scholarly journals Two types of high inductive electromagnetic stimulation and their different effects on endothelial cells

2019 ◽  
pp. 611-622
Author(s):  
J. Průcha ◽  
J. Skopalik ◽  
V. Socha ◽  
L. Hanáková ◽  
L. Knopfová ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cultured Cells ◽  
Low Frequency ◽  
Rectangular Pulse ◽  
Pulse Mode ◽  
Recovery Processes ◽  
Electromagnetic Stimulation ◽  
Coculture Model ◽  
Basic Parameters ◽  
Tissue Recovery

Effects of low-frequency electromagnetic fields (LF EMF) on the activation of different tissue recovery processes have not yet been fully understood. The detailed quantification of LF EMF effects on the angiogenesis were analysed in our experiments by using cultured human and mouse endothelial cells. Two types of fields were used in the tests as follows: the LF EMF with rectangular pulses, 340-microsecond mode at a frequency of 72 Hz and peak intensity 4 mT, and the LF EMF with sinusoidal alternating waveform 5 000 Hz, amplitude-modulated by means of a special interference spectrum mode set to a frequency linear sweep from 1 to 100 Hz for 6 s and from 100 Hz to 1 Hz return also for 6 s, swing period of 12 second. Basic parameters of cultured cells measured after the LF EMF stimulus were viability and proliferation acceleration. Both types of endothelial cells (mouse and human ones) displayed significant changes in the proliferation after the application of the LF EMF under conditions of a rectangular pulse mode. Based on the results, another test of the stimulation on a more complex endothelial-fibroblast coculture model will be the future step of the investigation.

scholarly journals Influence of Duty Ratio and Current Mode on Robot 316L Stainless Steel Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 508
Author(s):  
Ping Yao ◽  
Hongyan Lin ◽  
Wei Wu ◽  
Heqing Tang
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Low Frequency ◽  
Single Pulse ◽  
Pulse Mode ◽  
Double Pulse ◽  
Duty Ratio ◽  
Utilization Rate ◽  
Specimen Height

Wire and arc additive manufacturing (WAAM) is usually for fabricating components due to its low equipment cost, high material utilization rate and cladding efficiency. However, its applications are limited by the large heat input decided by process parameters. Here, four 50-layer stainless steel parts with double-pulse and single-pulse metal inert gas (MIG) welding modes were deposited, and the effect of different duty ratios and current modes on morphology, microstructure, and performance was analyzed. The results demonstrate that the low frequency of the double-pulse had the effect of stirring the molten pool; therefore, the double-pulse mode parts presented a bigger width and smaller height, finer microstructure and better properties than the single-pulse mode. Furthermore, increasing the duty ratio from 35% to 65% enlarged the heat input, which then decreased the specimen height, increased the width, and decreased the hardness and the tensile strength.

The Ets-related transcription factor PU.1 immortalizes erythroblasts

1993 ◽  
Vol 13 (9) ◽  
pp. 5670-5678
Author(s):  
S Schuetze ◽  
P E Stenberg ◽  
D Kabat
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Cell Lines ◽  
Cultured Cells ◽  
Low Frequency ◽  
In Vivo Studies ◽  
Bone Marrow Cultures ◽  
Clonal Cell Lines ◽  
Related Transcription Factor

In vivo studies of Friend virus erythroleukemia have implied that proviral integrations adjacent to the gene for the Ets-related transcription factor PU.1 may inhibit the commitment of erythroblasts to differentiate and cause their capability for indefinite transplantation (C. Spiro, B. Gliniak, and D. Kabat, J. Virol. 62:4129-4135, 1988; R. Paul, S. Schuetze, S. L. Kozak, C. Kozak, and D. Kabat, J. Virol. 65:464-467, 1991). To test this hypothesis, we ligated PU.1 cDNA into a retroviral vector and studied its effects on cultured cells. Infection of fibroblasts with PU.1-encoding retrovirus resulted in PU.1 synthesis followed by nuclear pyknosis, cell rounding, and degeneration. In contrast, in long-term bone marrow cultures, erythroblasts were efficiently and rapidly immortalized. The resulting cell lines were polyclonal populations that contained PU.1, were morphologically blast-like, required erythropoietin and bone marrow stromal cells for survival and proliferation, and spontaneously differentiated at low frequency to synthesize hemoglobin. After 9 months in culture, erythroblasts became stroma independent, and they then grew as clonal cell lines. We conclude that PU.1 perturbs the pathway(s) that controls potential for indefinite proliferation and that it can be used to generate permanent erythroblast cell lines.

scholarly journals Use of biophysical methods to improve yields and quality of agricultural products

2008 ◽  
Vol 53 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Branko Marinkovic ◽  
Miroslav Grujic ◽  
Dusko Marinkovic ◽  
Jovan Crnobarac ◽  
Jelena Marinkovic ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Biological Systems ◽  
Low Frequency ◽  
Crop Species ◽  
Human Environment ◽  
Electromagnetic Stimulation ◽  
Stimulation Method ◽  
Living Organisms ◽  
Novi Sad ◽  
The University

Until as recently as a century ago, the exposure of biological systems to radiation was limited only to the natural sources. Today, however, a broad range of radiation types and doses have found a wide variety of uses and applications, so much so that it would be difficult to make a list of all the areas of human activity in which radiation is used for one purpose or another. The study of radiation effects on individuals and populations as a whole has become important only with the development of methods and sources of man-made radiation. Given that what is present in this case are physical effects on biological systems (living organisms), all these methods can be placed under the heading of biophysical influences. In the last 50 years, the effects of extremely low-frequency electromagnetic fields (ELF-EMF) have been studied with great diligence. These fields are the ones most commonly found in the human environment and they have been used in our studies in this field. The present paper provides a brief review of the literature data and our findings on the effects of ELF-EMF on various crop species using the RIES (Resonant Impulse Electromagnetic Stimulation) method, developed at the Faculty of Agriculture of the University of Novi Sad.

INTERACTION BETWEEN CULTURED ENDOTHELIAL CELLS AND ABNORMAL ANTITHROMBIN III "TOYAMA"

1987 ◽  
Author(s):  
N Sakuragawa ◽  
S Saitoh ◽  
K Takahashi
Keyword(s):  
Endothelial Cells ◽  
Room Temperature ◽  
Antithrombin Iii ◽  
Cultured Cells ◽  
Binding Activity ◽  
Endothelial Cell Culture ◽  
Antithrombin Activity ◽  
Thrombin Activity ◽  
Cultured Endothelial Cells ◽  
At Iii

Purpose: Abnormal antithrombin III(AT-III)Toyama showed non-affinity to heparin and heparinoid to show loss of immediate antithrombin activity. On the endothelial cells, there are heparinoids including heparan sulfate. We investigated on the interaction between cultured endothelial cells and abnormal AT-III"Toyama" from the viewpoint of antithrombin activity.Materials and methods: (1) Endothelial cell culture:^125I-labelled normal and abnormal AT-III were placed on the washed endothelial cultured cells in 0.2 ml of RPMI-1640 medium for 15 min at 37°C. The medium was suctioned off and the cell layer was washed with Hank's balanced salt solution. The cells were incubated with 1 ml of heparin(3 ug/ml) for 15 min at 4°C. The radioactivity in the supernatant was counted, and represented AT-III which bound to the cells surface. (2) Antithrombin activity: 0.23 ml of thrombin solution^ U/ml) and 0.03 ml of normal or abnormal AT-III plasma were mixed, and incubated on the cultured cell surface for 5 min at room temperature. The residual thrombin activity was assayed by 0.3 ml of the substrate (S-2238) solution(0.8mM)for 5 min. After these procedures,2 ml of 2% citric acid solution was added to stop the reaction, and 0D(405 nm) was recorded.Results: Abnormal AT-III showed reduced binding-activity to cultured cells to one fifth compared with normal AT-III, and the residual thrombin activity in the abnormal was higher compared with that in normal plasma.Conclusion: Abnormal AT-III showed less binding activity to the cultured endothelial cells, and less thrombin neutralizing activity to show thrombogenic tendency.

Molecular adaptation of vascular endothelial cells to oxidative stress

1993 ◽  
Vol 264 (3) ◽  
pp. C715-C722 ◽  
Author(s):  
D. Lu ◽  
N. Maulik ◽  
I. I. Moraru ◽  
D. L. Kreutzer ◽  
D. K. Das
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cultured Cells ◽  
Vascular Endothelial Cells ◽  
Molecular Adaptation ◽  
Vascular Endothelial ◽  
Trypan Blue Exclusion ◽  
Two Dimensional Gel Electrophoresis ◽  
H2o2 Treatment ◽  
Trypan Blue Exclusion Test

Cellular organisms respond at the cellular and molecular level when confronted with sudden changes in environment, and molecular adaptation represents the ability of the cells to acclimate themselves to their new environment. In this study we examined the response of bovine vascular endothelial cells (VEC) to the oxidative stress by exposing the cultured cells to two different concentrations of H2O2, 0.04 or 0.08 mM, for 18-24 h. H2O2-exposed VEC displayed good viability (85-90% for 0.04 mM H2O2; 75-80% for 0.08 mM H2O2) and exhibited normal morphology. H2O2 treatment of the VEC was associated with the expression of a number of new proteins, as demonstrated by two-dimensional gel electrophoresis of total cell lysate. Cells exposed to 0.04 mM H2O2 expressed 25 new proteins, whereas 19 newly expressed proteins were detected when the cells were exposed to 0.08 mM H2O2. Western blot analysis of H2O2-treated VEC using specific antibodies to heat-shock proteins (HSP) identified one of these proteins as a member of the HSP 70 family. In addition, H2O2 induced an increase in antioxidative enzyme activities in the VEC, including superoxide dismutase, catalase, and glutathione peroxidase. Moreover, these changes were a truly adaptive phenomenon because challenging the VEC with brief exposure to toxic levels of H2O2 (1 mM for 30 min) showed increased viability (by Trypan blue exclusion test) and decreased injury (by lactate dehydrogenase supernatant-to-cellular ratio determination) in adapted cells (preexposed to 0.04 or 0.08 mM H2O2) compared with control cells.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Ets-related transcription factor PU.1 immortalizes erythroblasts.

1993 ◽  
Vol 13 (9) ◽  
pp. 5670-5678 ◽  
Author(s):  
S Schuetze ◽  
P E Stenberg ◽  
D Kabat
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Cell Lines ◽  
Cultured Cells ◽  
Low Frequency ◽  
In Vivo Studies ◽  
Bone Marrow Cultures ◽  
Clonal Cell Lines ◽  
Related Transcription Factor

In vivo studies of Friend virus erythroleukemia have implied that proviral integrations adjacent to the gene for the Ets-related transcription factor PU.1 may inhibit the commitment of erythroblasts to differentiate and cause their capability for indefinite transplantation (C. Spiro, B. Gliniak, and D. Kabat, J. Virol. 62:4129-4135, 1988; R. Paul, S. Schuetze, S. L. Kozak, C. Kozak, and D. Kabat, J. Virol. 65:464-467, 1991). To test this hypothesis, we ligated PU.1 cDNA into a retroviral vector and studied its effects on cultured cells. Infection of fibroblasts with PU.1-encoding retrovirus resulted in PU.1 synthesis followed by nuclear pyknosis, cell rounding, and degeneration. In contrast, in long-term bone marrow cultures, erythroblasts were efficiently and rapidly immortalized. The resulting cell lines were polyclonal populations that contained PU.1, were morphologically blast-like, required erythropoietin and bone marrow stromal cells for survival and proliferation, and spontaneously differentiated at low frequency to synthesize hemoglobin. After 9 months in culture, erythroblasts became stroma independent, and they then grew as clonal cell lines. We conclude that PU.1 perturbs the pathway(s) that controls potential for indefinite proliferation and that it can be used to generate permanent erythroblast cell lines.

Demonstration of Antithrombin III in Fresh and Cultured Endothelial Cells from Human Umbilical Cord

1979 ◽  
Author(s):  
Vivian Chan ◽  
T.K. Chan
Keyword(s):  
Endothelial Cells ◽  
Umbilical Cord ◽  
Antithrombin Iii ◽  
Cultured Cells ◽  
Active Role ◽  
Human Umbilical Cord ◽  
Thrombosis Research ◽  
Natural Inhibitor ◽  
Immunofluorescent Technique ◽  
Radio Immunoassay

We have shown by immunofluorescent technique that the distribution of antithrombin III (ATIII) in human tissues was concentrated around the microvasculature of the lungs and kidneys, as well as veins and small arteries of other organs (liver and spleen). It would seem that ATIII is stored and/or synthesized in the endothelial cells similar to Factor VIII-RAG and Plasminogen Activator. Endothelial cells were isolated from human umbilical cord by collagenase and cultured according to Chemethod described by Shearn etal (1977). In freshly isolated endothelial cells, ATIII could be demonstrated by indirect immunof1uorescent technique and radio immunoassay confirmed the presence of 14.8 ng per 106 cells. After 7 days’ culture, the supernatant from 106 cells contained about 15 ng and the cultured cells (106) contained 16.9 ng ATIII. The presence of ATIII in cultured cells was also confirmed by the positive immunofluorescence. Hence the endothelial cells play an active role in preventing thrombosis by the synthesis and liberation of ATIII, the major natural inhibitor of the intrinsic pathway of Coagulation.Reference: Shearn S.A., Peake I.R., Ciddings J.C., Humphrys J. and Bloom A.L. Thrombosis Research, 11, 43, 1977.

Evaluation of coculture model composed of sinusoidal endothelial cells and small hepatocytes

2006 ◽  
Vol 39 ◽  
pp. S586
Author(s):  
H. Asamia ◽  
R. Sudoa ◽  
T. Mitakab ◽  
M. Ikedaa ◽  
K. Tanishitaa
Keyword(s):  
Endothelial Cells ◽  
Sinusoidal Endothelial Cells ◽  
Coculture Model ◽  
Small Hepatocytes
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