А rare case of primary malignant melanoma of the female urethra.

Primary malignant melanoma of the female urethra is an extremely rare disease. Its frequency is only 0.2% of all malignant melanomas. This type of carcinoma is associated with a poor prognosis and short survival due to the early occurrence of metastases and delayed diagnosis. We present a patient with primary malignant melanoma invading the distal urethra, part of the labia minora, and sections of the anterior vaginal wall, where 15 months of overall survival were achieved against the background of the complex treatment.

Primary signet-ring cell adenocarcinoma of the bladder-A case report and review of literature.

Cases of adenocarcinoma of the bladder are extremely low - 2%, respectively. Primary signet-ring cell carcinoma (SRCC) of the bladder accounts for 0.12-0.6% among the different histological subtypes of bladder carcinomas. We present a rare case of SRСС with clinical manifestations of hematuria (two times) treated with transurethral resection of the bladder (TURB). Primary ring cell carcinoma of the bladder is an extremely rare and aggressive tumor. In this case, presented by us, probably due to early diagnosis and radical resection, the prognosis is encouraging.

Attractive curves: the role of deformations in adhesion and friction on graphene.

Friction force microscopy measurements reveal a dramatic difference of a factor 3 between the friction forces experienced on single-monolayer graphene on top of oxidized and unoxidized copper substrates. We associate this difference with the strong and weak adhesion that the graphene experiences on these two substrates, respectively, but argue that it is too large to be ascribed either to a difference in contact area or to a difference in contact commensurability or even to a combination of these two effects. We use density functional theory to show a significant increase in the chemical reactivity of graphene when it is curved.

[Heterogeneity of chronic esophagitis in childhood].

Chronic esophagitis in children etiologically are heterogeneous. Was observed 83 patients aged from 3 to 17 years with histologically defined chronic esophagitis, 58 of them suffered from food and respiratory allergies. All children underwented endoscopy, morphological and immunohistochemical study of the esophagus biopsies with the definition IgE, IgA herpes simplex virus (HSV), cytomegalovirus (CMV) and Epstein - Barr virus (EBV) in the mucous membrane. The presence of chronic infection was established in 77 out of 83 (92.8%) children. All the patients underwented daily pH meters. GERD was diagnosed in 33 children. GERD was characterized by typical symptoms, combined with gastroduodenal pathology, usually Hp-associated, and increased gastric secretion. Morphologically at 15% of the patients with gastric metaplasia was found moderate inflammation. During examination of patients with allergic esophagitis was neither clinical nor explicit endoscopic manifestations, eosinophilic infiltration was observed in some patients, but inflammatory activity was lower than at GERD and infections. Esophagitis in chronic viral infections was characterized by a higher frequency of erosive changes, higher activity of inflammation. The combination of the three etiological factors were associated with more severe lesions of the esophagus.

Unexpected long-term survival in an adult patient with metastatic prostate cancer.

According to statistics, the 5-year overall survival in metastatic prostate cancer is about 21 months. We present a case of a patient with castration-resistant prostate cancer with proven bone lesions 2 years after the onset of the disease and the current survival of over 9 years.

A rare case of double J stent migration in the kidney.

Double-J stents are among the basic and commonly used tools in urology. There are a lot of complications that can occur during DJ placement. We are presenting 62 years old woman, who was admitted in Urology Department with symptoms of left lumbar pain, irradiating towards inguinal area and hematuria. The computed tomography (CT) scan of abdomen and pelvis defined a propagated DJ stent in the left kidney. Lumenis Holmium laser VersaPulse 100 W was used for resection of the double J stent and after that it was removed from the kidney in pieces.

Renal inflammatory myofibroblastic tumor: A case report.

Inflammatory myofibroblastic tumor (IMT) is an extremely rare disease composed of myofibroblast cells and inflammatory infiltrates. There are different sites of the urogenital system affected by IMT-bladder, prostate and kidney. We report a case of a 59-year-old male patient presented with abdominal pain, gross hematuria and a renal mass treated with partial nephrectomy. The final diagnosis was renal inflammatory myofibroblastic tumor. Despite recent improvements in imaging technology, preoperative diagnosis of IMT remains a dilemma. It is therefore mandatory to carry out clinical interpretation, careful histologic examination, and immunohistochemical studies which will generally determine the appropriate diagnosis and patient management.

[Association of the morphological features of gastric parietal cells with the concentration of H+/K+/ATPase autoantibodies in chronic gastrititis].

Chronic gastritis was morphologically verified in 119 patients. The count of parietal cells per 100 epitheliocytes of fundic glands was estimated. The sizes of parietal cells were measured by the morphometric computer program Videotest. For the diagnosis of autoimmune chronic gastritis (ACG), the level of antibodies to H+K+ATPase of gastric parietal cells in the patients' serum was determined by enzyme immunoassay. Childhood ACG has been found to be characterized by hyperplasia and structural changes of parietal cells with their preserved total count. The specific features of adult ACG include a significant reduction in the number of parietal cells, their sizes depending on the level of antiparietal autoantibodies, and marked ultrastructural changes as impairments in the differentiation and destruction of cytoplasm, organelles, and cell membrane.

Age dependent changes of arterial wall viscoelasticity.

Viscoelastic characteristics (VEC) of old rat aorta (Wistar, 10 months) were obtained by sinusoidal excitation of intraluminal pressure (p) in cylindrical arterial preparations. The pressure excitation frequency (f(exc)) was swept in the range 3-30 Hz up and down at several mean-pressure levels while response volume oscillations were recorded and resonance curves were plotted. Natural frequency (f(0)), dynamic modulus of elasticity (E') and coefficient of viscosity (beta) were estimated from resonance curves and the dependences of VEC on p were drawn. The results showed that f(0) decreased linearly with p whereas our previous data for young rat aorta (Wistar, 4 months) showed independence of f(0) on p. E' increased nonlinearly with p with the values being higher in comparison to young rat aorta. This means stiffening of rat aorta with age in accordance with the known literature data. beta-values increased linearly with p being higher in comparison to young rat aorta, demonstrative of raised intrinsic friction in the wall. VEC values were higher at decreasing f(exc) suggesting that the direction of excitation sweeping also determines the arterial wall biomechanical behaviour. It could be concluded that blood vessels VEC worsen with age, which endangers the arterial wall integrity, especially at higher intraluminal pressure.

Grafting of polylysine with polyethylenoxide prevents demixing of O-pyromellitylgramicidin in lipid membranes.

Both natural and synthetic polycations can induce demixing of negatively charged components in artificial and possibly in natural membranes. This process can result in formation of clusters (binding of several components to a polycation chain) and/or domains (aggregation of clusters and formation of a separate phase enriched in some particular component). In order to distinguish between these two phenomena, a model lipid membrane system containing ion channels, formed by a negatively charged peptide, O-pyromellitylgramicidin, and polycations of different structures was used. Microelectrophoresis of liposomes, changes in boundary potential of planar bilayers, the shape of compression curves and potentials of lipid and lipid/peptide monolayers were used to monitor the electrostatic factors in polymer adsorption to the membrane and peptide-polymer interactions. The synthesized PEO-grafted polylysine, PLL-PEO20000, did not induce peptide demixing monitored by stabilization of the gramicidin channels, in contrast to parent polylysine (PLL). Both polymers were shown to bind effectively to negatively charged liposomes and lipid monolayers, suggesting that the ineffectiveness of PLL-PEO20000 was not due to reduction of its binding. It was hypothesized that PLL-PEO20000 could not induce domain formation due to steric hindrance of long PEO chains preventing lateral fusion of clusters. Another copolymer, PLL-PEO4000, having four PEO chains of 4000 Da, exhibited intermediate effect between PLL and PLL-PEO20000, which shows the importance of the copolymer architecture for the effect on the lateral distribution of OPg channels. The model system can be relevant to regulation of lateral organization of ion channels and other components in natural membrane systems.

Influence of membrane phospholipid composition and structural organization on spontaneous lipid transfer between membranes.

Investigations were carried out on the influence of phospholipid composition of model membranes on the processes of spontaneous lipid transfer between membranes. Acceptor vesicles were prepared from phospholipids extracted from plasma membranes of control and ras-transformed fibroblasts. Acceptor model membranes with manipulated levels of phosphatidylethanolamine (PE), sphingomyelin and phosphatidic acid were also used in the studies. Donor vesicles were prepared of phosphatidylcholine (PC) and contained two fluorescent lipid analogues, NBD-PC and N-Rh-PE, at a self-quenching concentration. Lipid transfer rate was assessed by measuring the increase of fluorescence in acceptor membranes due to transfer of fluorescent lipid analogues from quenched donor to unquenched acceptor vesicles. The results showed that spontaneous NBD-PC transfer increased upon fluidization of acceptor vesicles. In addition, elevation of PE concentration in model membranes was also accompanied by an increase of lipid transfer to all series of acceptor vesicles. The results are discussed with respect to the role of lipid composition and structural order of cellular plasma membranes in the processes of spontaneous lipid exchange between membrane bilayers.

Thermofusion of cells.

This communication provides evidence that the thermo-osmotically induced membrane defects and fluxes occurring in plant protoplasts may initiate internalization and fusion of adjacent cells. This phenomenon is called thermofusion of cells.

Radioiodination of naturally occurring phospholipids.

A simple and rapid nonenzymatic method for radioiodination of phospholipids is described. It involves oxidation of Na125I with TlCl3 (or chloramine-T) in an aqueous medium, with subsequent exposure of the phospholipids, dissolved in chloroform/methanol, to the action of the oxidizing mixture. Purification of the radiolabelled phospholipids was effected by washing with sodium thiosulphate followed by thin-layer chromatography on silica gel. Specific radioactivity of 125I-labelled phosphatidylcholine was estimated to be about 10 muCi/mg phospholipid. The method is designed for radioiodination of various naturally occurring phospholipids.

Heat shock and osmotically dependent steps by DNA uptake after Escherichia coli electroporation.

Currently, the major problem in the genetic transformation is to understand how such a large molecule as the plasmid DNA passes through the cell membrane. To solve this problem we used a simplified experimental model with Escherichia coli and the plasmid pBR322: the DNA-bacteria mixture was electroporated in a sucrose solution at 0 degree C and at fixed electrical parameters; the samples were then directly plated into agar. It was found that the electrically-induced bacterial transformation after pulsing is dependent on two factors: heat shock (delta T) and osmotic stress. Our results indicate that two mechanisms contribute to these effects: (i) thermodiffusion of the DNA across the membrane and (ii) osmotic flows of the medium, containing the DNA, into the interior of the cell.

Membrane-related thermo-osmotic effect as measured by medium conductivity in isotonic cell suspensions.

Changes in temperature result in changes in cell-membrane permeability for water and solutes. At isotonic conditions this thermo-osmotic effect is relatively small and remains indistinguishable by the ordinary impedance methods. The thermo-osmotic effect can be investigated in cell suspensions in the beta-dispersion region (high-frequency electric field with an intensity of 100-300 V/cm, peak-to-peak). The current through the cell suspension of Nicotiana tabacum protoplasts (or human erythrocytes) is a nonlinear function of temperature jump and/or cooling rate. In experiments carried out in a microchamber with thermostatted electrodes at supra-zero temperatures quantitative data were obtained for the thermo-osmotic phenomenon in cell suspension as well as for individual cells.

Oxidative damage of the membrane lipids after electroporation.

Electric field pulses used for cell manipulation can cause irreversible cell damage. The mechanisms of the processes leading to such cell damage are very complicated. Our work demonstrated that exponential electric pulses with intensity of 2-7.5 kV/cm and duration of 5.2 ms were able to initiate peroxidation of fatty acid emulsions, liposomal membranes, red blood and Ehrlich ascite tumor cells. Electric pulses-induced peroxidation of erythrocyte membranes was followed by hemolysis. The electric treatment caused damage of E. coli membrane lipids which was accompanied by decreased cell survival. All these effects depended on field intensity. A relatively good correlation between pulse-induced peroxidation of erythrocyte membranes and hemolysis was observed. These results suggest that free radical mediated processes as lipid peroxidation and/or lipid degradation or fragmentation may be possible causes for electric pulses-induced irreversible cell damage.

[ Multigeneration carcinogenesis in the evaluation and prognosis of delayed radiation effects]. / Znachenie multigeneratsionnogo kantserogeneza v otsenke i prognoze otdalënnykh radiatsionnykh éffectov.

Radiation multigeneration carcinogenesis' mechanisms are associated with inheritance of non-specific genome lesions. Evidence indicates that the effect is significantly enhanced by some chemical carcinogens action on the offspring of irradiated parents. Hereditary character of the phenomenon is a prerequisite to accumulation of these genetic determinants in the population. The risk of radiation multigeneration carcinogenesis for man could be as much as 0.4 x 10(-2) Sv-1 over one generation.

[Pseudomutagenesis. The persistent increase in the level of cellular variability induced by radiation and some other agents]. / K probleme psevdomutageneza. Persistiruiushchee povyshenie urovnia izmenchivosti kletok, indutsiruemoe radiatsiei i nekotorymi drugimi agentami.

Electron microscopic investigation of capillary endothelium cells in myocardium of irradiated rats revealed an unusual effect of persistent increase of probability of cell damage, similar in many relations to that described earlier for various unicellular species. New effect, unlike those traditionally studied, is characterised by non-stochastic nature, large number of the involved cells, reveals itself even after faint influences, and can be induced as well by agents other than radiation. The question is put on the probable commonness between these changes and the pseudomutagenesis which has the similar phenomenology.

[Increase of probability of cell loss in the endothelium of blood vessel capillaries in progeny of rats after a low-dose irradiation of one of the parents (electron microscopy study)]. / Povyshenie veroiatnosti gibeli kletok v éndotelii krovenosnykh kapilliarov u potomkov krys posle oblucheniia odnogo iz roditelei v malykh dozakh (élektronno-mikroskopicheskoe issledovanie).

The total gamma-irradiation of Wistar rats at a dose of 0.25 Gy as well as at higher doses (0.5, 2 and 4.5 Gy) produces in the capillary endothelial cells of myocardium and lung a pronounced, dose-independent increase of the yield of necrotized cells. Similar changes were revealed in the animals, of which one of the parents (a male one day, a female seven days prior to copulation) was irradiated at doses of 0.25 and 0.5 Gy. This effect was observed in all studied descendants. The massive induction of the changes already by low radiation actions and their dose-independence allow considering the revealed effects as a manifestation of peculiar cellular reactions that presumably have epigenetic nature.

[The radiation hygiene problems of multigenerational carcinogenesis]. / Radiatsionno-gigienicheskie problemy mul'tigeneratsionnogo kantserogeneza.

This review deals with a phenomenon of multigeneration carcinogenesis; the carcinogenic risk for offsprings of irradiated persons can be estimated as 4.10(-3) Sv-1. Though some epidemiological findings in this area are contradictory, multigeneration carcinogenesis may present a part of a population risk (genetic load). There is a need for recording the phenomenon in the normal ranges of radiation safety, i.e. to limit the planned irradiation of males aged 30-40 years, as well as females of the same age.