Role Of Individual Cells Research Articles

Expression of CD44 and CD133 in tumor сells of metastatic and non-metastatic gastric cancer.

e15531 Background: High incidence and mortality rates of gastric cancer cause a constant search for the most informative and effective methods of diagnosis and treatment assessment. In this regard, studying the expression of markers with the stem phenotype in primary tumor tissues in patients with gastric cancer with and without metastases is of undoubted interest. Methods: The study included 20 gastric cancer patients aged 30-80 years: group 1 – gastric cancer T3-4аN0-3M0 (G2) without metastasis (58.9±9.7 years); group 2 – gastric cancer T3-4аN0-3M1 (G2) with peritoneal metastasis (53.4±11.9 years). Immunohistochemical study was performed on paraffin-embedded tumor tissue sections using mouse monoclonal antibodies to CD44 (156-3С11 Thermo Scientific) at a 1:2500 dilution and rabbit polyclonal antibodies to CD133 (Cloud-Clone Corp.) at a 1:700 dilution; the Thermo Scientific autostainer was used for staining. Membrane staining and staining intensity were assessed: 0, 1+ weak, 2+ moderate, 3+ strong staining. Positive expression was defined as ≥10% cut-off for CD44 and ˃5% for CD133. Results: Positive expression of CD44+ was detected in 67% (13) in group 2 vs. 20% (4) in group 1. In the metastatic group, the number of cells that stained positive for CD44 expression ranged from 9 to 15%, on average 10.0±3.08%, without metastases – from single cells to 13%, on average 6.0±2.3%. A chi-square test showed statistically significant association in the groups (8.256 at p = 0.004). Positive CD133+ expression in tumor tissues was registered in 100% (20) in group 2 and 80% (16) in group 1. The range of positively stained cells in group 2 was from 10 to 40%, on average 21.3±11.6%, in group 1 - from single cells to 14%, on average 10.0±2.4%. A chi-square test showed statistically significant association in the groups (4.444 at p = 0.036). Conclusions: Immunohistochemical study of the selected tumor cell markers in gastric cancer revealed some characteristics of their expression depending on the presence of metastases. The results can be the basis for further research for the most complete characterization of a heterogeneous tumor population in gastric cancer and the role of individual cells in the tumor growth, progression and metastasis.

Fundamentalni doslidzhennia v oftalmolohii – suchasna perspektyva novykh pidkhodiv do pervynnoi ta vtorynnoi profilaktyky sudynnykh zakhvoriuvan orhana zoru

This paper is presenting the literary materials about the necessity and importance of basic research in the field of medicine, particularly ophthalmology. These data revealed the analysis of well-known studies conducted by our famous scientists from different branches of medicine to explore different aspects of the functioning of the retina, to investigate the mechanisms of formation of the visual image, to define the role of individual cells in the function of color vision with different methods, to reveal the effects of ionizing radiation on the lens after Chernobyl disaster. This article contains the information about the results of learning the peculiarities of physiological and pathological processes in retina cells on the intracellular and membrane levels using the unique experimental techniques. The history aspects of some basic research in medicine and ophthalmology are revealed too. On these data the authors demonstrate the evidence of high information content and the importance of interdisciplinary research in the resolving of complex medical problems for the future of ophthalmology with involving the more informative methods of different subjects of medicine.

Long-Term Stability of Visual Pattern Selective Responses of Monkey Temporal Lobe Neurons

Many neurons in primate inferotemporal (IT) cortex respond selectively to complex, often meaningful, stimuli such as faces and objects. An important unanswered question is whether such response selectivity, which is thought to arise from experience-dependent plasticity, is maintained from day to day, or whether the roles of individual cells are continually reassigned based on the diet of natural vision. We addressed this question using microwire electrodes that were chronically implanted in the temporal lobe of two monkeys, often allowing us to monitor activity of individual neurons across days. We found that neurons maintained their selectivity in both response magnitude and patterns of spike timing across a large set of visual images throughout periods of stable signal isolation from the same cell that sometimes exceeded two weeks. These results indicate that stimulus-selectivity of responses in IT is stable across days and weeks of visual experience.

Context-dependent perceptual modulation of single neurons in primate visual cortex

Some neurons in the visual cortex alter their spiking rate according to the perceptual interpretation of an observed stimulus, rather than its physical structure alone. Experiments in monkeys have suggested that, although the proportion of neurons showing this effect differs greatly between cortical areas, this proportion remains similar across different stimuli. These findings have raised the intriguing questions of whether the same neurons always participate in the disambiguation of sensory patterns and whether such neurons might represent a special class of cortical cells that relay perceptual signals to higher cortical areas. Here we explore this question by measuring activity in the middle temporal cortex of monkeys and asking to what degree the percept-related responses of individual neurons depend upon the specific sensory input. In contrast to our expectations, we found that even small differences in the stimuli led to significant changes in the signaling of the perceptual state by single neurons. We conclude that nearly all feature-responsive neurons in this area, rather than a select subset, can contribute to the resolution of sensory conflict, and that the role of individual cells in signaling the perceptual outcome is tightly linked to the fine details of the stimuli involved.

MODELING A SMALL NEURONAL NETWORK: THE LOBSTER CARDIAC GANGLION

The lobster cardiac ganglion is a nine cell network that stimulates the lobster heart. The individual neurons are modeled by a simple biophysical bursting model. The neurons are then connected to form the network. Theoretical experiments examine the role of individual cells and network connectivity, in bringing about the network behavior.