Relationship of Structural and Tissue Components of Full-Layer Skin Wound and Mathematical Modeling of the Healing Process.

We studied the relationship between structural components of the wound (scab, leukocyte shaft, newly formed epithelium, and granulation tissue) and tissue components (epithelial and connective tissue) during spontaneous healing of skin wounds in rats. The regenerate structures were evaluated by microscopic morphometry. The number of vessels in 10 fields of view was calculated (at ×600), the dimensions of newly formed regenerate structures were determined: height of the scab, leukocyte shaft, granulation tissue, the border zone of the epithelium, and the length of the epithelial wedge. For the studied morphometric parameters, regression models of changes in the parameters of the regenerating wound were created depending on the term of the reparative process (days 7 and 14). The correlation analysis of the morphometric parameters of the regenerating wound revealed bilateral strong (direct and inverse) correlations in pairs. Most of the identified dependencies were linear and the changes in the number of vessels in the granulation tissue fit the quadratic regression law. The regularities observed by us during spontaneous healing of full-layer skin defects can be considered as control values for comparison with reparation of similar wounds under conditions of stimulation.

[Antitumor and antiproliferative action of the steroidal cytostatic antiestrogen cytestrol acetate on hormone-dependent tumor models].

Cytestrole acetate (CA), in the structure of which the steroidal antiestrogen component is associated with bis-ß-cloroethylamino group, exhibits a strong cytotoxic activity against hormone-dependent cancer cell lines (CaOV, HeLa, MCF-7). In doxorubicin-resistant MCF-7 cells, CA potentiates the cytotoxic effect of etoposide and doxorubicin, and the IC50 for CA in these cells is 40 times lower than that for tamoxifen (TAM). In transplantable mice breast adenocarcinoma Ca-755, the therapeutic CA dose is 25 mg/kg when administered subcutaneously in oil solution for 5 days. On the DMBA-induced mammary tumors in rats, CA injected subcutaneously led to partial regressions 4 weeks after treatment in 75% of test rats, whereas TAM produced this effect in 43% of rats. Among various drug forms of CA, the most active were oil solution of CA in gelatin capsules for oral use and liposomal emulsion for intravenous administration, since these forms exhibited the highest values of Ca-755 tumor growth inhibition index (TGI = 97 - 98%).

[Redox-dependent ferric oxide nanoparticles loaded with doxorubicin and their influence on the functions of mitochondria].

The spectral, fluorescent and functional properties of ferric oxide and ferric hydroxide nanoparticles loaded with doxorubicin and stabilized with citric acid or lysine were studied in comparison with free doxorubicin. Their effect on the opening of calcium-induced mitochondrial pore and the possibility of the controlled release of doxorubicin under the influence of redox stimuli were investigated. The data show that the effect of nanoparticles on mitochondria depends on the type of a stabilizer. The spectral and fluorescence methods used allow us to estimate the presence or absence of free doxorubicin in solution of nanoparticles and the:concentration of bound doxorubicin. It is shown that the dithiotreitol and glutathione increase the amplitude of absorption and fluorescence of doxorubicin during incubation with nanoparticles. It is assumed that this effect may be associated with the reduction of the oxidized iron by thiols with subsequent release of doxorubicin.

[Pancreas reaction in dogs with impaired glucose tolerance to the physical loads of different intensity].

The aim of this work was to study the structure of pancreas in the dogs with impaired glucose tolerance exposed to single short and repeated physical loads. The experiments were conducted in 26 male dogs aged 2-4 years, 10 animals formed the control group. The exposure was modeled as a run on treadmill with the velocity of 15 km/hr. The structure of the pancreas was examined using histological, electron microscopic and morphometric methods. Single short-term physical load was accompanied by predominantly compensatory and adaptive changes in both exocrine and endocrine parts of the gland. Among these changes the most significant were the stimulation and some small disturbances of a local blood flow in parainsular areas of the pancreatic endocrine part, as well as some signs indicative of the stimulation of insulin and pancreatic enzyme synthesis and secretion. After repeated physical c loads, the pronounced disturbances of the microcirculation were found in the exocrine part of the gland, which were accompanied by insulinocyte edema and local destruction. It is concluded that in the animals with impaired glucose tolerance, the repeated physical c loads of even moderate intensity could be the factor provoking tissue damage.

[Skin melanocytes].

This review summarises current data on the origin, structure and functions of skin melanocytes. Methods of melanocyte identification, including the immunohistochemical ones, are presented. Cellular mechanisms of melanosome formation, their transfer from melanocytes to keratinocytes and the problems of melanogenesis control in humans, are discussed.

Combined effect of bis-beta-chloroethylamine estrogen derivatives and doxorubicin on proliferation of sensitive and resistant MCF-7 cells.

The sensitivity of normal (MCF-7/WT) and doxorubicin-resistant (MCF-7/R) breast cancer cells to the antiproliferative effect of ethynylestradiol 11alpha-derivatives with the cytostatic residue in the 3-position of the steroid ring (antiestrogen cytostatics) was studied by evaluating cell viability using methylthiazole tetrazolium staining. The antiproliferative effects of these agents on cell lines in the presence of doxorubicin were compared. Antiestrogen cytostatics produced weaker cytostatic effect on MCF-7/WT cells, but more potent cytostatic effect on MCF-7/WT cells compared to those of doxorubicin. Moreover, administration of these agents in combination with doxorubicin more significantly suppressed proliferation of tumor cells. Accumulation and efflux of cytostatic doxorubicin in MCF-7/R cells were studied in the presence and absence of antiestrogen cytostatic Po716. Confocal laser microscopy showed that doxorubicin accumulation in MCF-7/R cells in the absence of Po716 took 20 min, while in the presence of antiestrogen cytostatic this process took 5 min. The rate of doxorubicin transport from tumor cells was much lower in the presence of the test antiestrogen cytostatic. Our results suggest that antiestrogen cytostatics increase the sensitivity of resistant MCF-7/R cells to doxorubicin by modulating the mechanisms of multidrug resistance of tumor cells.

Regeneration of the rat spinal cord after thoracic segmentectomy: growth and restoration of nerve conductors.

The results presented in our previous report (Morfologiya, 127, No. 2 (2005)) provided evidence that consolidation of the spinal cord (SC) after thoracic segmentectomy in rats occurs as a result of the formation of a connective tissue scar, which is quicker when the defect is filled with collagen gel. The present report describes analysis of semithin sections and transmission electron microscopy studies demonstrating that regenerating nerve conductors traverse connective tissue in structures whose organization is identical to that of peripheral nerves. In the zone of SC rarefaction caudal to the trauma site, myelination of growing axons is mediated by glial cells without the formation of nerve trunks. Large numbers of fine regenerating conductors were seen at the sites of degenerated myelin fibers in the fasciculi of the white matter in the lumbar segments of the SC.

[Electron-tomographic analysis of the Golgi complex structure in cultured cells].

Study of the Golgi complex (GC) in cultured NRK cells using improved method of sample preparation for electron tomography (ET) enabled to detect more fine details of GC structure. With the application of quantitative ET, no numerous vesicles were detected around GC, while most of stacks constantly contained intercisternal connections. It was demonstrated that vesicular-tubular clusters, which serve as the exit sites from endoplasmic reticulum, were composed of two domains: varicose tubules with sparse COPII-coated vesicles and a network of smooth tubules. The data obtained argue against the models of transport, which consider the vesicles as the main or necessary membranous carriers. On the contrary, continuous tubular connections seem to play an important role in traffic joining secretory pathway regions.

[How to measure structures, or new stereology: III. Stereology and electron microscopy].

This review describes modern stereological approaches and methods for estimation of subcellular structures dimensions. These estimators could be used for determination of number- and volume-weighted parameters of particle size. Very often they do not require the application of the disector at the first stage of sampling of images. Additionally, the modified version of the rotator for point counting is demonstrated, which significantly accelerates the morphometric procedure.

Regeneration of the rat spinal cord after thoracic segmentectomy: restoration of the anatomical integrity of the spinal cord.

Segmentectomy of the spinal cord (SC) was performed in 28 rats at the level of the tenth thoracic vertebra. Scar formation at the operation site was studied, along with the completeness of the anatomical integrity of the SC, in control animals (group 1) and after filling of the defect with the neural matrix Spherogel (group 2) and with Spherogel containing embryonic nerve cells (group 3). The defect in the SC in animals of the control group was filled with fibrin masses by 1-2 weeks, while connective tissues scars were already formed by this time in rats of experimental groups 2 and 3. By 10-11 weeks, these animals showed partial recovery of movement in the three lower limb joints. The scar tissue and adjacent zones of the SC showed large quantities of regenerating fine myelinated nerve fibers. These were clearly evident in the zones of the cranial and caudal margins, to the extent of the appearance of typical SC tissue. In preparations obtained from control animals, fine myelinated fibers were noted in the immediate vicinity of SC substance, while nerve fibers were few in number in scar tissue and the cellular bands of the transitional zone.

[Spinal cord regeneration in rats after thoracic segmentectomy: growth and regeneration of nerve fibers].

As it was described in a previous paper (Morphology, 2005, v.127, Iss. 2), spinal cord (SC) consolidation after thoracic segmentectomy in rats took place via connective tissue scar formation in the area of trauma, which was accelerated when SC defect was filled with by the collagen gel (Spherogel). In this paper, on the basis of semithin section analysis and transmission electron microscopic study, it was shown that regenerating nerve fibers crossed the connective tissue within the formations, which were structurally identical to peripheral nerves. In the zones of rarified SC substance, caudally to the site of trauma, myelination of growing axons was realized by glial cells without the formation of the nerve truncs. In the white matter, within the fasciculi of SC lumbar segments, multiple thin regenerating fibers were seen in the area of degenerated myelinated nerve fibers.

[Evolutionary approach to the understanding of structural and functional organization of Golgi apparatus].

This article analyzes the literature data related to the discussion of the main models of intracellular protein transport, including vesicular and cistern maturation-progression models. The existence of an important Golgi complex (GC) component--continuous tubular structures--is emphasized and their possible participation in the intracellular transport is discussed. A brief review is presented, describing the peculiarities of intracellular traffic in eukaryotic species belonging to different stages along the evolutionary process. The evidence suggests that in higher eukaryotes, the dynamic membranous GC system was formed on the basis of tubular networks that performs protein sorting and selective protein transport.

[Spinal cord regeneration in rats after thoracic segmentectomy: restoration of the anatomical integrity of the spinal cord].

Spinal cord (SC) segmentectomy was performed at ThX level in 28 rats. The scar formation in place of surgery and the degree of restoration of anatomical integrity were studied in control rats (group I) and in rats, in which SC defect was replaced by either Spherogel neuromatrix (group II) or Spherogel containing dispersed embryonic nerve cells (group II). While in group I rats by weeks 1-2 SC defect was filled with fibrin masses, in rats of experimental groups II and III the formation of connective tissue scar was found by the same time. By weeks 10-11 these animals demonstrated partial restoration of motion in three joints of the hindlimb. In the scar tissue and in adjacent SC zones numerous regenerating thin myelinated nerve fibers were found. They were clearly demonstrated in the zones of cranial and caudal borders along the whole distance until the appearance of typical tissue of SC. In slides from the animals of control group, thin myelinated nerve fibers were found only in close proximity to SC substance, while in the scar tissue and in the cellular bands of the intermediate zone nerve fibers were scarce.

[How to measure the structures, or new stereology. II. Methods of stereological estimation of the absolute dimensions of cell structures in light microscopy].

This review describes modern stereological estimators used for the counting of histological structures and their parameters determination at the light microscopic level. All of these estimators, as a rule, require the preliminary application of a disector for the sampling of images. Nucleator and rotator not only allow unbiased determination of structures absolute dimensions, but also help to save the time used for these operations. In the last years, these stereological estimators are being increasingly used in clinical practice and in electron microscopical analysis.

[Role of pericytes in mechanism of vessel neovascularisation in the regenerating connective tissue]. / Rol' peritsitov v mekhanizme novoobrazovaniia sosudov regeneriruiushchei soedinitel'noi tkani.

This work presents the data of electron microscopic study of cellular interrelations in the process of capillary growth in the regenerating connective tissue. The study was performed in 28 albino rats which have been implanted with different polymer nets in the muscle defects of anterior abdominal wall. A combined activation of both endothelial cells (EC) and pericytes was demonstrated during the earliest stages of angiogenesis. The pericytes, but not EC, were shown to form the frontal zone of growing capillary sprout by the synthesis of the extracellular matrix components ahead of migrating EC. The possible role of pericytes in the control of capillary development and growth in the regenerating tissue is discussed.

Comparative ultrastructural study of the effect of imidazo-benzimidazole derivatives RU-185 and RU-254 on the development of microcirculatory disturbances in the skin under conditions of reduced blood flow.

In rats with experimental partial ischemia of the skin fold the state of microvessels and surrounding skin was studied by electron microscopy under control conditions and after treatment with imidazo-benzimidazole derivatives RU-185 and RU-254. RU-185 was more potent than RU-254 in preventing the development of microcirculatory disturbances and altered permeability of capillary walls.

[Liver fatty degeneration and chronic hepatitis HCV]. / Zhirovaia distrofiia gepatotsitov i khronicheskii HCV-gepatit.

Fatty degeneration in HCV-hepatitis is, according to the authors' data, an active process determining progression of liver fibrosis. This allow to formulate new approaches to treatment of chronic HCV-hepatitis.

[Ultrastructural changes of veins in several variants of cryopreservation]. / Ul'trastrukturnye izmeneniia ven pri razlichnykh variantakh kriokonservatsii.

The findings of ultrastructural analysis demonstrated essential changes in connective tissue cells and noncellular elements of veins after their cryopreservation at -50 degrees C and -196 degrees C. Contraction and round-up of endotheliocytes, disruption of their connections with basement membrane leading to subendothelial space widening, cytoplasm vacuolization and focal destruction of luminal plasmalemma are typical and general changes caused by cryopreservation. Dystrophy of different grades developed in connective tissues of media and adventitia. Deeper freezing negatively affects structural integrity of venous tissues. After the use of conserving solutions (Eurocollins and Scientific Research Institute of Traumatology and Orthopaedics) necrotized endotheliocytes were absent and endothelial lining was preserved in major part of the vein surface studied even following its deep freezing which supports the conclusion on the cryoprotective effect of the solutions.