied by characteristics changes in the electrical and contractile activities of the intestine, which reflect its enhanced motor activity. Vagotomy leads to changes of response of the intestine to pharmacological stimulation, most expressed within 3, 7, and 30 days. It was proposed that distortion of reactive properties of the intestine contractile system under these conditions is related to functional changes in rhythm-setting neurons of intramural ganglia and M-cholinoreceptors of neuromuscular synapses.

[The role of the parasympathetic nervous system in regulating the kinetics of the regional blood circulation in the digestive system organs]. / Rol' parasimpaticheskoi nervnoi sistemy v reguliatsii kinetiki regionarnogo krovoobrashcheniia v organakh pishchevaritel'noi sistemy.

Cranio-bulbar part of the parasympathetic nervous system proved to be important for regulation of the blood flow distribution between the organs of the gastroduodenal complex (liver, stomach, and small intestine), rate of the local blood flow and its kinetics. Investigation of the blood supply of the above mentioned organs various periods (1-60 days) after bilateral subdiaphragmatic truncal vagotomy has demonstrated the most pronounced transformations in macro- and micro-hemodynamics in the 14-30 days period. Time pattern of these changes has one maximum in liver and stomach (14-30 days) and two maxima (7 and 30 days) in small intestine.

[Postoperative electromyographic monitoring of small intestine function in patients with peritonitis and acute intestinal obstruction]. / Electromiograficheskii kontrol za funktsionalnym sostoianiem tonkoi kishki u bolnykh s peritonitom i ostroi neprokhodimostíu kishechnika v posleoperatsionnom periode.

In 49 patients with general peritonitis and acute ileus, the authors used the method of direct electromyography. On the basis of analysis of the results, the functional state of the intestine, dynamics of its motor activity, effectiveness of the treatment performed were assessed and outcome of the disease was predicted.

[The diagnosis of motor disorders of the small intestine in peritonitis in children and the rationale for pathogenetic methods of correction]. / Diagnostika dvigatel'nykh narushenii tonkoi kishki pri peritonite u detei i obosnovanie patogeneticheskikh metodov korrektsii.

The work deals with the results of experimental (200 animals) and clinical (20 patients) study into the role of the efferent link of the autonomic nervous system in regulating motor activity of the small intestine and the possibility of using direct electroenteromyography in the diagnosis of the stages of paresis and the degree of motor disorders in peritonitis. The pathogenetic methods of treatment of intestinal paresis are substantiated. Medicamentous stimulation of the cholinergic nervous system in peritonitis is effective only when intactness of the intramural ganglia is maintained, in which case the electroenteromyographic test with neostigmine methylsulfate or cerucal may be conducted. The pathogenetic method of treatment in all other cases is medicamentous blockade of the adrenergic nervous system.

[An electromyographic method for determining the antihypoxic activity of preparations]. / Elektromiograficheskii metod opredeleniia protivogipoksicheskoi aktivnosti preparatov.

To measure drug antihypoxic activity, an electromyographic method was worked out. The main idea of the method is to estimate the influence of these substances on the amplitude of slow electric waves of smooth muscles on an isolated strip of rat small intestine in situ. This parameter whose value directly depends on tissue pO2 was recorded under the conditions of artificial ischemia of the intestinal strip. Circulatory hypoxia was simulated by the clamping of mesentery vessels, and the time was determined, during which the amplitude of slow electric waves reduced to 1/3 of the initial value in control animals and rats treated beforehand with the drugs under study. Antihypoxic activity of the drugs was calculated as difference in these time intervals between experiment and control, given in per cent.

[Effects of sodium hypochlorite on oxygen balance and functional state of the small intestine in experimental peritonitis]. / Vliianie gipokhlorita natriia na kislorodnyi balans i funktsional'noe sostoianie tonkoi kishki pri éksperimental'nom peritonite.

Sodium hypochlorite, administrated intravenously and intraperitoneally, leads to normal oxygen balance, metabolism and motility of small intestine in peritonitis. Anti-hypoxia effect of this substance is realized by an increase of oxygen content in the blood. It is useful to use sodium hypochlorite in general peritonitis for antibacterial therapy and against tissue hypoxia without side effects.

[Use of dibunol in pharmacological correction of post-vagotomy hypoxia of digestive organs in rats]. / Primenenie dibunola dlia farmakokorrektsii postvagotomicheskoi gipoksii pishchevaritel'nykh organov u krys.

1, 7, 14, 30 and 60 days after bilateral sub-diaphragmatic truncal vagotomy tension of oxygen (pO2) in liver, stomach and small intestine (jejunum) was determined. It was demonstrated that vagotomy leads to a decrease of pO2 in all investigated organs 1 day after the operation (such changes were observed in sham-operated rats) and 30 days, in jejunum--after 7 days, in liver--after 14 days, in stomach--after 60 days. Dibunol introduction in vagotomized rats during 29 days (starting from the second day after operation) results in pO2 normalization in all investigated organs.

[The role of the parasympathetic nervous system in regulating the oxygen tension and regional blood flow in the digestive organs of rats]. / Rol' parasimpaticheskoi nervnoi sistemy v reguliatsii napriazheniia kisloroda i regionarnogo krovotoka v organakh pishchevaritel'noi sistemy u krys.

The input of parasympathetic region of vegetative nervous system in regulation of regional blood transfer and maintaining of oxygen balance in organs of rat digestive system has been estimated by measuring oxygen tension (pO2) and the rate of regional blood transfer (RBTR) in liver, gut, and small intestine after 1, 7, 14, 30, and 60 days after vagotomy. Vagotomy was shown to lead to the decrease of pO2 in liver (1, 14, 30 days), gut (1 day), and small intestine (7 and 30 days). At initial postoperation period (1 day), the decrease in pO2 is accompanied by the increase in RBTR (in gut and small intestine), and at late period, by the decrease of RBTR in liver. The correlation between the decrease in pO2 and the decrease in RBTR allows to conclude that the hypoxia developing in liver after vagotomy is of a circulatory nature.