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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Efeitos do Enalaprilato em equinos desidratados por poli?ria e restri??o h?drica / Effects of enalaprilat in horses dehydrated by polyuria and fluid restriction

OLIVEIRA, Gabriela Ferreira 12 August 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-10-16T18:19:32Z No. of bitstreams: 1 2013 - Gabriela Ferreira de Oliveira.pdf: 1149006 bytes, checksum: e5df0fd5e246ea685fd7bb50c7ab42d5 (MD5) / Made available in DSpace on 2018-10-16T18:19:32Z (GMT). No. of bitstreams: 1 2013 - Gabriela Ferreira de Oliveira.pdf: 1149006 bytes, checksum: e5df0fd5e246ea685fd7bb50c7ab42d5 (MD5) Previous issue date: 2013-08-12 / Sodium is the major electrolyte of the extra cellular space, essential for the control of plasma osmolality and blood pressure. In addition, sodium is the only mineral for which there is a defined appetite. For sodium homeostasis and for the regulation of extra cellular fluid, the reported physiological systems include the renin angiotensin aldosterone system, atrial natriuretic peptide and oxytocin. In mice the feeding behavior of sodium is well established and the central inhibition of sodium appetite has been demonstrated. However, in some domestic species, especially in horses, subject of this study, this behavior has not yet been clarified. This study aimed to evaluate the clinical and hematological effects, beyond the assessment of fluid and electrolyte balance and feeding behavior of fluids after the central administration of enalaprilat in horses experimentally dehydrated. Six adult, gelding horses, were used. The animals were subjected to water and food restriction for 72 hours prior the study, associated with the administration of three doses of furosemide in the first 24 hours. After the 72 hours fasting, the animals were divided into two experimental groups. The first group was called Control Group (CG) and the second, Treaty Group (TG). The animals of TG received 2.75 mg/animal of enalaprilat by intracarotideal route. After administration of enalaprilat, the animals had free access to water and hypertonic saline solution (1.8% of NaCl), with ingested volumes monitored. All animals were submitted to a regular and periodical physical examination, measured blood pressure and collected blood samples every 12 hours until the administration of enalaprilat, to evaluate the effects of dehydration; and 30, 60, 120, 180 minutes and 24 hours after administration, to evaluate the drug effects. Weight loss was the parameter that best reflected dehydration, which was estimated at 10.5% at the end of 72 hours of food and water restriction. When the animals had free access to water and saline, we observed a higher total water consumption in TG (13.7 ? 12 L) than in the CG (9.1 ? 7.9 L), with no significant difference between groups (p = 0.3522). There was no significant difference between GC and GT in clinical and hematological parameters, in all moments evaluated. Evaluating the sodium appetite, as evidenced by the ratio between salt intake and the amount of fluid consumed, it was observed that the TG showed lower sodium appetite than the CG (p = 0 0396), observed 120 minutes after the central administration of enalaprilat, demonstrating the centrally action of ACE inhibitor (enalaprilat) in inhibition of sodium appetite in horses. / O s?dio ? o principal eletr?lito do espa?o extracelular, fundamental para o controle da osmolaridade plasm?tica e press?o arterial, al?m de ser o ?nico mineral para qual existe um apetite claramente definido. Para a homeostase do s?dio e do fluido extracelular, os sistemas fisiol?gicos relatados incluem o sistema renina angiotensina aldosterona (SRAA), pept?deo natriur?tico atrial (ANP) e ocitocina (OT). O comportamento ingestivo de s?dio em ratos j? est? bem estabelecido e a inibi??o central do apetite por s?dio j? foi demonstrada. Por?m, em algumas esp?cies dom?sticas, especialmente nos equinos, tema deste trabalho, este comportamento ainda n?o foi esclarecido. O objetivo deste trabalho foi avaliar os efeitos cl?nicos e hematol?gicos, al?m da avalia??o do equil?brio hidroeletrol?tico e do comportamento ingestivo de l?quidos ap?s a administra??o central de enalaprilato em equinos experimentalmente desidratados. Foram utilizados seis equinos adultos, machos, castrados, que permaneceram em jejum h?drico e alimentar por 72 horas, associado ? administra??o de furosemida. Ap?s 72 horas de jejum, os animais foram divididos em dois grupos experimentais, o Grupo Controle (GC) e o Grupo Tratado (GT), que recebeu 2,75 mg/animal de enalaprilato por via intracarot?dea. Ap?s, os animais tiveram livre acesso a ?gua e a solu??o salina hipert?nica (1,8% de NaCl). Os animais foram avaliados atrav?s de exame cl?nico, a cada 12 horas durante as 72 horas de jejum e 30, 60, 120, 180 minutos e 24 horas ap?s o Enalaprilato. Foram avaliados o peso corporal, a quantidade de l?quidos ingeridos, a press?o arterial m?dia, par?metros bioqu?micos e eletrol?ticos sangu?neos. A perda de peso corporal foi o par?metro que melhor refletiu a desidrata??o, estimada em 10,5% ao final de 72 horas de jejum. Com o restabelecimento do acesso ? ?gua e solu??o salina, observou-se maior consumo total de ?gua no GT (13,7 ? 12 L) que no GC (9,1 ? 7,9 L), sem diferen?a significativa entre os grupos (p = 0,3522). N?o houve diferen?a significativa nos par?metros cl?nicos e hematol?gicos avaliados entre o GC e o GT. O apetite por s?dio foi reduzido significativamente (p = 0, 0396) no GT comparado ao GC, evidenciado 120 minutos ap?s a administra??o do enalaprilato, demonstrando a a??o central do inibidor de ECA (Enalaprilato) na inibi??o do apetite por s?dio em equinos.
132

藏戲《諾桑王傳》人神關係之分析 / The Analysis of the Relations Between Human and God in ace- lhamo"chookee-norsan"

鄭怡甄, Cheng, Yi-Chen(Jean) Unknown Date (has links)
本論文研究藏戲《諾桑王傳》的文本及演出之形成與發展,瞭解其作 為藏族八大藏戲中年代最久遠,流傳範圍最廣,專門演出劇團最多,影響藏戲演出藝術最深,且與藏族文化中的歷史,宗教,文學密不可分的性質後;以《 諾桑王傳》故事乃藏族文化的縮影,以藏戲《諾桑王傳》的演出為藏族凝聚彼此的中介活動之觀點出發;分析本劇中人神關係發生的場景,情節架構,角色類型,事件活動,以建構出藏族文化的內在結構與內涵. 筆者分析出本劇中的變化,對立,排列,及相互連繫的四種人神關係後,對藏傳佛教中苯教與佛教的融合狀況,及對藏族文化中人與苯教神靈,佛教神靈間的交互作用,都有較具體與整合的概念;在此研究基礎上,筆者圖示出佛陀,菩薩,世間大神,地方神,家神的五個藏傳佛教神靈體系,另外並圖示包含大活佛,高級僧人,及最低一等的一般僧人,平民百姓,低賤階級,共三階層的人的體系.故本論文將提供未來藏傳佛教研究者一個參考範例. / The study of the thesis is on the Tibetan opera"chooee- norsan".It spreadingage long and widely.It also has the most many theatrical companies in Tibet,and it has a profound influence on performance art.Besides,it has a deep connection with the history,religion,literature of the Tibet.So,the story is a miniature of Tibetan culture.The present is a liminal activity to curdle the society with these point of view,I analysis the stage,the structure of the plot,the style of role, the activity of the events,and find out four relations between human and god.There are change,oppsite,series,and connection. They build the interior structure and contents of the Tibetan culture.
133

Prescribing patterns of angiotensin-converting enzyme inhibitors for the period 2001 until 2006 / Lourens Johannes Rothmann

Rothmann, Lourens Johannes January 2007 (has links)
Thesis (M.Pharm. (Pharmacy Practice))---North-West University, Potchefstroom Campus, 2008.
134

A.C.E.-pedagogiken med sikte på religionsundervisningen

Sewón, Katarina January 1993 (has links)
Jag har genomfört en studieresa till A.C.E.-Tabor, Danmark, där jag studerat en annorlunda pedagogik, A.C.E. (Accelerated Christian Education), som bygger på individualiserad undervisning med eleven i centrum och där eleven själv sätter sina studiemål. Det som särskilt väckt mitt intresse är att man utgår från bibeln i undervisningen och försöker lära eleverna efterfölja Jesu karaktärsdrag, som avspeglas i undervisningsmaterialet och lärarnas förhållningssätt. Jag har försökt finna idéer och tankar inom pedagogiken som skulle kunna berika vår religionsundervisning. För att få en bild av hur religionsundervisningen bedrivs i dagens svenska skolor, har jag använt mig av en enkät, som låg- och mellanstadielärare fått besvara. Av enkäten framgår det att så gott som alla lärare använder sig av bibeln i undervisningen, främst som uppslagsbok för egen förberedelse och för att visa omfång och uppläggning. Etik och moral anses viktigt, men många skulle gärna ha mer kunskap i ”ämnet”. / Examensarbete på Grundskollärarlinjen med inr mot åk 1-7 ht 1993.
135

Synthetic Investigations In Terpenoids And Steroids

Bijoy, P 07 1900 (has links)
The thesis entitled "SYNTHETIC INVESTIGATIONS IN TERPENOIDS AND STEROIDS" consists of 3 Chapters Chapter-I deals with the synthetic studies on the hexacyclic nortriterpene Pfaffic acid 1, and is divided into two sections. Section-I begins with a brief introduction to Pfaffic acid 1, a naturally occurring hexacyclic nortriterpene, in particular to its isolation, structural elucidation and antitumor activity. The antitumor activities of the Pfafosides A, B, C, D, E and F, the glycosides of pfaffic acid 1, isolated from the same plant is also described. The discussion presents the synthetic strategy developed to construct the AB ring system along with the results of the attempted synthesis of DEF ring of Pfaffic acid 1. The retrosynthetic analysis of 1 identified the key intermediates as AB synthon 2, and the DEF synthon 3, Regioselective hydride reduction of Wieland-Mischer ketone, followed by hydroxyl protection and Woodward methylation gave the dimethylated compound 4 Deprotection of the hydroxyl group and reduction of the carbonyl followed by acetylation resulted in the diacetate 5 Oxidation of the diacetate 5 with PDC-/BuOOH-celite system followed by lithium-liquid ammonia reduction yielded the saturated keto diol 6, which on dehydration and subsequent acetylation afforded the enone acetate 2, which formed the AB ring of Pfaffic acid 1 The synthetic studies towards the construction of DEF rings of Pfaffic acid commenced with the preparation of the indane methanol 7 The alcohol 7 was synthesized starting from 5-methoxyindan-l-one Thus 5-methoxyindanone was converted into the hydroxymethyl compound 8 by Wittig reaction and subsequent hydroboration Swern oxidation of 7, followed by methylation and reduction resulted in the indane methanol 7 Lithium-ammonia reduction of 7 gave a dihydrocompound, which on hydrolysis with oxalic acid gave the isomeric enones 9 and 10 in 1 1 ratio On the other hand, hydrolysis of the dihydrocompound with 5N HC1 in methanol afforded the isomers 9 and 10 in 85 15 ratio Addition of KCN to the isomeric enone mixture (85 15) resulted in the lactone 11 in 60% yield.The formation of the lactone 11 clearly established that the major isomer of the mixture has the angular hydrogen and hydroxymethyl group in as orientation as represented in 9, but unfortunately this geometry is unfavorable for the construction of the DEF ring of Pfaffic acid Similar Birch reduction of the alcohol 8 gave the corresponding dihydrocompound, which on hydrolysis with 5N HC1 in methanol afforded the isomeric alcohols 12 and 13 in 92 8 ratio Hydrogenation of the mixture followed by tosylation yielded the tosylates 14 and 15 in the same ratio Attempted intramolecular cyclisation of the tosylate mixture with different bases failed to yield any tricyclic compound, indicating that the major isomer has the unfavorable geometry for intramolecular alkylation. The origin of stereoselectivity during the hydrolysis of the enol-ether leading to the formation of the isomers 9 and 12 in major amount, was found to be due to a novel hydroxyl directed protonataon as represented in 16 Section-ll describes a novel oxidative C-C bond cleavage reaction with chromium reagents The alcohol 8 when oxidized with a variety of chromium reagents gave 5-methoxyindan-1-one in good yields. The mechanism of this reaction seems to go via the enol 17, which undergoes C-C bond cleavage to afford 5-methoxyindan-l-one. A number of 1-hydroxymethyl indanes 18 and 1-hydroxymethyl tetralins 19 were synthesized and their oxidation with PCC and PDC was examined In all these cases a smooth C-C cleavage was observed resulting in the respective aryl ketones Chapter-II deals with the synthetic investigations on the construction of the tricyclic ACE synthon 20, a potential intermediate for the synthesis of A-ring aromatic steroids, and is divided into two sections. Section-] describes the literature pertaining to the synthetic approaches towards A-ring aromatic steroids, with the emphasis being a critical analysis of the methodologies developed for estrone. Section-ll is divided into two parts Part-I presents the results of the synthetic studies on the construction of the tricyclic ACE synthon 20 The section starts with a need to develop a convenient methodology for the synthesis of aryltetralin 21 The new process developed for the synthesis of 21 involved a one pot Friedel-Crafts arylation of the 7-methoxy-l-tetralol 22 with the phenol to afford the aryltetralin 21 in high yield This methodology was extended to the synthesis of a number of aryl tetralins 22 to show the generality of this reaction Benzylic oxidation of the acetate of 21, afforded the aryl ketone, which on hydrolysis followed by benzylation with yielded the tetralone 24 Wittig olefination of the tetralone 24, followed by hydroboration afforded the hydroxymethyl compound 25 Swern oxidation of the hydroxymethyl compound 25 and subsequent methylation and sodium borohydride reduction gave the aryltetralin 26 along with its isomer 27 Both these isomers were separated by column chromatography over silica gel and subjected to hydrogenation to afford isomeric diols 28 and 29 Birch reduction of 28 afforded the dihydrocompound, which on acid hydrolysis resulted in a mixture of compounds consisting of 30, 31, 32, and 33 The diastereomeric isomers 30 and 31 were separated together from the other set of diastereomeric isomers 32 and 33 by column chromatography over silicagel, but the individual diastereomers could not be separated On the other hand hydrolysis of the dihydrocompound for a longer period (24 h) yielded the compound 32 as a single isomer along with the mixture 30 and 31 Part-II describes a new synthetic methodology for the construction of bicyclo[3 2 2]nonanes, During the preparation of the aryltetralin derivative 28, a hitherto unknown double Friedel-Crafts reaction, leading to the formation of bicyclo[3.2 2]nonane derivative was observed The diol 35 on treatment with phenol and A1C1, unexpectedly underwent a novel double Friedel-Crafts reaction to afford the bicyclo[3 2 2]nonane derivative 36 The mechanism of this reaction was found to go via the aryl tetralin 28 and the generality of this reaction was demonstrated by the synthesis of different aryltetralin derivatives 37, by reacting the diol with various arylating agents Chapter-III deals with the direct conversion of 130-alkylgona tetraenes into 19-nortestosterone derivatives Birch reduction of 8-dehydroestradiol-3-methyl ether 38 and 9(11)-dehydroestradiol-3-methyl ether 39 followed by acid hydrolysis results in a mixture of 19-nortestosterone 40 and retro-19- nortestosterone 41 in varying amounts However, reduction of the acetates of 38 and 39 with sodium or lithium, in the presence of aniline affords exclusively 19-nortestosterone 40 Similarly the acetate of 42 was converted to 18-homo-19-nortestosterone 43
136

Prescribing patterns of angiotensin-converting enzyme inhibitors for the period 2001 until 2006 / Lourens Johannes Rothmann

Rothmann, Lourens Johannes January 2007 (has links)
Thesis (M.Pharm. (Pharmacy Practice))---North-West University, Potchefstroom Campus, 2008.
137

Έκφραση πολυπεπτιδίων των καταλυτικών τομέων του μετατρεπτικού ένζυμου της αγγειοτενσίνης-Ι και μελέτη της δομής αυτών σε διάλυμα

Βαμβακάς, Σωτήριος-Σπυρίδων 24 February 2009 (has links)
Το μετατρεπτικό ένζυμο της αγγειοτενσίνης (ACE) είναι μία διπεπτιδυλκαρβοξυπεπτιδάση ψευδαργύρου που ανήκει στην οικογένεια των gluzincin πεπτιδασών της οποίας η θερμολυσίνη θεωρείται ως πρωτότυπο μέλος. Το ένζυμο πήρε το όνομά του από τη δυνατότητά του να μετατρέπει το βιολο- γικώς ανενεργό δεκαπεπτίδιο αγγειοτενσίνη-Ι στο οκταπεπτίδιο αγγειοτεν- σίνη-ΙΙ, το οποίο εμφανίζει ισχυρή αγγειοσυσπαστική δράση. Μία άλλη βασική δυνατότητα του ACE είναι η αδρανοποιήση του εννεαπεπτιδίου βραδυκινίνη που έχει αγγειοδιασταλτική δράση. Αυτές οι δύο σημαντικές ιδιότητες του ACE το καθιστούν ένα από τα σημαντικότερα συστατικά του συστήματος ρενίνης-αγγειοτενσίνης-αλδοστερόνης. Υπάρχουν δύο ισομορφές του ACE που μεταγράφονται από το ίδιο γονίδιο κατά τρόπο ιστοειδικό. Η σωματική ισομορφή του ACE, η οποία εμφανίζεται στην επιφάνεια των ενδοθηλιακών κυττάρων, είναι μία γλυκοπρωτεΐνη η οποία αποτελείται από μία ενιαία, πολυπεπτιδική αλυσίδα 1306 αμινοξέων. Η σπερματική ισομορφή που εμφανίζεται στους όρχεις και στα κύτταρα σπέρματος είναι μία χαμηλότερης-μοριακής μάζας γλυκοπρωτεΐνη 732 αμινοξέων. Η σωματική ισομορφή αποτελείται από δύο ομόλογες περιοχές (περιοχή Ν και C). Κάθε περιοχή περιέχει ένα ενεργό κέντρο με ένα συντηρημένο δεσμευτικό μοτίβο ψευδαργύρου HEXXH, όπου οι δύο ιστιδίνες είναι οι δύο πρώτοι υποκαταστάτες του ιόντος ψευδαργύρου. Μετά από 24 αμινοξέα στην αλληλουχία του μορίου, βρίσκεται ένα γλουταμινικό οξύ που είναι ο τρίτος υποκαταστάτης του ιόντος ψευδαργύρου. Η ύπαρξη αυτών των Ν- και C- περιοχών είναι πιθανότατα το αποτέλεσμα ενός αρχέγονου γεγονότος διπλασιασμού γονιδίων το οποίο έλαβε χώρα κατά την διάρκεια της εξέλιξης των σπονδυλωτών. Οι δύο περιοχές εμφανίζουν εκλεκτικότητα έναντι διαφόρων υποστρωμάτων, αναστολέων και διαφορές στην απαιτούμενη συγκέντρωση ιόντων χλωρίου προκειμένου να έχουν καταλυτική δραστικότητα. Υπάρχουν δύο υποστρώματα τα οποία εμφανίζουν εκλεκτικότητα έναντι του Ν-ενεργού κέντρου: το Ν-ακετυλ-σερυλασπαραγυλο-λυσυλ-προλυλ πεπτίδιο, το οποίο ρυθμίζει τη διαφοροποίηση και τον πολλαπλασιασμό των πολυδύναμων αιμοποιητικών κυττάρων και το πεπτίδιο αγγειοτενσίνη-(1-7) που είναι το αποτέλεσμα της δράσης της βραδυκινίνης. Αφ' ετέρου, τα ενεργά κέντρα και των δύο περιοχών καταλύουν την υδρόλυση της αγγειοτενσίνης-Ι και τη βραδυκινίνης με παρόμοια αποτελασματικότητα. Εντούτοις, η αναστολή του Ν-ενεργού κέντρου με το φωσφινικό πεπτίδιο RXP407 δεν έχει καμία επίδραση στην ρύθμιση της αρτηριακής πίεσης. Διαγονιδιακά ποντίκια τα οποία εκφράζουν μόνο το Ν-ενεργό κέντρο εμφανίζουν φαινότυπο παρόμοιο με αυτόν που εμφανίζεται σε ποντίκια στα οποία το γονιδίο του ACE έχει απαλειφθεί πλήρως. Κατά συνέπεια, το C-ενεργό κέντρο φαίνεται να είναι απαραίτητο και σημαντικό για τον έλεγχο της αρτηριακής πίεσης και της καρδιαγγειακής λειτουργίας. Η σπερματική ισομορφή του ACE είναι πανομοιότυπη με την C-περιοχή της σωματικής εκτός από μία μοναδική ακολουθία 36 αμινοξέων που βρίσκεται στο Ν-τελικό άκρο του. Επίσης έχει αποδειχθεί ότι η σπερματική ισομορφή του ACE διαδραματίζει σημαντικό ρόλο στην ωρίμανση του σπέρματος και στη δέσμευση αυτού στο επιθήλιο του ωαγωγού των ωοθηκών. Ο στόχος αυτής της διατριβής ήταν α) η υπερέκφραση, σε βακτηριακά κύτταρα, ο καθαρισμός και η λήψη σε διαλυτή μορφή δύο πεπτιδίων του ACE μεγέθους 108 αμινοξέων(Ala361-Gly468 (ACE_N), Ala959-Ser1066 (ACE_C)). Αυτή η πειραματική προσέγγιση επελέγη λόγω της ευκολίας χειρισμού και καλλιέργειας που εμφανίζουν τα βακτηριακά κύτταρα και λόγω της δυνατότητας της χρήση επισημασμένων με 15Ν ή/και 13C θρεπτικών μέσων. β) Η κατοχή ενός τόσο μεγάλου πεπτιδίου σε διάλυμα, επισημασμένο ή μη, δίνει τη δυνατότητα μελέτης του ως προς τα δομικά χαρακτηριστικά του χρησιμοποιώντας τη φασματοσκοπία κυκλικού διχροϊσμού ή/και πυρηνικού μαγνητικού συντονισμου (NMR). Τα προαναφερθέντα πρωτεϊνικά τμήματα υπερεκφράστηκαν σε βακτηριακά κύτταρα και ελήφθησαν σε καθαρή μορφή. Η καθαρότητά τους ήταν μεγαλύτερη από 99%. Η απόδοση για το πρωτεϊνικό τμήμα ACE_N ήταν 9mg και για το πρωτεϊνικό τμήμα ACE_C ήταν 6mg από 1L καλλιέργειας βακτηριακών κυττάρων. Τα τμήματα αυτά μελετήθηκαν ως προς την δευτεροταγή τους διαμόρφωση με φασματοσκοπία κυκλικού διχρωϊσμού. Τα αποτελέσματα της μελέτης αυτής έδειξαν ότι παρουσία 1,1,1-τριφθοροαιθανόλης, σε συγκέντρωση μεγαλύτερη από 60% και τα δύο τμήματα λαμβάνουν διαμόρφωση η οποία βρίσκεται σε συμφωνία με τη θεωρητικώς υπολογιζόμενη και με αυτή που έχει βρεθεί από κρυσταλλογραφικές μελέτες του ενζύμου. Το αποτέλεσμα αυτό μερικώς επιβεβαιώθηκε για το πρωτεϊνικό τμήμα ACE_N με τη μελέτη αυτού με φασματοσκοπία Πυρηνικού Μαγνητικού Συντονισμόυ. Η πλήρης επιβεβαίωση δεν κατέστει δυνατή λόγω της αδυναμίας λήψης καλής ποιότητας φάσματος 2D-NOESY. Συμπερασματικά, η περιγραφόμενη σε αυτή τη Διατριβή μεθοδολογία εμφανίζει πλεονεκτήματα όσον αφορά την ταχύτητα παραγωγής, τη δυνατότητα καθαρισμού των παραγομένων πεπτιδίων, καθώς και καλή επαναληψιμότητα. Οι in vitro επαναδιατεταγμένες ανασυνδυασμένες πρωτεΐνες εμφάνισαν χαρακτηριστικά δευτεροταγούς δομής, όμοια σχεδόν με αυτά που έχουν αποκαλυφθεί από την κρυσταλλογραφική μελέτη του ACE, έχοντας υψηλό ποσοστό σε α-έλικα. Κατά συνέπεια, αυτή η μελέτη περιγράφει ένα αποτελεσματικό σύστημα για την παραγωγή μεγάλων ποσοτήτων καθαρών πεπτιδίων του ACE που μπορούν να χρησιμοποιηθούν για διάφορες μελέτες. / Angiotensin converting enzyme (ACE) is a gluzincin zinc dipeptidyl carboxypeptidase I, of which thermolysin is considered the prototypical member. This enzyme took its name from its ability to convert the decapeptide Angiotensin-I to octapeptide Angiotensin-II, which is a highly potent vasoconstrictor. Another basic ability is to inactivate bradykinin, a vasodilatory peptide. These two major activities render ACE through the renin– angiotensin–aldosterone system. There are two isoforms of ACE that are transcribed from the same gene in a tissue-specific manner. Somatic ACE, which is present in brush-border epithelial cells and endothelial cells, exists as a glycoprotein composed of a single, large polypeptide chain of 1,306 amino acids, whereas in sperm cells it is a lower-molecular-mass glycoform of 732 amino acids. The somatic form consists of two homologous domains (N and C domain). Each domain contains an active site with a conserved HEXXH zinc binding motif, where the two histidines are zinc ligands, with a glutamate 24 residues downstream forming the third ligand. These N- and C-domains most likely are the result of an ancient gene duplication event that occurred during vertebrate evolution. The two domains differ in their substrate specificities, inhibitor, chloride activation profiles, and physiological functions. There are two N-domainspecific substrates: the peptide N-acetyl-serylaspartyl-lysyl-proline, which regulates haematopoietic stem cell differentiation and proliferation; and the bradykinin-potentiating peptide angiotensin-(1-7). On the other hand, the active sites of both domains catalyse the hydrolysis of angiotensin I and the vasodilator bradykinin with similar efficiency. However, inhibition of the N domain with a phosphinic peptide RXP407 has no effect on blood pressure regulation and expression in transgenic mice of the N domain alone produces a phenotype similar to that seen in complete ACE knockout mice. Thus, the C domain seems to be necessary and sufficient for controlling blood pressure and cardiovascular function, suggesting that the C domain is the dominant angiotensin-converting site. Testis ACE is identical to the Cterminal half of somatic ACE, except for a unique 36-residue sequence constituting its amino terminus. It has also been shown that testis ACE is thought to play a role in sperm maturation and the binding of sperm to the oviduct epithelium. Objective of this thesis was the overexpression, in bacterial cells, purification and solubilazation of two ACE peptides of 108 aa (Ala361-Gly468 (ACE_N), Ala959-Ser1066 (ACE_C)). This experimental approach was chosen because of the ease of culturing bacterial cells and the advantage of using label mediums with 15N and/or 13C. Such large peptides labelled or nonlabelled, can be studied for their structural features using circular dichroism and/or NMR spectroscopy. The above mentioned protein fragments overexpressed in bacteria and purified. Their purity was greater than 99%. The yield was 9mg for ACE_N and 6mg for ACE_C protein fragment from 1L bacterial culture. Their secondary structure was studied using circular dichroism spectroscopy. Deconvolution of ACE_N and ACE_C CD spectra had shown that the presence of trifluoroethanol, at concentrations of 60% or higher, is necessary for the correct folding of the protein. This result was partially confirmed for ACE_N protein fragment by Nuclear Magnetic Resonance spectroscopy. Complete conformation was not succeded due to the inability of recording the 2DNOESY spectrum of ACE_N. Conclusively, the described procedure in this research proved to be advantageous in speed and facility of purification. It demonstrated good reproductively for ACE peptides during purification. The in vitro refolded recombinant proteins had almost identical secondary features compared with these found using crystallographic data, with a high content in a-helix secondary structure motif. Thus, this study offers an effective system for producing large amounts of pure ACE peptides which can be used for several studies.
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Conception et synthèse d'inhibiteurs doubles des enzymes de conversion de l'endothéline et de l'angiotensine : synthèse stéréosélective d'acides pipécoliques polysubstitués

Riber, Ludivine January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
139

An evaluation of the Accelerate Christian Schools for reaching children for the Kingdom of God as part of Missio Dei in South Africa / Jones D.J.C.

Jones, Dina Johanna Christina. January 2011 (has links)
Secularist views are a challenge to the field of religious education. Their worldview and influence in society will be discussed. This study evaluates the theocratic model under the apartheid regime, the co–operative model and the religion policy under the new democratic government. The areas that the researcher investigated in this study are centred on the effectiveness of the mission calling of the School of Tomorrow, Accelerated Christian Education. In order to achieve this outcome, the history of ACE Schools in America and South Africa will be discussed, as well as the role of the school, the parent and the teacher in missio Dei. An analysis and evaluation will be done on Christian educators such as Martin Luther, John Calvin and John Knox, as well as educational deform under Hitler. A study will be done on how Biblical doctrine was formed in children’s lives in the Old and New Testament. / Thesis (M.A. (Missiology))--North-West University, Potchefstroom Campus, 2012.
140

An evaluation of the Accelerate Christian Schools for reaching children for the Kingdom of God as part of Missio Dei in South Africa / Jones D.J.C.

Jones, Dina Johanna Christina. January 2011 (has links)
Secularist views are a challenge to the field of religious education. Their worldview and influence in society will be discussed. This study evaluates the theocratic model under the apartheid regime, the co–operative model and the religion policy under the new democratic government. The areas that the researcher investigated in this study are centred on the effectiveness of the mission calling of the School of Tomorrow, Accelerated Christian Education. In order to achieve this outcome, the history of ACE Schools in America and South Africa will be discussed, as well as the role of the school, the parent and the teacher in missio Dei. An analysis and evaluation will be done on Christian educators such as Martin Luther, John Calvin and John Knox, as well as educational deform under Hitler. A study will be done on how Biblical doctrine was formed in children’s lives in the Old and New Testament. / Thesis (M.A. (Missiology))--North-West University, Potchefstroom Campus, 2012.

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