Esophageal tissue engineering: Current status and perspectives.

Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials.

[The number and size of human ventricular cardiomyocytes and the number of nuclei in them]. / Chislo i razmery zheludochkovykh kardiomiotsitov cheloveka i kolichestvo iader v nikh.

The study of isolated cardiomyocytes after alkaline dissociation allowed to reveal an individual variability of the absolute number and average volume of cells, as well as characteristics of these indices in the left and right ventricle myocardia of the dead adult patients' hearts. On the basis of the analysis of these indices and of other parameters of isolated cardiomyocytes, a possibility of hyperplasia of nuclei and of muscle cells themselves during their hypertrophy is discussed.

[Characteristics of isolated cardiomyocytes in concentric and eccentric hypertrophy of the human heart ventricle]. / Kharakteristika izolirovannykh kardiomiotsitov pri kontsentricheskoi i ékstsentricheskoi gipertrofii zheludochkov serdtsa cheloveka.

Alkaline dissociation of cardiomyocytes was used for investigation of concentric and eccentric myocardial hypertrophy in 8 deceased patients with carions ventricular myocardial mass. For both ventricles and forms of hypertrophy the length, diameter and volume of the cells were found increased, the increase being proportional for the left ventricle (except the volume) and gross for linear enlargement of the right ventricle in eccentric hypertrophy. Absolute number of cardiomyocytes reached maximum in concentric left ventricular hypertrophy showing the same values with normal-mass ventricles in eccentric hypertrophy.

[GABA reuptake by rat brain slices in hypokinesia and under the influence of cinnarizine and flunarizine]. / Obratnyi zakhvat GAMK srezami golovnogo mozga krys v usloviiakh gipokinezii i pod vliianiem tsinnarizina i flunarizina.

Studies showed that 15-day restriction of motor activity inhibits the reuptake of GABA by sections of the rat brain cortex and hypothalamus. In prolonged intraperitoneal injection of 10 mg/kg cinnarizine in hyperkinesia, further inhibition of this process in hypothalamic sections is encountered on the 15th days. Flunarizin (1 mg/kg) administered in a like manner has no significant effect on GABA reuptake. A course of GABA injections in a dose of 5 mg/kg improves in rats with restricted motor activity the local blood flow in the frontal lobe of the brain.

[Case of the transmission of the rat trypanosome by lice]. / Sluchai peredachi krysinoi tripanosomy vshami.

Data are given on the laboratory spontaneous occurrence of trypanosomiasis in young rats. It was demonstrated that the louse Polyplax spinulosa is the main mechanical vector of Trypanosoma lewisi. Unlike the case of the real host, the flea, the trypanosomes do not undergo the whole developmental cycle in the louse.

[Uptake and K+-evoked release of 3H-norepinephrine in the mesodiencephalic synaptosomes of albino rats during aging. Role of N-acetyl-L-aspartic acid]. / Zakhvat i K+-vyzvannoe vysvobozhdenie 3H-noradrenalina v mezodiéntsefal'nykh sinaptosomakh belykh krys pri starenii. Rol' N-atsetil-L-asparaginovoi kisloty.

The uptake and K(+)-evoked (40 mM) release of 3H-norepinephrine (3H-NE) in mesodiencephalic synaptosomes of adult and senescent rats and the effect of N-acetylaspartic acid (NAA) on these processes have been studied. It has been shown that the uptake of 3H-NE by old rats is reduced considerably. The K(+)-evoked release of 3H-NE from rats synaptosomes is significantly decreased in aged rats. In the presence of 10(-4)-3.10(-3) M NAA the uptake of 3H-NE by adult and senescent rats synaptosomes remains unchanged. In these concentrations NAA inhibits the K(+)-evoked release of 3H-NE from synaptosomes of adult rats, but it exerts no effect on this process in senescent rats.

The number and some other characteristics of isolated human ventricular cardiomyocytes under pathological conditions.

Using a modified method for alkalic dissociation, isolated ventricular cardiomyocytes were obtained from eight patients who had died of different diseases. The absolute number of cardiomyocytes, counted in the Fuchs-Rosenthal chamber, ranged between 1.10 x 10(9) and 3.25 x 10(9) in the left ventricle, and between 0.58 x 10(9) and 1.42 x 10(9) in the right ventricle depending on myocardial mass. Mean volume of cells ranged between 75 x 10(3) and 344 x 10(3) microns3, and the content of polynuclear, predominantly binucleated, cardiomyocytes amounted to 14 to 49%. An increase in ventricular myocardium mass was associated with an increase in cardiomyocyte volume. A negative correlation was demonstrated between the absolute number of cardiomyocytes on the one hand, and their mean volume and proportion of polynuclear cells on the other.

[Effect of gamma-aminobutyric acid on the concentration of noradrenaline in the synaptosoma fraction of the meso-diencephalic region of rat brain]. / Deistvie gamma-aminomaslianoi kisloty na soderzhanie noradrenolina v sinaptosomal'noi fraktsii mezo-diéntsefalicheskoi oblasti mozga krys.

We had previously shown [1, 2, 3, 4] that intraperitoneal administrations of 5 mg/kg amounts of gamma-aminobutyric acid (GABA) lower norepinephrine (NE) level of rat brain, this effect being most pronounced in the hypothalamic region. Subsequent studies showed that GABA increased normetanephrine level in iproniazid pretreated rats (II) and decreased NE content of crude mitochondrial fractions (12). These data implied changes in NE content of nerve endings. The results of the present study indicate that the NE content of the synaptosomal fraction of the mesodiencephalic region of GABA treated rats is significantly lower than that of untreated animals. This is a further confirmation of our previous results favouring a release of NE from nerve endings following the administration of GABA.

[Role of Na and Cl ions in retaining noradrenaline and serotonin in the meso-diencephalic region of the rat brain and in the action of gamma-aminobutyric acid on that process]. / Znachenie ionov Na i Cl v uderzhivanii noradrenalina i serotonina v mezo-díentsefalicheskoi oblasti mozga krys i v deistvii gamma-aminomaslianoi kisloty na étot

It has been previously reported from this laboratory that CABA affects the retention of norepinephrine (NE) and serotonin (5-HT) in rat brain tissue [2, 3, 4]. The addition of GABA (100 mug/ml) to the incubation medium enhances significantly the loss of NE from slices while the loss of 5-HT is, on the contrary, significantly smaller than that observed from slices incubated parallely for the same period. It has also been shown that this effect is observed only in a balanced ionic medium [1]. With the purpose of finding out the importance of Na+ and Cl- ions in the storage of monoamines and in the effect of GABA on this process in the present report we studied the effect of GABA on the loss of NE and 5-HT from slices of rat mesodiencephalic region incubated in media free of Na+ and Cl- ions. The effect of GABA on Na+, K+-ATP-ase activity, an enzyme involved in the active transport of monoamines, was also studied. The results obtained indicate that loss of both NE and 5-HT from slices was significantly enhanced in a Na+-free medium and that on addition of GABA (100 mug/ml) to such a medium no significant changes GABA were noted. In a Cl--free medium loss of NE from slices was enhanced while that of 5-HT was not affected. When GABA was added to such a medium the usual pattern so far observed in our experiments, i.e. an enhancement in the loss of NE from slices, was found to be reversed. The pronounced decrease of NE observed in a Cl--free medium was found to be partially checked by the addition of GABA, the difference observed being statistically significant. Thus, in a Cl--free medium GABA seems to display an effect on NE storage opposite to that observed in a normal medium. Incubation in a Cl--free medium did not induce any noticeable change in the retention of 5-HT in slices. However, when GABA was added to slices incubated in a Cl--free medium, it no more displayed its usual effect, i.e. it did not inhibit the loss of 5-HT from slices. Under the given experimental conditions, GABA added to a balanced ionic medium did not effect Na+,K+-ATP-ase activity. This is in good agreement with previous results from our laboratory [4] where GABA was shown to have no effect on the uptake of NE and 5-HT by slices of rat brain, an active, carrier-mediated process coupled with Na+,K+-ATP-ase activity.