Course Of Adhesion Research Articles

Determination of the proliferative activity of the endometrium during the period of the implantation window in veteran women of reproductive age with a history of contusion

Today, more than 50.000 women serve in the Armed Forces of Ukraine. The number of people with post-traumatic stress disorder is 27.7 % among military personnel who took part in active combat operations. Post-traumatic syndrome is a frequent predictor of various states of proliferative activity of the endometrium in veteran women of reproductive age with changes in the hormonal background, morphofunctional changes of the endometrium, which in turn negatively affects the reproductive health of women. The purpose of the work: to determine the proliferative activity of the endometrium in patients of reproductive age who took part in hostilities and suffered a concussion. The selection criteria of the women included in the study were: the presence of contusion in the anamnesis, normospermia in the husband, the absence of pregnancy within a year after putting the main disease into remission, and unfulfilled reproductive plans. The age of the examined women ranged from 20 to 40 years. 457 women who took part in combat operations and suffered concussions were examined. The criterion for inclusion in the main group (O) was post-concussive syndrome as a consequence of a concussion sustained during hostilities. The number of examinees was 211 women. The criterion for inclusion in the comparison group (P) (n=246 women) was a concussion during combat operations, but the absence of post-concussion syndrome. The control group (K) included 30 civilian women without episodes of any trauma in the anamnesis. Clinical, instrumental and morphological research methods were used during the research. The most significant differences in the number of immunopositive endometrial cells in the state of proliferation and apoptosis were noted between groups P and O in chronic endometritis and simple atypical hyperplasia of the endometrium. Thus, in the structure of the endometrium of women with reproductive plans who participated in hostilities with episode of contusion in anamnesis, an increase in the proliferation processes in the glands and stroma of the endometrium against the background of intensification of the processes of apoptosis in the stroma and a decrease in the processes of apoptosis in the glands, which may interfere with the normal course of adhesion, was characteristic blastocysts and trophoblast invasions during implantation.

Strain specific motility patterns and surface adhesion of virulent and probiotic Escherichia coli

Bacterial motility provides the ability for bacterial dissemination and surface exploration, apart from a choice between surface colonisation and further motion. In this study, we characterised the movement trajectories of pathogenic and probiotic Escherichia coli strains (ATCC43890 and M17, respectively) at the landing stage (i.e., leaving the bulk and approaching the surface) and its correlation with adhesion patterns and efficiency. A poorly motile strain JM109 was used as a control. Using specially designed and manufactured microfluidic chambers, we found that the motion behaviour near surfaces drastically varied between the strains, correlating with adhesion patterns. We consider two bacterial strategies for effective surface colonisation: horizontal and vertical, based on the obtained results. The horizontal strategy demonstrated by the M17 strain is characterised by collective directed movements within the horizontal layer during a relatively long period and non-uniform adhesion patterns, suggesting co-dependence of bacteria in the course of adhesion. The vertical strategy demonstrated by the pathogenic ATCC43890 strain implies the individual movement of bacteria mainly in the vertical direction, a faster transition from bulk to near-surface swimming, and independent bacterial behaviour during adhesion, providing a uniform distribution over the surface.

Pneumococcal capsular phase shift is associated with invasion into cell-to-cell junctions and is inhibited by macrolides

Streptococcus pneumoniae frequently colonizes the human nasopharynx beginning in the early childhood. Pneumococci exhibit a spontaneous and reversible phase shift between opaque and transparent allowing them to adapt to different environments. This is the first report of the dynamics of pneumococcal phase shift during the course of adhesion and subsequent invasion into epithelial cell monolayers by bacteria-cell co-culture assay with a time-lapse microscopy. The invasion of an inoculum between the human epithelial cells was dependent on the transparent phenotype, but successful replication of the cells within the cell layer was strongly associated with its transformation into an opaque-like variant. We also observed that sub-MIC levels of clarithromycin inhibited the spontaneous pneumococcal phase shift. Our results show that the pneumococcus can modulate its fitness in part because it can switch phenotype in response to the environment during not only inflammation but also during the establishment of colonization. Our current findings provide a more in depth understanding not only of how the pneumococcal phase shift acts to protect pneumococci from commensal flora and the immune status of the host, but also illustrate a novel strategy for antimicrobial treatments to interfere with pneumococcal colonization.

Characterization of key mechanisms in transmigration and invasion of mesenchymal stem cells

For successful systemic stem cell therapy, mesenchymal stem cells (MSCs) must transmigrate across the endothelium and invade their target tissue. To date, most of the underlying mechanisms of transmigration and invasion remain to be elucidated. Improving our knowledge on these core processes might elevate the efficiency of stem cell therapy. Our aim was therefore to characterize key mechanisms involved in transmigration and invasion of MSCs. Co-cultivation experiments infer that MSCs integrate into the endothelial monolayer. However, the time course of adhesion, integration and transmigration depends on the endothelial phenotype and is most effective in venous vessels of the myocardium. Thus, a variable capacity for transmigration exists within the vasculature. Additionally, three-dimensional systems reveal that MSCs penetrate the endothelium and invade the surrounding tissue via plasmic podia. Furthermore, transmigration not only requires the interaction of vascular cell adhesion molecule-1 (VCAM-1) and very late antigen-4 (VLA-4) as verified by blocking experiments, but also triggers the clustering of β1 integrins. In addition, in situ zymographies infer the activation of gelatinases at sites of MSC invasion into myocardial tissue. As evidenced by ELISA, MSCs secrete matrix metalloproteinase (MMP)-2 but not MMP-9. Finally, media containing additional cytokines accelerate the transmigration. Concluding, key players involved in transmigration and invasion of MSCs are the endothelial phenotype, VCAM-1/VLA-4, β1 integrins, MMP-2 secretion and cytokines.

Peculiarities of adhesion of epiphytic bacteria on leaves of the seagrass Zostera marina and on abiotic surfaces

A comparative study of the adhesion of epiphytic bacteria and marine free-living, saprophytic, and pathogenic bacteria on seagrass leaves and abiotic surfaces was performed to prove the occurrence of true epiphytes of Zostera marina and to elucidate the bacterium-plant symbiotrophic relationships. It was shown that in the course of adhesion to the seagrass leaves of two taxonomically different bacteria, Cytophaga sp. KMM 3552 and Pseudoalteromonas citrea KMM 461, isolated from the seagrass surface, the number of viable cells increased 3-7-fold after 60 h of incubation, reaching 1.0-2.0 x 10(5) cells/cm2; however, in the case of adhesion of these bacteria to abiotic surfaces, such as glass or metal, virtually no viable cells were observed after 60 h of incubation. Such selectivity of cell adhesion was not observed in the case of three other bacterial species studied, viz., Vibrio alginolyticus KMM 3551, Bacillus subtilis KMM 430, and Pseudomonas aeruginosa KMM 433. The amount of viable cells of V. alginolyticus KMM 3551 adsorbed on glass and metal surfaces increased twofold after 40 h of incubation. The cells of saprophytic B. subtilis KMM 430 and pathogenic P. aeruginosa KMM 433 adsorbed on three studied substrata remained viable for 36 h and died by the 60th hour of incubation.

Mass Spectrometry-Based Proteomics and its Application to Studies of Porphyromonas gingivalis Invasion and Pathogenicity

Porphyromonas gingivalis is a Gram-negative anaerobe that populates the subgingival crevice of the mouth. It is known to undergo a transition from its commensal status in healthy individuals to a highly invasive intracellular pathogen in human patients suffering from periodontal disease, where it is often the dominant species of pathogenic bacteria. The application of mass spectrometry-based proteomics to the study of P. gingivalis interactions with model host cell systems, invasion and pathogenicity is reviewed. These studies have evolved from qualitative identifications of small numbers of secreted proteins, using traditional gel-based methods, to quantitative whole cell proteomic studies using multiple dimension capillary HPLC coupled with linear ion trap mass spectrometry. It has become possible to generate a differential readout of protein expression change over the entire P. gingivalis proteome, in a manner analogous to whole genome mRNA arrays. Different strategies have been employed for generating protein level expression ratios from mass spectrometry data, including stable isotope metabolic labeling and most recently, spectral counting methods. A global view of changes in protein modification status remains elusive due to the limitations of existing computational tools for database searching and data mining. Such a view would be desirable for purposes of making global assessments of changes in gene regulation in response to host interactions during the course of adhesion, invasion and internalization. With a complete data matrix consisting of changes in transcription, protein abundance and protein modification during the course of invasion, the search for new protein drug targets would benefit from a more comprehensive understanding of these processes than what could be achieved prior to the advent of systems biology.

The induction of TGF-beta(1) and NF-kappaB parallels a biphasic time course of leukocyte/endothelial cell adhesion following low-dose X-irradiation.

Low-dose radiotherapy (LD-RT) is known to exert an anti-inflammatory effect, but the knowledge of the underlying molecular mechanisms is still scarce. The authors have recently reported that transforming growth factor beta 1 (TGF-beta(1)) essentially contributes to a reduced endothelial adhesion of mononuclear cells (PBMC) following LD-RT. Furthermore, TGF-beta(1) secretion was associated with the induction of the transcription factor nuclear factor kappa B (NF-kappaB). However, the time course of adhesion, TGF-beta(1) expression, and NF-kappaB activity following LD-RT has not been thoroughly investigated yet. The human EA.hy.926 endothelial cell line (EA.hy.926 EC) was grown to 95% confluence. Immediately after stimulation with the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), EA.hy.926 EC were irradiated with single doses ranging from 0.3 up to 3 Gy. Adhesion assays were performed 4, 12, and 24 h after irradiation. Nuclear extracts and culture supernatants were harvested after 4, 8, 12, 20, 24, 30, and 40 h. NF-kappaB DNA-binding activity was analyzed by electrophoretic mobility shift assays (EMSA) and TGF-beta(1) secretion by enzyme-linked immunosorbent assay (ELISA). The functional impact of TGF-beta(1) on the course of leukocyte/EC adhesion was analyzed by neutralizing TGF-beta(1) in parallel with stimulation/irradiation of the EA.hy.926 EC. 4 and 24 h after irradiation of EA.hy.926 EC in the dose range between 0.3 and 0.7 Gy, a reduced adhesion of PBMC compared to nontreated controls could be observed. However, 12 h after irradiation a relative maximum of adhesion (up to 30% increase) was seen at a dose of 0.3 Gy. TGF-beta(1) secretion and NF-kappaB DNA-binding activity displayed a similar biphasic kinetics of induction with a relative minimum 12 h after irradiation. Neutralization of TGF-beta(1) activity restored adhesion at 4 and 24 h after LD-RT of EA.hy.926 EC, but it did not influence leukocyte adhesion 12 h after irradiation. LD-RT of stimulated human EA.hy.926 EC is followed by a biphasic time course of NF-kappaB activity and an increased secretion of TGF-beta(1). The kinetics shows peak levels at 4-8 h and 24-30 h after LD-RT and results in a biphasic leukocyte/EC adhesion profile.

Adhesion of Azospirillum brasilense: role of proteins at the cell-support interface

The adhesion of the soil bacterium Azospirillum brasilense to polystyrene has been investigated using a parallel-plate chamber in conditions allowing cell transport to the support by sedimentation and rinsing under controlled hydrodynamic conditions. The adhesion pattern, which was heterogeneous, and the density of adhering cells were determined by cell aggregation at the support surface and detachment of aggregates upon rinsing. Determination of the support surface composition by X-ray photoelectron spectroscopy after detachment of adhering cells and analysis of the supernatant of cell suspensions revealed that, during the course of adhesion, extracellular proteins are released progressively into the aqueous phase and adsorb at the support surface. Support preconditioning by contact with a cell suspension promoted adhesion after a short contact time (2 h) due to protein adsorption at the support surface. Cell ageing prior to the adhesion test also enhanced adhesion after 2 h due to protein accumulation at the cell surface. Moreover, when supports were preconditioned and when cells were aged prior to the test, adhesion was still dependent on cell-support contact time, which pointed to the influence of in situ secretion of proteins by the adhering cells. It was therefore concluded that the role played by proteins at the cell-support interface is twofold. In the first stage, proteins accumulate at the cell surface, are liberated into the solution and adsorb at the support surface; the increase of the protein concentration at the interface promotes initial adhesion. In the next stage, in situ secretion of proteins during the prolonged contact between the cells and the support strengthens adhesion.

ＴｉＣ基サーメットとＷＣ‐Ｃｏ合金との接着に関する研究

The titanium carbide (TiC) based cermet has often been known as a material showing a higher resistance to wear than that of WC-Co cemented carbide in the use of tools for working steels. However, the brazing characteristic of cermet to tool steels is inferior to cemented carbide. Then, the studies on adhesion between the cermet and WC-Co alloy were made to get fundamental knowledges in making combination tools. The cermet and WC-Co alloy were pre-adhered at 1300°C, and finally adhered at 1360-1400°C . It was found that liquid binder of nickel appearing in cermet generally flowed out into WC-Co alloy during the course of adhesion, resulting in the hardness increase and the volume (dimension) decrease in cermet, and in the reverse phenomena in WC-Co alloy side. The flow out of liquid nickel of cermet occurred during rising temperature to adhesion temperature and lowering temperature from the above temperature. The amount of flow out of liquid nickel depended on the adhesion temperature, grain size, carbon content of specimens and cooling rate from adhesion temperature. The mechanism of flow out of liquid nickel was in detail discussed.

Determination and kinetics of platelet adhesion onto material surfaces

An apparatus for the quantitative measurement of platelet adhesion onto a material surface has been constructed by combining a rheoscope with video-image processors. Time courses of the adhesion were obtained by separating the video images of adhered spots from those of flowing platelets in microscopic video frames, and by encoding the area and number of these spots. p]The time course of human platelet adhesion was simulated numerically, on the basis of a simplified kinetic model. In the experiment with a polymethylmethacrylate plate, the rate constant of the platelet adhesion onto the free surface is far smaller than that onto the adhered platelets.