Inside and outside of virus-like particles HBc and HBc/4M2e: A comprehensive study of the structure

Hepatitis B virus core antigen (HBc) with the insertion of four external domains of the influenza A M2 protein (HBc/4M2e) form virus-like particles whose structure was studied using a combination of molecular modeling and cryo-electron microscopy (cryo-EM). It was also shown that self-assembling of the particles occurs inside bacterial cells, but despite the big inner volume of the core shell particle, purified HBc/4M2e contain an insignificant amount of bacterial proteins. It was shown that a fragment of the M2e corresponding to 4M2e insertion is prone to formation of amyloid-like fibrils. However, as the part of the immunodominant loop, M2e insertion does not show a tendency to intermolecular interaction. A full-atomic HBc-4M2e model with the resolution of about 3 Å (3.13 Å for particles of Т = 4 symmetry, 3.7 Å for particles of Т = 3 symmetry) was obtained by molecular modeling methods based on cryo-EM data.

A Genome of Temperate Enterococcus Bacteriophage Placed in a Space of Pooled Viral Dark Matter Sequences

In the human gut, temperate bacteriophages interact with bacteria through predation and horizontal gene transfer. Relying on taxonomic data, metagenomic studies have associated shifts in phage abundance with a number of human diseases. The temperate bacteriophage VEsP-1 with siphovirus morphology was isolated from a sample of river water using Enterococcus faecalis as a host. Starting from the whole genome sequence of VEsP-1, we retrieved related phage genomes in blastp searches of the tail protein and large terminase sequences, and blastn searches of the whole genome sequences, with matches compiled from several different databases, and visualized a part of viral dark matter sequence space. The genome network and phylogenomic analyses resulted in the proposal of a novel genus "Vespunovirus", consisting of temperate, mainly metagenomic phages infecting Enterococcus spp.

Old dog, new tricks: Influenza A virus NS1 and in vitro fibrillogenesis

The influenza NS1 protein is involved in suppression of the host immune response. Recently, there is growing evidence that prion-like protein aggregation plays an important role in cellular signaling and immune responses. In this work, we obtained a recombinant, influenza A NS1 protein and showed that it is able to form amyloid-like fibrils in vitro. Using proteolysis and subsequent mass spectrometry, we showed that regions resistant to protease hydrolysis highly differ between the native NS1 form (NS1-N) and fibrillar form (NS1-F); this indicates that significant structural changes occur during fibril formation. We also found a protein fragment that is capable of inducing the process of fibrillogenesis at 37 °C. The discovery of the ability of NS1 to form amyloid-like fibrils may be relevant to uncovering relationships between influenza A infection and modulation of the immune response.

Cold and distant: structural features of the nucleoprotein complex of a cold-adapted influenza A virus strain

Two influenza A nucleoprotein variants (wild-type: G102R; and mutant: G102R and E292G) were studied with regard to macro-molecular interactions in oligomeric form (24-mers). The E292G mutation has been previously shown to provide cold adaptation. Molecular dynamics simulations of these complexes and trajectory analysis showed that the most significant difference between the obtained models was distance between nucleoprotein complex strands. The isolated complexes of two ribonucleoprotein variants were characterized by transmission electron microscopy and differential scanning fluorimetry (DSF). Presence of the E292G substitution was shown by DSF to affect nucleoprotein complex melting temperature. In the filament interface peptide model, it was shown that the peptide corresponding in primary structure to the wild-type NP (SGYDFEREGYS) is prone to temperature-dependent self-association, unlike the peptide corresponding to E292G substitution (SGYDFGREGYS). It was also shown that the SGYDFEREGYS peptide is capable of interacting with a monomeric nucleoprotein (wild type); this interaction's equilibrium dissociation constant is five orders of magnitude lower than for the SGYDFGREGYS peptide. Using small-angle neutron scattering (SANS), the supramolecular structures of isolated complexes of these proteins were studied at temperatures of 15, 32, and 37 °C. SANS data show that the structures of the studied complexes at elevated temperature differ from the rod-like particle model and react differently to temperature changes. The data suggest that the mechanism behind cold adaptation with E292G is associated with a weakening of the interaction between strands of the ribonucleoprotein complex and, as a result, the appearance of inter-chain interface flexibility necessary for complex function at low temperature.Communicated by Ramaswamy H. Sarma.

[Pneumocephaly: an expert assessment in determining the severity of harm to health]

The purpose of the work is the analysis of etiology and pathogenesis of pneumocephaly in various injuries, diseases and pathological conditions for the reasonable determination of the severity of health damage during forensic medical examinations. The analysis of literature data on the causes and mechanisms of pneumocephaly is given. Attention is paid to the assessment of pneumocephaly in determining the health damage in patients with traumatic brain injury or if it is suspected. It is proposed to consider pneumocephaly as an indirect sign of a skull fracture. In case of pneumocephaly, a radiologically confirmed fracture is necessary to justify serious health damage. The medical documents of the victim should be examined to exclude concomitant diseases and pathological conditions that can lead to pneumocephaly.

Meglumine acridone acetate, the ionic salt of CMA and N-methylglucamine, induces apoptosis in human PBMCs via the mitochondrial pathway

Meglumine acridone acetate (MA) is used in Russia for the treatment of influenza and other acute respiratory viral infections. It was assumed, until recently, that its antiviral effect was associated with its potential ability to induce type I interferon. Advanced studies, however, have shown the failure of 10-carboxymethyl-9-acridanone (CMA) to activate human STING. As such, MA’s antiviral properties are still undergoing clarification. To gain insight into MA’s mechanisms of action, we carried out RNA-sequencing analysis of global transcriptomes in MA-treated (MA+) human peripheral blood mononuclear cells (PBMCs). In response to treatment, approximately 1,223 genes were found to be differentially expressed, among which 464 and 759 were identified as either up- or down-regulated, respectively. To clarify the cellular and molecular processes taking place in MA+ cells, we performed a functional analysis of those genes. We have shown that evident MA subcellular localizations are: at the nuclear envelope; inside the nucleus; and diffusely in perinuclear cytoplasm. Postulating that MA may be a nuclear receptor agonist, we carried out docking simulations with PPARα and RORα ligand binding domains including prediction and molecular dynamics-based analysis of potential MA binding poses. Finally, we confirmed that MA treatment enhanced nuclear apoptosis in human PBMCs. The research presented here, in our view, indicates that: (i) MA activity is mediated by nuclear receptors; (ii) MA is a possible PPARα and/or RORα agonist; (iii) MA has an immunosuppressive effect; and (iv) MA induces apoptosis through the mitochondrial signaling pathway.

Inhibition of influenza A virus by mixed siRNAs, targeting the PA, NP, and NS genes, delivered by hybrid microcarriers

In the present study, a highly effective carrier system has been developed for the delivery of antiviral siRNA mixtures. The developed hybrid microcarriers, made of biodegradable polymers and SiO₂ nanostructures, more efficiently mediate cellular uptake of siRNA than commercially available liposome-based reagents and polyethyleneimine (PEI); they also demonstrate low in vitro toxicity and protection of siRNA from RNase degradation. A series of siRNA designs (targeting the most conserved regions of three influenza A virus (IAV) genes: NP, NS, and PA) were screened in vitro using RT-qPCR, ELISA analysis, and hemagglutination assay. Based on the results of screening, the three most effective siRNAs (PA-1630, NP-717, and NS-777) were selected for in situ encapsulation into hybrid microcarriers. It was revealed that pre-treatment of cells with a mixture of PA-1630, NP-717, and NS-777 siRNAs, delivered by hybrid microcarriers, provided stronger inhibition of viral M1 mRNA expression and control of NP protein level, after viral infection, than single pre-treatment by any of three encapsulated siRNAs used in the study. Moreover, the effective inhibition of replication in several IAV subtypes (H1N1, H1N1pdm, H5N2, and H7N9) using a cocktail of the three selected siRNAs, delivered by our hybrid capsules to the cells, was achieved. In conclusion, we have developed a proof-of-principle which shows that our hybrid microcarrier technology (utilizing a therapeutic siRNA cocktail) may represent a promising approach in anti-influenza therapy.

COMPARISON OF INFLUENZA A VIRUS INHIBITION IN VITRO BY SIRNA COMPLEXES WITH CHITOSAN DERIVATIVES, POLYETHYLENEIMINE AND HYBRID POLYARGININE-INORGANIC MICROCAPSULES

Anti-influenza drugs and vaccines have a limited effect due to the high mutation rate of virus genome. The direct impact on the conservative virus genome regions should significantly improve therapeutic effectiveness. The RNA interference mechanism (RNAi) is one of the modern approaches used to solve this problem. In this work, we have investigated the antiviral activity of small interfering RNA (siRNA) against the influenza A/PR/8/34 (H1N1), targeting conserved regions of NP and PA. Polycations were used for intracellular siRNA delivery: chitosan's derivatives (methylglycol and quaternized chitosan), polyethyleneimine, lipofectamine, and hybrid organic/non-organic microcapsules. A comparative study of these delivery systems with fluorescent labeled siRNA was conducted. The antiviral activity of three small interfering RNAs targeting the NP (NP-717, NP-1496) and PA (PA-1630) influenza A viruses genes was demonstrated, depending on the chosen carrier. The most effective intracellular delivery and antiviral activity were observed for hybrid microcapsules.

[Effects of the of renal warm ischemia time on the recovery of filtration function in the experiment]

AIM

To investigate experimentally ultrastructural and biochemical signs of acute injury to the renal parenchyma after warm renal ischemia of various duration and subsequent reperfusion.

MATERIALS AND METHODS

The experiments were performed on 44 healthy conventional female rabbits of the "Chinchilla" breed weighted 2.6-2.7 kg, which were divided into four groups. In the first, control, group included pseudo-operated animals. In the remaining three groups, an experimental model of warm ischemia of renal tissue was created, followed by a 60-minute reperfusion. The renal warm ischemia time was 30, 60 and 90 minutes in the 2nd, 3rd and 4th groups, respectively. Electron microscopy was used to study ultrastructural disturbances of the renal parenchyma. Biochemical signs of acute kidney damage were detected by measuring the following blood serum and/or urine analytes: NGAL, cystatin C, KIM-1, L-FABP, interleukin-18. The glomerular filtration was evaluated by creatinine clearance, which was determined on days 1, 5, 7, 14, 21 and 35 of follow-up.

RESULTS

A 30-minute renal warm ischemia followed by a 60-minute reperfusion induced swelling and edema of the brush membrane, vacuolation of the cytoplasm of the endothelial cells of the proximal tubules, and microvilli restructuring. The observed disorders were reversible, and the epithelial cells retained their viability. After 60 minutes of ischemia and 60 minutes of reperfusion, the observed changes in the ultrastructure of the epithelial cells were much more pronounced, some of the epithelial cells were in a state of apoptosis. 90 min of ischemia and 60 min of reperfusion resulted in electron-microscopic signs of the mass cellular death of the tubular epithelium. Concentration in serum and/or biochemical urine markers of acute renal damage increased sharply after ischemic-reperfusion injury. Restoration of indicators was observed only in cases when the renal warm ischemia time did not exceed 60 minutes. The decrease in creatinine clearance occurred in the first 24 hours after the intervention, lasting not less than two weeks after a 30-minute warm ischemia, at least 3 weeks after a 60-minute warm ischemia and continued more than a month after a 90-minute renal artery occlusion.

CONCLUSION

Intraoperative warm ischemia and subsequent reperfusion are the actual reasons for the alteration of the ultrastructure of the renal tissue and the impairment of the filtration function. The severity of the disorders depends on the duration of the damaging factors. After a 30-60-minute ischemia, the structural and functional changes in the renal tissue are reversible. The mass death of nephrocytes-effectors is possible only after warm renal ischemia longer than 60 min.

Telocytes in the human sinoatrial node

The sinoatrial node (SAN) is composed mostly of pacemaker, transitional and Purkinje‐like cells. Pacemaker cells, especially in the centre of the SAN, are surrounded by dense fibrous tissue and do not have any contact with transitional cells. We hypothesize that the SAN contains telocytes that have contacts with pacemaker cells and contractile myocardium. Immunohistochemistry using antibodies against HCN4 and antibody combinations against CD34 and HCN4 was carried out on 12 specimens. Confocal laser scanning microscopy (CLSM) with two mixtures of primary antibodies, namely CD34/S100 and vimentin/S100, was performed in three cases. In two cases, CLSM was carried out with CD117 antibody. Specimens for electron microscopy and immunocytochemistry with HCN4 immunogold labelling were taken from another three patients. In our study, we found cells with the immunophenotype of telocytes in the SAN. There were twice as many of these cells in the centre of the SAN as in the periphery (20.3 ± 4.8 versus 10.8 ± 4.4 per high‐power field). They had close contact with pacemaker cells and contractile cardiomyocytes and expressed HCN4. The ultrastructural characteristics of these cells are identical to those of telocytes observed earlier in other organs. Our study provides evidence that telocytes are present in the SAN.

In vitro toxicity of FemOn, FemOn-SiO2 composite, and SiO2-FemOn core-shell magnetic nanoparticles

Over the last decade, magnetic iron oxide nanoparticles (IONPs) have drawn much attention for their potential biomedical applications. However, serious in vitro and in vivo safety concerns continue to exist. In this study, the effects of uncoated, FemOn-SiO2 composite flake-like, and SiO2-FemOn core-shell IONPs on cell viability, function, and morphology were tested 48 h postincubation in human umbilical vein endothelial cell culture. Cell viability and apoptosis/necrosis rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and annexin V-phycoerythrin kit, respectively. Cell morphology was evaluated using bright-field microscopy and forward and lateral light scattering profiles obtained with flow cytometry analysis. All tested IONP types were used at three different doses, that is, 0.7, 7.0, and 70.0 μg. Dose-dependent changes in cell morphology, viability, and apoptosis rate were shown. At higher doses, all types of IONPs caused formation of binucleated cells suggesting impaired cytokinesis. FemOn-SiO2 composite flake-like and SiO2-FemOn core-shell IONPs were characterized by similar profile of cytotoxicity, whereas bare IONPs were shown to be less toxic. The presence of either silica core or silica nanoflakes in composite IONPs can promote cytotoxic effects.

[The application of forensic medical knowledge for the reconstruction of historical events]

The objective of the present study was to summarize the results of many year investigations on the application of forensic medical methods and experience for the reconstruction of historical events including identification of the ancient Russian saints' hallows and statesmen's remains, elucidation of the genuine causes of death of the members of the Russian Imperial House of Romanovs based on the recently discovered archival materials, restoration of the character of the injuries suffered by Aleksander II, M.I. Kutuzov, P. Demidov, G. Gapon., and G. Rasputin, the attribution A.S. Pushkin's memorial belongings based on the biological traces, and the like.

A conservative mutant of a proteolytic fragment produced during fibril formation enhances fibrillogenesis

The fibrillogenesis of a peptide corresponding to residues 35-51 of human α-lactalbumin (¹GYDTQAIVENNESTEYG¹⁷) can be dramatically enhanced by the addition of a tetrapeptide TDYG homologous to its C-terminus (TEYG). Generation of spontaneous hydrolytic products similar to this peptide was demonstrated by mass-spectrometry analysis of GYDTQAIVENNESTEYG peptide solution components during fibrillogenesis. Possible mechanisms and roles of short peptides in protein metabolism are discussed.

[FUNCTIONAL LINK BETWEEN TRANSPORT PARAMETERS OF MDCK1 CELLS MONOLAYER AND THEIR ACTIN CYTOSKELETON ORGANIZATION]

On MDCK1 cell monolayer, dynamics of the spatial organization of actin cytoskeleton and dynamics of trans-epithelial electrical resistance (TEER) have been studied upon exposure of arginine-vasopressin (AVP) and protein-kinase A (PKA) activator forskolin. It has been found that exposure to these physiologically active compounds causes fibrillary actin depolymerization (both in apical and in basal cytoplasm) and, simultaneously, significant decrease in the cell monolayer trans-epithelial electrical resistance. TEER decrease indicates the stimulation of ions and water flow across the cell monolayer. In order to clarify pathways of movement of ions and water across MDCK monolayer, we have carried out an immunofluoresence study of claudin 1 and 2 localization in the tight junctions of MDCK ATCC cells (low TEER) and MDCK1 cells (high TEER). We have demonstrated that in the tight junctions of MDCK ATCC cells both claudin 1 and claudin 2 are present. In MDCK1 cells tight junctions, claudin 1 is localized and pore-forming claudin 2 is completely lacking. Under forskolin exposure to MDCK1 cells, no alterations in studied claudins distribution has been found. These data indicate that forskolin-induced TEER decrease is linked with alterations in trans-cellular, not in para-cellular, permeability of monolayer.

[Morphological features of the myometrium in connective tissue dysplasia in women with uterine inertia]

OBJECTIVE

to reveal the morphological features of the lower uterine segment myometrium in connective tissue dysplasia (CTD) in women with uterine inertia.

MATERIAL AND METHODS

Histological, immunohistochemical (with antibodies against collagen types I and III, matrix metalloproteinases 1 and 9 (MMR-1, MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1), fibronectin; fibulin-5, connexin-43), electron microscopic, and electron immunocytochemical studies with morphometry of myometrial fragments from 15 parturient women with CTD and uterine inertia (a study group) and those from 10 women without CTD (a control group).

RESULTS

The myometrium in CTD exhibited the decreased expression of connextin-43, fibulin-5, TIMP-1, collagens types I and III with collagen type III predominance and the unchanged levels of fibronectin and MMP-1 and MMP-9. Electron microscopy and immunocytochemistry showed fewer intercellular contacts and the dramatically lower expression of connexin-43 than in the control.

CONCLUSION

A set of found myometrial changes in women with uterine inertia is a manifestation of CTD.

Evidence of specialized tissue in human interatrial septum: histological, immunohistochemical and ultrastructural findings

Background

There is a paucity of information on structural organization of muscular bundles in the interatrial septum (IAS). The aim was to investigate histologic and ultrastructural organization of muscular bundles in human IAS, including fossa ovalis (FO) and flap valve.

Methods

Macroscopic and light microscopy evaluations of IAS were performed from postmortem studies of 40 patients. Twenty three IAS specimens underwent serial transverse sectioning, and 17 - longitudinal sectioning. The transverse sections from 10 patients were immunolabeled for HCN4, Caveolin3 and Connexin43. IAS specimens from 6 other patients underwent electron microscopy.

Results

In all IAS specimens sections the FO, its rims and the flap valve had muscle fibers consisting of working cardiac myocytes. Besides the typical cardiomyocytes there were unusual cells: tortuous and horseshoe-shaped intertangled myocytes, small and large rounded myocytes with pale cytoplasm. The cells were aggregated in a definite structure in 38 (95%) cases, which was surrounded by fibro-fatty tissue. The height of the structure on transverse sections positively correlated with age (P = 0.03) and AF history (P = 0.045). Immunohistochemistry showed positive staining of the cells for HCN4 and Caveolin3. Electron microscopy identified cells with characteristics similar to electrical conduction cells.

Conclusions

Specialized conduction cells in human IAS have been identified, specifically in the FO and its flap valve. The cells are aggregated in a structure, which is surrounded by fibrous and fatty tissue. Further investigations are warranted to explore electrophysiological characteristics of this structure.

[Influence of protamine on expression of tight junction proteins in Caco-2]

Action of polycation protein protamine on the expression of tight junction proteins (claudins-1, -2, -3 and occludin) which contribute to paracellular transport function was investigated on cellular models of tight (MDCK I cell line) and leaky (Caco-2 cell line) epithelium. The expression of claudins-1,-3 and occludin was observed in both cell lines by methods of immunocytochemistry. Influence of protamine (100 microg/ml; 30 min; apical) on fluorescence intensity of claudins-1, -3 was different in MDCK I and Caco-2 cells. Addition ofprotamine to the incubation medium of Caco-2 cells resulted in significant increase of claudin-3 expression by 45 % (p <0.01) in comparison with control, whereas claudin-1 and occludin expression did not alter. On the contrary, in MDCK I cells protamine induced the significant decrease ofclaudin-1 and -3 expression by 25 % (p <0.001) and 15 % (p < 0.01) respectively, whereas occludin expression did not alter. It was confirmed by the methods of confocal laser scanning microscopy that protamine alter the expression of claudins-1, -3 directly in the tight junctions. Our results suggest that charged chyme components may alter paracellular permeability of epithelium.

[Modeling of kidney collecting ducts function in the cell culture conditions]

Continuous cell lines originating from the kidney collecting duct represent a powerful tool for the modeling of water and ions reabsorbtion processes. Present review considers the basic methodical approaches being utilized to study vasopressin-induced water transport mechanisms in the cell culture conditions--microscopical methods, electrophysiological measurements, various ways of evaluation of water flow across the cell monolayer, transfections of native and mutant proteins, GFP-technology. The results of the highest significance for the understanding of collecting ducts function which were obtained with usage of these methods are analyzed in the review.

[Ultrastructure of coelomic epithelium and coelomocytes of intact and wounded starfish Asterias rubens L]

Samples of coelomic epithelium and coelomocytes suspension of intact and wounded starfishes Asterias rubens L. were analyzed by electron microcopy. It has been demonstrated that coelomic epithelium is composed of three types of cells: flagellar (approx. 60%), secretory (approx. 3%) and myoepithelial (approx. 37%). Flagellar and secretory cells form the apical surface of coelomic epithelium. Secretory cells are represented by two subtypes: granular and mucous secretory cells. Myoepithelial cells are located in the basal zone of the epithelium. Adjacent flagellar cells are separated by intercellular gaps of various size in 4-5% of cases. These gaps are apparently the lacunae left by the flagellar cells after their departure to the coelomic cavity. The morphological pattern of transition of coelomic epithelium flagellar cells to the coelomocytes has been characterized. No significant structural alterations in organization of the coelomic epithelium were revealed after moderate wounding used in the present study. Small round-shaped young coelomycytes (approx. 3%) and bigger mature coelomocytes (approx. 97%) were found in coelomocytes suspension. A flagellum was revealed on the surface of one of the young coelomocytes. Surface of the mature coelomocytes forms the processes of various size and structure; their cytoplasm contains lysosomes and fagocytic vacuoles of different size. After wounding, activation of coelomocytes was noted finding expression in the sharp rise in the number and the length of their surface filopodia, and in the multicellular aggregates formation. By the sum of the ultrastructural data, histogenesis of coelomocytes from the flagellar cells of the coelomic epithelium is supposed to be a process of cellular transdifferentiation.

[Arginin-vasopressin-induced alterations in the structure of MDCK cells]

Alterations in the structural organization of MDCK cells under arginin-vasopressin (AVP) action were studied by electron and fluorescent microscopy. Electron-microscopical evidence was obtained that MDCK cells within monolayer form structurally distinct apical and basolateral surfaces separated by well-developed intercellular contact zones. It was proved that AVP specifically bound to the receptors on the basolateral surface of the cells, and was internalized from the surface in 10-15 min. AVP action resulted in fragmentation of Golgi apparatus and swelling of Golgi cisterns caused by initiation of osmotic water flow across the monolayer. Significant depolymerization of cells actin cytoskeleton was revealed under AVP or forskolin (an adenylate cyclase activator) exposure. Functional role and regulatory mechanisms of described structural alterations are discussed.

[Principles of radiographic and endoscopic diagnosis of colorectal cancer]

An evaluation of the potential of X-ray and endoscopy diagnosis and preoperative staging of colorectal cancer has shown that the best results are to be obtained by their complex multistage and purposeful use. Timely examination heeding the specific features of either component will permit detection and identification of colorectal tumors according to International TNM classification.

[Potential of abdominal computed tomography and ultrasonography for the complex diagnosis of early gastric cancer]

The potential of computed tomography and ultrasonography in making complex diagnosis of "small forms" of early gastric cancer was demonstrated by evaluation of the data on examination of 116 patients and the pivotal role of the extent of intramural invasion was established. The semiotics of computed tomography and ultrasonography for intramural invasion and the sequence of X-ray and endoscopic procedures were developed.

[Potentialities of computed tomography in the diagnosis of hiatal hernia]

An analysis of the results of 98 studies has demonstrated the potentialities of X-ray computed tomography in the diagnosis of hiatal hernia (HH), provided the X-ray computed tomography (XCT) semiotics of HH. It has found that XCT may directly visualize and objectively evaluate anatomic structures, such as diagraphmatic crus and esophageal foremen. It has emphasized that when XCT of abdominal and thoracic organs is performed, it is necessary to include the areas of diagragmatic curs and esophageal foramen into the list of anatomic structures binding for visual assessment and characterization, which in combination with other studies will assist in the early diagnosis of hiatal hernia and eventually expand the potentialities of XCT to a greater extent.

[The necessity of complex use of radiation and endoscopic techniques in the differential diagnosis of gastric ulcerations]

The results of examination of 156 patients were used to consider whether radiation and endoscopic techniques might be used in the differential diagnosis of gastric ulcerations. The necessity of their complex use is shown. Evidence is provided for that the understanding of intramural changes at the site of ulceration should underlie the interpretation of visual changes in the gastric mucosa. An algorithm has been developed for the rational and effective use of radiation and endoscopic techniques in the differential diagnosis of gastric ulcerations. The algorithm is shown to be highly effective in the correct interpretation of the pattern of an identified ulceration (98.4% specificity). Ultrasound and computed tomographic semiotics of benign and malignant gastric ulcerations is presented.

[Capacities of transabdominal ultrasound study in the diagnosis of polyps of the stomach and colon]

The data obtained from studies of 84 patients with polyps of the stomach and colonic were used to consider the capacities of transabdominal and transrectal ultrasound studies and their diagnostic efficiency in the diagnosis of polyps of the stomach and colon. The ultrasound semiotics of polyps of the gastric and colon was described. A place of transabdominal ultrasound sonography (US) in the algorithm of radiation and endoscopic studies was established. This investigation led to the conclusion that transabdominal US, along with indirect diagnosis, permits solution of number of fundamental problems facing prior to polypectomy--these are primarily to define the nature of a detected polyp (epithelial and non-epithelial), based on an analysis of the laminar structure of the wall of an organ at the polyp base, a possible polyp malignancy and the degree of invasion into the depths of the gastric wall, as well as to detect a feeding vessel (in the CDC mode) and to predict the likelihood of possible complications. It is advisable to use transabdominal US in a complex of diagnostic techniques for polyps of the stomach and colon.

[Potentialities of transabdominal ultrasound study in the diagnosis of gastric peptic ulcer]

The results of examination in 44 patients with gastric peptic ulcer were used to consider the potentialities of a transabdominal ultrasound study in the diagnosis and monitoring of gastric ulcerations. The ultrasound semiotics of gastric ulcers is described in the paper. A role of transabdominal ultrasound study in the algorithm of radiation and instrumental studies of gastric ulcer is defined. The inclusion of this study into the algorithm of diagnosis and monitoring of gastric peptic ulcer will make it possible not only to diagnose gastric ulcerations better, but to follow up their cicatrization. It is expedient to include a transabdominal ultrasound study as one of the diagnostic techniques for gastric peptic ulcer.

[Use of complex indices of environmental air pollution for sanitary ranging of the territory of the South Administrative District of Moscow]

Whether complex indices of ambient air pollution can be used for sanitary ranging of primary facilities of the district was studied. The indices were calculated by using single air samples. The impact of "zero samples" on the results of calculation of the significance of differences in the single concentrations of individual chemical air pollutants was examined. The average annual concentrations of pollutants were calculated on the basis of average daily maximum allowable concentrations and the a-coefficient recommended by M. A. Pinigin. The database contains 20,000 definitions of the most hazardous chemical pollutants in the ambient air. Significant and insignificant values of chemical pollutants in single ambient air samples may be used in calculating complex indices as the rate of result coincidence was 80%, the suitability of insignificant values for ranging was confirmed in 81.25% of cases.

[Ultrastructure and elemental composition of frog bladder granular epithelial cells in normal state and upon stimulation of water transport]

Changes in the frog urinary bladder granular cell ultrastructure were analysed in parallel with those in element composition of these cells after induction of water transport across the urinary bladder wall. Two ultrastructural (ultrathin section and freeze-fracture) methods were used in addition to two methods of object preparation for electron microprobe analysis--freeze-drying and freeze-substitution. It has been shown that arginin-vasotocin stimulation of osmotic water flow across the urinary bladder wall causes certain morphological changes in the granular cells: decrease in electron density of the cytoplasm, depolymerization of the apical submembrane layer of actin microfilaments, increase in the number of sites of specific granules and apical membrane fusion, emergency of intramembrane particle aggregates in the apical membrane P-face. The quantitative electron microprobe analysis made it possible to reveal a statistically significant increase in sodium and calcium concentration and fall in that of potassium and chlorine in granular cells after water transport stimulation. A concentration gradient of sodium and potassium ions was seen to appear along the apical-basal axis in the cytoplasm of granular cells. Possible association between the obvious morphological transformations in granular cells and changes in their elemental composition has been discussed, in addition to some regulatory significance of calcium concentration increase in granular cells after arginin-vasotocin-induced osmotic water transport.

[Possibilities of radiologic methods (ultrasonography, computed tomography) in the preoperative evaluation of intramural invasion of gastric cancer]

By analyzing the findings in 72 patients with gastric cancer, the authors show the potentialities of noninvasive techniques of radiation diagnosis (transabdominal ultrasonography (USG) and X-ray computed tomography (CT) in the preoperative evaluation of the T-stage of gastric cancer. Ultrasound and computed tomographic semiotics of intramural invasion of gastric carcinoma is made. Ultrasonography was found to have the highest specificity in detecting early-stage gastric cancers prior to computed tomography. In the authors' opinion, a complex use of the data obtained by these techniques reveals the degree of invasion of gastric carcinoma and its extent with high precision. Transabdominal USG and CT should rank with the initial methods used for diagnosing gastric cancer. Transabdominal USG should be most expediently used as an initial technique of the above studies, by taking into account its wide accessibility, easiness-to-use, and lack of radiation load.

[Possibilities of CT and US in the diagnosis of colonic cancer]

The data of examination of 59 patients with colonic cancer were used to consider the potentialities of transabdominal, transrectal ultrasonography and X-ray computed tomography and to assess their value in diagnosing colonic cancer, including its "minor" forms. The paper describes the ultrasound and computed tomographic semiotics of colonic cancer and determines a place of the above techniques in the algorithm of radiation and instrumental studies. Inclusion of these techniques into the diagnostic algorithm may solve a range of differentially diagnostic problems and allows a preliminary analysis to be made in a tumor lesion according to the International TNM classification. Ultrasonography and X-ray computed tomography should be included into a range of basic methods for diagnosis of colonic cancer.

[Potentialities of ultrasound study in diagnosis of endophytic carcinoma of stomach]

The data of studies of 45 patients with gastric cancer are used to consider the potentialities of ultrasonography (USG) in the diagnosis of its endophytic forms. Its use in the diagnosis of "small" gastric carcinomas is evaluated. The USG semiotics of endophytic tumors of the stomach, including its "small" and early forms, is presented. The place of USG in the diagnostic algorithmic of gastric cancer is specified. In the authors' opinion, gastric USG along with traditional X-ray and endoscopic studies should take an appropriate place as it is beneficial in solving a great deal of differential diagnostic problems associated with the intramural spread of tumors.

[Participation of forensic medics in anthropological examinations of the Orthodox church burials]

Examinations of the rudiments of the Russian Orthodox Saints are reviewed. The burial of holy people in Russia is described. The results of examinations of rudiments of the Saints, Reverend Iosaph of Belgorod, Cornilai Padansky, and Arsenii Konevsky, are presented. A detailed algorithm of expert steps is suggested.

[Electron-microscopic and immunohistochemical study of the reorganization of the microtubule system in granular cells of frog urinary bladder after water transport induction]

Structural changes in organization of the microtubule system in granular cells of frog urinary bladder after water transport induction by vasopressin were studied by methods of electron microscopy and immunocytochemistry. It is shown that in steady-state conditions microtubules form a wide network equally distributed in the whole cytoplasm of granular cells. After vasopressin action, the amount of microtubules increases in the apical region of the cytoplasm. A predominant orientation of microtubules, perpendicular to the apical membrane direction, appears. A structural association of microtubules with specific granules and large vacuoles was observed. A supposition is advanced about association of the described microtubule system reorganization with the activation of vectorial intracellular transport occurring after transepithelial water transport induction.

[Structural rearrangements of microfilaments and granular cells of the frog bladder during induction of water transport: fluorescent microscopic, immunocytochemical and electron microscopic studies]

The structural reorganization of actin cytoskeleton of the frog urinary bladder granular cells, in the process of vasopressin-induced water transport, was studied by fluorescent and electron microscopy, and immunocytochemistry. A significant decrease in density of actin microfilament network under the apical membrane was observed after water transport stimulation. Microfilaments were associated with membranes of large vacuoles emerging in granular cells of vasopressin-treated urinary bladders. A supposition is advanced concerning functional heterogeneity of actin filaments in granular cells.

[X-ray computerized tomography in the differential diagnosis of gastric ulceration]

The results of more than 3000 gastric examinations were used to study the potentialities of X-ray computerized tomography in the differential diagnosis of benign and malignant gastric ulcerations. CT evidence for benign and malignant gastric ulcerations is outlined. The place and role of CT in the diagnostic algorithm for gastric ulcerations are defined. In the authors' opinion, CT is a supplementary study and should be used purposefully after preliminary X-ray, endoscopic, and morphological examinations in difficult clinical situations associated with the differential diagnosis of gastric ulcerations.

[X-ray endoscopic semiotics and diagnostic algorithm of radiation studies of preneoplastic gastric mucosa changes]

The X-ray endoscopic semiotics of precancerous gastric mucosal changes (epithelial dysplasia, intestinal epithelial rearrangement) was examined by the results of 1574 gastric examination. A diagnostic algorithm was developed for radiation studies in the diagnosis of the above pathology.

[The complex forensic medical study of the bony remains from a burial long ago]

A complex of methods of forensic medical expert evaluation of bone rudiments, including identification osteological, spectral, histological, and biological studies, files of historical archives, archaeological and soil science data, helped tentatively determine the time of burial and assess the individual features of subjects buried at the territory of an ancient orthodox monastery.

[Comprehensive clinical and roentgeno-endoscopic examination in the diagnosis of tumors of the large intestine]

A total of 247 patients with diseases of the abdominal organs were examined. 32 patients with rectal tumors were singled out. The diagnosis of "minor" colorectal cancer was particularly difficult. The authors believe that approaches to improvement of early diagnosis of colorectal cancer imply definition of roentgeno-endoscopic signs of rectal wall involvement which will help purposefully and timely detect precancer changes in rectal mucosa (dysplasia) as a marker of high risk of cancer.