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.
This paper describes the development of a simple spectrophotometric determination of bismuth III with 4-(2-pyridylazo) resorcinol (PAR) in aqueous solution in the presence of cetypyridinium chloride surfactant at pH 5 which exhibits maximum absorption at 532 nm. Beer's law is obeyed over the range 5-200 µg/25 mL. i.e. 0.2-8 ppm with a molar absorptivity of 3×104 l.mol-1.cm-1 and Sandell's sensitivity index of 0.0069 µg.cm-2. The method has been applied successfully in the determination of Bi (III) in waters and veterinary preparation.
The trade war, of course, leads to a sharp tension in international relations because the economy is the lifeblood of the states. In the world of trade and economy, countries began to lean towards cooperation. Economic relations after World War II were more liberal, trade barriers were removed and global trade became more flexible and smooth
The concept of narration stems from the connotation of continuous communication through which narration is manifested as a message that is exchanged between the sender and the recipient, and that narration is an educational conceptual necessity, representing the philosophy of intellectual inclusion achieved in a direct speech to the mind, but it is encapsulated in a colorful frame that attracts the soul and attracts attention, and the graphic narration is a speech A visual based on the basis of interference and sequence of the event in weaving the elements in a consensual way through a continuous communication process that begins with the embodiment of an event - an important event - to the recipient, in which an intellectual employment
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China's economic policy and its huge capabilities operate according to an expansion strategy, especially in investing foreign projects, as the past ten years have witnessed a major development in the elements of comprehensive strength, especially in the economic field, in 2014 China launched the largest initiative in the world, represented by the Belt and Road Project (BRI), which links nearly 70 countries, through this project, a very important region has emerged, which is (the port of cadres) in Pakistan, as China has headed towards that region and given the highest importance that is in its interest in the first place regardless of the great Pakistani interest, This is consistent with its future aspirations, especially after breaking
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The research aims to find out the relationship between the medical and nursing staffing and its impact on the quality of provided health service in the Yarmouk Teaching Hospital, and to understand the nature of the relationship between doctors and nurses, it has been the adoption of cooperation and conflict Kmngaran independent knowledge of the relationship between doctors and nurses and the quality of health service as a variable certified by eating five dimensions (tangibility, reliability, safety, responsiveness, empathy). The research was adopted to collect data on the questionnaire prepared medical and nursing to the angel and adopted included Likert Quintet her, and distributed to doctors working in the Yarmouk hospital in
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International trade in services is becoming increasingly important as it is an economic activity that deals with invisible trade, which has become increasingly important in the balance of international trade. The establishment of the WTO is a starting point in international trade relations. It is responsible for all aspects of international trade, , And in view of the continued increase in international trade in services, the need for more internationally recognized rules has become more urgent, especially as it has been increasingly proven that the traditional framework of public services is inadequate to operate some of the most dynamic and innovative sectors of the economy. (GATS) to be the regulatory framework for this sector
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Dialogue is one of the pillars of character building in the television series, through which it is possible to identify the most important characteristics and traits of the personality, in addition to its ability to reveal the most important problems at all levels. The following: (How does dialogue contribute to enhancing the traits of the alienated personality?). It therefore aims to identify the effectiveness of the dramatic dialogue in enhancing the traits of the alienated personality represented by (powerlessness, isolation, meaninglessness, objectification, non-standardization and rebellion). (The traits of the alienated character, and the second is the psychological function of the dramatic dialogue), to extract from them the main
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Abstract
Epidemics that afflict humankind are descending renewed, plaguing them in the place and time they spread.
- The epidemic affects individuals and the movement of societies, and its treatment requires dealing with it according to Sharia, taking into account the current data and developments.
- Integrative jurisprudence: it is intended to know the practical legal rulings deduced from the combination of evidence of two or more sciences related to one topic related to it, and among these calamities is the Corona Covid-19 pandemic.
- It is permissible to use sterile materials that contain a percentage of alcohol in sterilizing hands and fogging places, including mosques.
T
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MO Khudhair, 2020