145 research outputs found
The effects of extremely low frequency pulsed electromagnetic field on collagen synthesis of rat skin: A biochemical and histoligical approach
The efficacious effects of pulsed electromagnetic field (PEMF) under the certain field parameters like frequency and the field intensity have been reported for various tissue and molecules. Since collagen is found abundantly in most tissue structures, this research was designed to further investigate the effects of extremely low frequency (ELF) PEMF on the synthesis of the epidermal collagen. To do the task, six groups of animals each consisting of eight mature male rats were selected randomly as one group for the control and five for the test. The field was generated by using a parallel set of Helmholtz coil. The first set of experiments was carried out at the peak intensity of 2 mT (milli Tesla) for different frequencies of 25, 50 and 100 Hz. Since the most effective frequency turned out to be 25 Hz, another set of experiment was conducted using this frequency and two different field intensities of 1 and 4 mT. The field was applied for 2.5 h/day lasting for 8 days, keeping the same procedure for the control group except for the field turned off. On the ninth day, the rats were sacrificed and the skin samples from the dorsal region were taken for biochemical assessment of collagen by measuring hydroxyproline content using Stegeman-Stalder method and histological assessment. The data indicated that pulsed electromagnetic field of 2 mT at 25 Hz increased the collagen synthesis (P<0.05). The other intensities and frequency setting did not have much distinguishable effect, however, at the frequency of 25 Hz and 4 mT, the field effect on the collagen increase was also noticeable. It was concluded that applying the field parameters of 25 Hz and 2 mT peak intensity for 2.5 h/day during eight days rendered a significant increase in collagen synthesis in rat skin. Histological observations were consistent with the biochemical findings
Effects of Cyclic Test in Decreasing Damages to Structures and Roads on Gypsum Soils
Fine gypsum soils, when saturated and loaded, because of their high porosity, have large settlements. Compaction of the soil and removal of the load causes the soil to swell. These properties of gypsum soils cause many problems for structures built on them. For instance unsymmetrical settlement, uneven ground floor and cracks in façade are some of the problems. Likewise in road engineering, swelling of this type of soil located under the asphalt after absorbing water is one of it most important problem. So realizing and identifying the behavior of gypsum soils and effort in finding solutions for decreasing the amount of settlement and swelling are the main objectives of this study. The soil samples were from the City of Mashhad, which is the second largest city in Iran. These soils naturally contain high amount gypsum and hence have a special behavior. In this study, samples with different amount of gypsum were gathered and classified to seven sample groups. Preliminary tests done showed that the increase in the amount gypsum causes the soil plasticity index and unit weight to decrease, which in turn increases settlement. In order to investigate the influence of degree of compaction, all samples were compacted with different unit weight and the swelling potential and swelling pressures were measured after saturation. The results show that with increasing unit weight and amount of gypsum, the soil swelling potential increases. Cycles of wetting and drying and also cycles of loading and unloading were performed to investigate their influence on the gypsum soil
Comparison of saccadic eye movements and facility of ocular accommodation in female volleyball players and non-players
There is controversy on the interaction of sport exercise and visual functions. Some aspects of visual skills have been evaluated in volleyball players. Eighty-three normal females were categorized in four groups; non-players (NP), beginner volleyball players, intermediate and advanced players. Facility of accommodation and far saccade for optotypes at three distances were measured. The athletes showed better facility of accommodation and saccadic eye movement (SEM) than the non-playing control group. There was a significant difference (P<0.001) between NP and beginner players with advanced players and intermediate players. There are mutual interrelations between the visual system and sensory-motor coordination of the whole body. In a "programed" activity many motor and sensorial elements interactively influence one another. The visual system, as the most important coordinator, navigates the "programed" activities. The facility of accommodation shows how fast clear vision can be accomplished. The SEM shows how fast visual system can fixate on an object. Improvement of these two parameters indicates that the visual system can change fixation very fast and clearly see a new fixation point promptly. These are the requirement for a good volleyball player; hence, we find better visual performance in advanced players than in others. Copyright © 2006 Blackwell Munksgaard
Low-power density of 950 MHz radiation does not affect long-term potentiation in rat dentate gyrus
Introduction: Over the last decade, exposure to non-ionizing electromagnetic waves due to base station antenna has increased. This in vivo study was planned for evaluating the effects of whole-body exposure to 950 MHz field of GSM mobile phone system on rat dentate gyrus long-term potentiation. Materials and methods: 24 naive male Wistar rats (3 month old, 225±25 g) were randomly divided in the three groups (sham-exposed, GSM and continuous field exposed). The exposure program was planned for 10 sessions at 3 days. Animals were exposed to electromagnetic field for 45 minutes in a circular plastic chamber (mean power density=0.835 mW/cm2). Immediately after end exposure, anesthesia was induced for long term potentiation (LTP) induction. Field potentials were recorded and analyzed using the population spike amplitude and EPSP slope for 60-min. Results; There were no significant differences in population spike amplitude, EPSP slope and EPSP slope maintenance among the three groups. Conclusion: This study provides no evidence indicating that long-term potentiation can be affected by the whole-body exposure to low-power density of 950 MHz field of GSM mobile phone System
Next Generation Simulation Tools: The Systems Biology Workbench and BioSPICE Integration
Design of a combinatorial DNA microarray for protein-DNA interaction studies
BACKGROUND: Discovery of precise specificity of transcription factors is an important step on the way to understanding the complex mechanisms of gene regulation in eukaryotes. Recently, double-stranded protein-binding microarrays were developed as a potentially scalable approach to tackle transcription factor binding site identification. RESULTS: Here we present an algorithmic approach to experimental design of a microarray that allows for testing full specificity of a transcription factor binding to all possible DNA binding sites of a given length, with optimally efficient use of the array. This design is universal, works for any factor that binds a sequence motif and is not species-specific. Furthermore, simulation results show that data produced with the designed arrays is easier to analyze and would result in more precise identification of binding sites. CONCLUSION: In this study, we present a design of a double stranded DNA microarray for protein-DNA interaction studies and show that our algorithm allows optimally efficient use of the arrays for this purpose. We believe such a design will prove useful for transcription factor binding site identification and other biological problems
Evaluation of haptoglobin phenotypes in acute myocardial infarction (AMI) and their association with some risk factors
Acute myocardial infarction (AMI) is one of the most common cardiovascular complications with a complex pathogenesis where inflammatory markers are involved in disease etiology. The aim of this study was to investigate haptoglobin phenotypes and their association with some risk factors in patients with a history of AMI. 120 patients who were referred to the emergency department of Amir Al Momenin hospital of Zahedan city, Zahedan-Iran were recruited in a cross-sectional case control study. 120 normal individuals were also chosen as controls for this study. Serum was isolated from routine bloods taken for diagnostic tests and used to determine haptoglobin phenotype distribution by electrophoresis. Phenotype differences as percent of phenotype frequency in patient and control groups were analysed using the χ2 test and SPSS software. A high frequency of serum Hp2-2 haptoglobin phenotype in patients and healthy control were found (62.5% and 58.3% respectively). A meaningful statistical correlation between high frequency of Hp2-2 haptoglobin phenotype and AMI was not found (p value = 0.484). Whereas high frequency of Hp1-1 and HP2-2 phenotypes was associated with hyperlipidemia and hypertension respectively (p value = 0.01 and 0.04). Our results showed that there was a high frequency of Hp2-2 haptoglobin phenotype in patients as well as healthy controls in the population studies. High frequencies of Hp1-1and Hp2-2 phenotypes were associated with AMI in patients with hyperlipidemia and hypertension respectively. Thus these phenotypes in AMI patients may modulate the inflammatory response in combination with hyperlipidemia and hypertension
Vaccination with human amniotic epithelial cells confer effective protection in a murine model of Colon adenocarcinoma
As a prophylactic cancer vaccine, human amniotic membrane epithelial cells (hAECs) conferred effective protection in a murine model of colon cancer. The immunized mice mounted strong cross-protective CTL and antibody responses. Tumor burden was significantly reduced in tumor-bearing mice after immunization with hAECs. Placental cancer immunotherapy could be a promising approach for primary prevention of cancer. In spite of being the star of therapeutic strategies for cancer treatment, the results of immunotherapeutic approaches are still far from expectations. In this regard, primary prevention of cancer using prophylactic cancer vaccines has gained considerable attention. The immunologic similarities between cancer development and placentation have helped researchers to unravel molecular mechanisms responsible for carcinogenesis and to take advantage of stem cells from reproductive organs to elicit robust anti-cancer immune responses. Here, we showed that vaccination of mice with human amniotic membrane epithelial cells (hAECs) conferred effective protection against colon cancer and led to expansion of systemic and splenic cytotoxic T cell population and induction of cross-protective cytotoxic responses against tumor cells. Vaccinated mice mounted tumor-specific Th1 responses and produced cross-reactive antibodies against cell surface markers of cancer cells. Tumor burden was also significantly reduced in tumor-bearing mice immunized with hAECs. Our findings pave the way for potential future application of hAECs as an effective prophylactic cancer vaccine. © 2017 UIC
Vaccination with human amniotic epithelial cells confer effective protection in a murine model of Colon adenocarcinoma
As a prophylactic cancer vaccine, human amniotic membrane epithelial cells (hAECs) conferred effective protection in a murine model of colon cancer. The immunized mice mounted strong cross-protective CTL and antibody responses. Tumor burden was significantly reduced in tumor-bearing mice after immunization with hAECs. Placental cancer immunotherapy could be a promising approach for primary prevention of cancer. In spite of being the star of therapeutic strategies for cancer treatment, the results of immunotherapeutic approaches are still far from expectations. In this regard, primary prevention of cancer using prophylactic cancer vaccines has gained considerable attention. The immunologic similarities between cancer development and placentation have helped researchers to unravel molecular mechanisms responsible for carcinogenesis and to take advantage of stem cells from reproductive organs to elicit robust anti-cancer immune responses. Here, we showed that vaccination of mice with human amniotic membrane epithelial cells (hAECs) conferred effective protection against colon cancer and led to expansion of systemic and splenic cytotoxic T cell population and induction of cross-protective cytotoxic responses against tumor cells. Vaccinated mice mounted tumor-specific Th1 responses and produced cross-reactive antibodies against cell surface markers of cancer cells. Tumor burden was also significantly reduced in tumor-bearing mice immunized with hAECs. Our findings pave the way for potential future application of hAECs as an effective prophylactic cancer vaccine. © 2017 UIC
Sequential Logic Model Deciphers Dynamic Transcriptional Control of Gene Expressions
Cellular signaling involves a sequence of events from ligand binding to membrane receptors through transcription factors activation and the induction of mRNA expression. The transcriptional-regulatory system plays a pivotal role in the control of gene expression. A novel computational approach to the study of gene regulation circuits is presented here.Based on the concept of finite state machine, which provides a discrete view of gene regulation, a novel sequential logic model (SLM) is developed to decipher control mechanisms of dynamic transcriptional regulation of gene expressions. The SLM technique is also used to systematically analyze the dynamic function of transcriptional inputs, the dependency and cooperativity, such as synergy effect, among the binding sites with respect to when, how much and how fast the gene of interest is expressed. expression and additional activities of binding sites are required. Further analyses suggest detailed mechanism of R switch activity where indirect dependency occurs in between UI activity and R switch during specification to differentiation stage. is a promising step for further application of the proposed method
- …