Periodontitis is one of the most prevalent bacterial diseases affecting man with up to 90% of the global population affected. Its severe form can lead to the tooth loss in 10-15% of the population worldwide. The disease is caused by a dysbiosis of the local microbiota and one organism that contributes to this alteration in the bacterial population is Prophyromonas gingivalis. This organism possesses a range of virulence factors that appear to contribute to its growth and survival at a periodontal site amongst which is its ability to invade oral epithelial cells. Such an invasion strategy provides a means of evasion of host defence mechanisms, persistence at a site and the opportunity for dissemination to other sites in the mouth. However, previous studies have demonstrated that invasion of the mammalian cells in a population by P. gingivalis is heterogenous, with some cells becoming heavily invaded while others harbour no or only a few bacteria. An understanding of this heterogeneity may throw light on the mechanisms involved and we hypothesised that the phase of the host cell cycle may explain this phenomenon. In an attempt to study the factors influencing P. gingivalis invasion and the cell response to that invasion, a standard antibiotic protection assay was employed and an oral keratinocyte cell line, H357. The results showed that P. gingivalis NCTC 11834 invasion was significantly increased with increasing time of exposure to the cells and the cell density. This may reflect an increased host cell surface area available for bacterial attachment. No effect on invasion of P. gingivalis invasion was observed by the bacterial growth phase, H357 cell passage number or whether cells were pre-incubated with P. gingivalis lipopolysaccharide. Epithelial cells did, however, respond to the presence of P. gingivalis in a number of ways. For example, the mRNA expression of endothelin-1 and urokinase receptor were upregulated with increasing P. gingivalis infection time, suggesting that these proteins could act as inflammatory mediators and possibly as useful markers of the severity of periodontal disease or in the diagnosis and treatment of periodontitis. iii Secondly, in an attempt to investigate the reason for the observed heterogeneous P. gingivalis invasion of H357 cell populations, the effect of cell cycle phase on P. gingivalis invasion was investigated. H357 cells were synchronized by serum starvation. On re-introduction of serum, characterisation of cell cycle phase distribution was performed by flow cytometry following staining with propidium idodide (PI) or by immunofluorescence using bromodeoxyuridine (BrdU), which specifically identifies cells in S-phase. The effect of cell cycle phases on P. gingivalis invasion was measured using the antibiotic protection assay, immunofluorescence and flow cytometry and these were correlated with gene and surface expression of the urokinase receptor and the α5-integrin subunit, which is thought to mediate P. gingivalis invasion. Results showed that the percentage invasion was enhanced with increasing serum re-introduction time, and positively correlated with the number of cells in S-phase. In addition, flow cytometry data showed that the highest association of fluorescent P. gingivalis was with PI positive S-phase cells. Moreover, BrdU positive S-phase cells were 3 times more likely to be invaded and contained 10 times more P. gingivalis than cells in other phases. Also, α5-integrin was more highly expressed in cells in S-phase than other phases, which could explain the mechanism underlying this enhanced invasion. Data presented here have suggested that P. gingivalis targeting of cells in S- phase could, in vivo, allow preferential invasion of the junctional epithelial cells which turns over rapidly. The data presented in this thesis suggest that P. gingivalis invasion is greatly dependent on several factors attributed to the host, the bacteria itself, and to the environment which the bacteria reside in. The invasion occurs within a population of host cells in a heterogeneous fashion, and is dependent on the cell cycle phase, specifically S-phase. This novel finding, in addition to the previously reported mechanisms of P. gingivalis invasion, increases our understanding of this virulence trait and suggests that such a strategy is a highly organised process which the bacteria can follow to ensure its survival within the host. Furthermore, knowledge of these mechanisms could provide novel approaches to treatment of periodontal diseases.
Abstract
This study aims to identify the repercussions of the Corona pandemic (Covid 19) and its impact on the educational and psychological functions of the Omani family from the point of view of a number of fathers and mothers. Drive for a group of fathers and mothers, some of whom work in the government sector and others are mothers enrolled in graduate studies programs at the university, their ages range between (30-50 years) totally (28) mothers and fathers: 22 mothers and 6 fathers. The results showed that the repercussions of the transformation of e-learning, home quarantine, social distancing, and the challenges associated with them were among the most frequent responses that posed a real challenge to the
... Show MoreThe love of the world and its lusts are the head of sins and the corruptors of religion, and the one who loves and loves them who prefers them over the hereafter is one of the most pitiful of creation, and the least intelligent of them, as he prefers imagination over reality, sleep over wakefulness, fleeting shadow over eternal bliss and the mortal abode over the eternal abode, and he sold the life of eternity for the most luxurious life. In life, it is dreams and sleep or as a fleeting shadow, and as it was said: The intelligent person is not deceived.
The reason for choosing this topic is due to two things:
The first: When I contemplated the reasons for the differences and conflicts that afflicted our wounded and occupied country
In the current research, multiple mixing ratios of gamma -transitions of the energy levels 60𝑁𝑑 142−150 isotopes populated in 𝑁𝑑(𝑛, 𝑛 ˊ 60 142−150 ) 60𝑁𝑑 142−150 interaction are calculated using the constant statistical tensor (CST) method. The results obtained are, in general, in good agreement or consistent, within the experimental error, with the results published in the previously researches. Existing discrepancies result from inaccuracies in the experimental results of previous works. The current results confirm the validity of the constant statistical tenser method of calculating the values of mixing ratios and its predictability of errors in experimental results
The research aims to identify the extent to which Iraqi private banks practice profit management motivated by reducing the taxable base by increasing the provision for loan losses by relying on the LLP it model, which consists of a main independent variable (net profit before tax) and independent sub-variables (bank size, total debts to total equity, loans granted to total obligations) under the name of the variables governing the banking business. (Colmgrove-Smirnov) was used to test the normal distribution of data for all banks during the period 2017-2020, and then find the correlation between the main independent variable sub and the dependent variable by means of the correlation coefficient person, and then using the multiple
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Green synthesis is depending on preparation of nano composited SiO2/V2O5 by using the modified sol-gel method depending on rice husk ash as a source for the extraction of silica gel and the product powder of nano composited SiO2/V2O5 characterization by many techniques such as X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and N2 adsorptions/desorption isotherms (BET). This study also includs the biological effectiveness of SiO2/V2O5 and its effect on inhibiting bacterial growth after the prepared nanomaterial was applied to wound dressings, which gave a promising result for its use as
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Title: Arabic Manuscript, Concepts and Terms and Their Impact on Determining Its Historical beginnings and extension of its existence.
Researcher: Dr. Atallah Madb Hammadi Zubaie.
Bn the name of Allah Most Merciful
The interest in manuscripts and rules of their investigation and dissemination appeared soon, and the speech in editing terms and concepts appeared in sooner time. When looking at the classified books in the Arab manuscripts , we find the books of the first generation did not allude definition for this term , but rather focused on the importance of manuscripts and their existence locations, indexing, care, and verification rules. The reason for this is that the science of Arabic manuscrip
... Show MoreCentral banks around the world typically use various financial indicators to evaluate performance. In Iraq, the indicators used by central banks to evaluate the performance of banks are of great importance to ensure that the banks operating within the Iraqi banking system comply with the regulatory and legal requirements issued by the Central Bank of Iraq or the Ministry of Finance. Given the need to study the profitability indicator to ensure its ability to evaluate the performance of specialized banks in Iraq, these banks carry out their banking activities and businesses through capital funded by the government. The use of profitability indicators in evaluating the performance of specialized banks provides information about the profitabil
... Show MoreThe importance of the current study lies in the importance of the Tax policy that being considered one of the most important tools working on fulfilling the social, financial and economic goals and improving the investment environment in the country to become having the ability to activate the national economy. The current study has referred that ( Has the tax planning practiced by the Iraqi contribution companies led to increase the far-term tax outcome through getting benefit of the monetary funds and expansion in&nbs
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The research topic was chosen because of the importance of communication in organizations in general and the marketing process in particular. Without communication, the organization can not live and continue ,The problem of study diagnosis the reduction in sales in the company of plant oils in some its classes and weakness in differentiation and its reputation at market in spit if having good products with standardized features And lack of customer communication channels, also the company does not have any whole view about the concept of marketing communication, Therefore, This sudy aimed ro define to know the type of relationship between the extent of the impact of the integrated marketing
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