Studies of the enzymes that convert steroid hormones in the human adipose tissue

Les tissus adipeux ont été reconnus il y a longtemps comme des sites importants de transformation et d’action des hormones stéroïdiennes. Parmi ces hormones, les androgènes et les oestrogènes jouent un rôle important dans la régulation des fonctions du tissu adipeux comme l'accumulation de triglycérides, la lipolyse, la différenciation des préadipocytes et la prolifération cellulaire. La disponibilité de ces hormones est modulée par un groupe d’enzymes de conversion des stéroïdes qui n’ont pas été entièrement caractérisées dans les tissus adipeux humains. Objectif: Notre objectif était de caractériser les isoenzymes de la 5α-réductase de même que la 17β-hydroxystéroïd déshydrogénase (17β-HSD) de type 2 et leur association avec les mesures anthropométriques et/ou les marqueurs d'adiposité. Méthodes: Des tissus adipeux omental et sous-cutané ont été obtenus auprès d’hommes et/ou de femmes non-obèses et/ou obèses. L'expression des 5α-réductases et 17β-HSD type 2 ont été mesurées dans différents modèles de tissus adipeux. Des techniques d’immunohistochimie et d'imagerie confocale ont été utilisées pour localiser la 17β-HSD type 2 dans les tissus adipeux. Nous avons utilisé des inhibiteurs spécifiques à ces enzymes dans nos expériences. De plus, des cultures de cellules HEK-293 ont été utilisées pour tester les inhibiteurs des 5α-réductases. Résultats: Nous avons démontré que la dihydrotestostérone est formée principalement à partir de l'androsténedione (4-dione) et est responsable de la grande majorité de l’effet inhibiteur du 4-dione et de la testostérone sur l'adipogenèse. Les isoenzymes de la 5α-réductase jouent donc un rôle important dans la régulation de la différenciation des préadipocytes. Nos résultats indiquent également que la conversion de la testostérone et de l'estradiol en stéroïdes moins actifs tels que le 4-dione et l'estrone, respectivement, est effectuée par la 17β-HSD type 2 qui est localisée dans les vaisseaux sanguins des tissus adipeux des hommes et des femmes. Conclusion: Les 5α-réductases et la 17β-HSD type 2 modulent la disponibilité des hormones stéroïdiennes actives dans les tissus adipeux humains. Leur activité et/ou leur expression est associée aux mesures d’adiposité. Ceci supporte la notion d’un rôle possible de ces enzymes dans l'altération des dépôts graisseux via une modulation de la disponibilité des hormones stéroïdiennes actives.Adipose tissue has long been recognized as a significant site for steroid hormone transformation and action. These hormones include androgens and estrogens, which play a pivotal role in the regulation of many adipose tissue functions including triglyceride accumulation, lipolysis, preadipocyte differentiation and proliferation. The availability of these hormones is regulated through a group of steroid hormone-converting enzymes that have not been fully characterized in adipose tissue. Our objective was to characterize steroid hormone-converting enzymes 5α-reductase and 17β-hydroxysteroid dehydrogenase (17β-HSD) type 2 and their involvement in the regulation of androgen and estrogen availability in abdominal adipose tissues of men and/or women, and define their association with anthropometric measurements or other adiposity markers. Methods: Omental (OM) and subcutaneous (SC) adipose tissues were obtained from non-obese and/or obese men and/or women. The expression of 5α-reductase and 17β-HSD type 2 isoenzyme was measured in various OM and SC tissue models. Immunohistochemistry and confocal imaging techniques were used to localize 17β-HSD type 2 in adiposes tissues. We used specific enzyme inhibitors in our experiments. In addition, HEK-293 cell cultures were used to test the 5α-reductase isoenzymes inhibitors. We also measured glycerol-3-phosphate dehydrogenase (G3PDH) activity with or without 5α-reductase inhibitors to assess the extent of preadipocyte differentiation. Results: Dihydrotestosterone is formed mainly through 4-androst-4-ene-3,17-dione (4-dione) and it is responsible for the vast majority of the inhibitory effect of 4-dione and testosterone on adipogenesis. 5α-reductase isoenzymes play an important role in the regulation of preadipocyte differentiation through modulation of androgenic activity. Our results also indicated that the conversion of testosterone and estradiol into less active steroids such as 4-dione and estrone, respectively, is caused by 17β-HSD type 2, which is localized in the blood vessels of adipose tissue in both men and women. No sex difference was detected in HSD17B2 mRNA expression. However, opposite correlations were found between 17β-HSD type 2/HSD17B2 mRNA expression and/or activity with age or adiposity measurements in both sexes. Conclusion: 5α-reductases and 17β-HSD type 2 have opposite actions on the availability of active steroid hormones in human OM and SC adipose tissues. The activity and/or the expression of these enzymes is associated with adiposity measurements. This supports a possible role of these enzymes in altering fat deposition through the modulation of active steroid hormone availability in adipose tissue

Preprocessing of microcirculatory images.

This thesis project consists of the development of a computerized image processing system to preprocess microvascular images of the mouse Latisimus Dorsi Muscle (LDM). This research has been conducted in association with the Division of Plastic and Reconstructive Surgery at the University of Louisville. The input to the system is a set of 35 or more overlapping microscopic fields or sub_images containing segments of the LDM microcirculation, the output is an adjacent single montage encompassing the entire LDM microvasculature. The developed system presents practical solutions to the problems of image registration, overlap resolution, and image segmentation, in addition, the results of this project include simple geometrical measurements of the microvascular system such as length, tortuosity, and directionality. In future projects, the measurements should be further analyzed to study the LDM microcirculation. The entire system was written in C/C++ languages, and the Bluestone\u27s UIM/X GUI builder. The system was implemented on the Speed School\u27s HP-9000 Unix system. The system also takes advantage of the image processing libraries (ImageMagick) available on the system

Equation of State

An equation of state (EOS) is a thermodynamic expression that relates pressure (P), temperature (T), and volume (V). This equation is used to describe the state of reservoir fluids at given conditions. The cubic equations of state (CEOS) such as Van der Waals, Redlich-Kwong, Soave, and Peng-Robinson are simple models that have been widely used in the oil industry. This chapter expressed literature for EOS that varies from simple expressions to multiple constant and convoluted types of equations. Many attempts have been made to describe the thermodynamic behavior of fluids to predict their physical properties at given conditions. So, several forms of the equation of state have been presented to the oil industry in order to calculate reservoir fluid properties. The heat exchanger is important in wildly fields as in aerospace, petrochemical industry, refrigeration, and other fields. The optimization design of the heat exchanger is a great significance to industry process to reduce production cost, realize energy conservation, and reduce energy consumption

Functions and contextual triggers of offensive language on Twitter

The use of social media in daily life is dramatically increasing all over the world and microblogging websites, particularly Twitter, have become widespread and excessively used. These web-based mediums of communication host significant social interaction and distinctive user-generated content that are characterized by the use of unique lexical choices and structures. This has led to emergent and diversified research investigating how different the linguistic behavior on these web-based platforms is from other forms of interactions. A controversial linguistic phenomenon on social media is the use of offensive language, which is on the increase and suggests a new domain of linguistic research to answer many questions that have arisen in light of this phenomenon. This phenomenon applies to many languages one of which is Arabic, especially where colloquial Arabic is concerned. This study examines the expressive functions of offensive language on Twitter which were written in Arabic by Egyptians. It also examines the pragmatic categories utilized when this offensive language occurs, as well as the contextual triggers of this type of language. A large purposeful sample of 482 tweets was collected from the Twitter website from different Egyptian tweeps writing in colloquial Arabic. Based on Culpeper\u27s (2010) impoliteness formulae, the collected data was classified into four pragmatic categories: insults, pointed criticism or complaints, negative expressives, and challenging or unpalatable questions. The results show that the offensive language used on Twitter serves expressive functions such as hate, anger, and sarcasm. The results also show that the most common contexts that trigger this offensive use of language are political, economic, personal, and soccer games. The study concludes that the use of offensive language on Twitter has become conventionalized and accepted by this speech community

Attitudes towards distance Learning in Morocco within Covid 19: Public High School Teachers and Students as a Case Study

This study investigates Moroccan EFL Students and teachers attitudes towards distance learning The study tackles students learning using Miscrosoft teams their knowledge about the platform and the efficiency of this new teaching tool to satisfy their learning needs The enquiry exerts a quantitative method using a questionnaire to collect data The questionnaire was administered to Ibnu Elhaytham High school teachers and students Kenitr

The International Multilateral System: Imperatives of Change, Potential Scenarios and Suggestions for the Future

Thesis presented to satisfy the necessary requirements for obtaining a PhD degree in International Relation with specialization in Globalization and the Environment,This research on the international multilateral system has its raison-de-être in the problems of lack of effective global governance manifested in areas such as global politics, security, economy, environment and others. A fundamental focus of the research is on the latest changes in world politics, including state power shifts, power diffusion from state to non-state actors and the implications of the rapid evolution of globalization over the last two decades, with its proliferating challenges and opportunities. In addition, the research examines reform efforts in multilateral institutions and some of the reform proposals suggested in academic circles. The main objective of the research is to provide a holistic analysis of the current state of the multilateral system, the imperatives of reform in the system, its potential future scenarios as well as some suggestions for the future. No doubt, the United Nations (UN) is the core hub of the current system. Hence, the research principally approaches its subject from the perspective of the UN. In particular, the UN General Assembly is the subject of a case study that aims, among others, to highlight the predicament and potential of this unique forum of multilateral cooperation