Chau Shuk Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 103-115). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENT --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT IN ENGLISH --- p.v / ABSTRACT IN CHINESE --- p.viii / TABLE OF CONTENTS --- p.xi / Chapter CHAPTER I - --- INTRODUCTION / Chapter 1.1 --- Fluid Transport in Human Colon --- p.1 / Chapter 1.2 --- C1' Secretion across the Colonic Epithelium --- p.2 / Chapter 1.3 --- Properties of T84 Cells --- p.7 / Chapter 1.4 --- General Introduction on Extracellular Calcium Sensing Receptor (CaSR) --- p.8 / Chapter 1.5 --- Molecular Structure of CaSR --- p.9 / Chapter 1.6 --- CaSR-mediated Intracellular Signaling --- p.13 / Chapter 1.7 --- Agonists of CaSR --- p.16 / Chapter 1.8 --- Functions of CaSR --- p.18 / Chapter 1.8.1 --- Homeostatic Functions of CaSR --- p.18 / Chapter 1.8.2 --- Non-Homeostatic Functions of CaSR --- p.18 / Chapter 1.9 --- Molecular and Functional Study of CaSR Expressed in Colon --- p.19 / Chapter 1.10 --- Objectives of the Present Study --- p.21 / Chapter CHAPTER II - --- MATERIALS AND METHODS / Chapter 2.1 --- Solutions and Drugs --- p.22 / Chapter 2.2 --- Cell Culture --- p.23 / Chapter 2.3 --- Western Blot --- p.26 / Chapter 2.4 --- Simultaneous Measurement of Short-Circuit Current (Isc) and Intracellular Calcium Concentration ([Ca2+]i) --- p.27 / Chapter 2.4.1 --- Measurement of Isc and Transepithelial Resistance with Ussing Chamber --- p.27 / Chapter 2.4.2 --- Simultaneous Measurement of Isc and [Ca2+]i --- p.29 / Chapter 2.5 --- Measurement of Isc with Conventional Ussing Chamber --- p.32 / Chapter 2.6 --- Measurement of Intracellular cAMP Accumulation with Enzyme-Linked Immunosorbent Assay --- p.34 / Chapter 2.7 --- Data Analysis --- p.34 / Chapter CHAPTER III - --- RESULTS / Chapter 3.1 --- Expression of CaSR in T84 Cell Monolayers --- p.36 / Chapter 3.2 --- Poly L-arginine Induced an Increase in Isc --- p.38 / Chapter 3.2.1 --- Simultaneous Measurement of Isc and [Ca2+ ]i in Response to Poly L-arginine --- p.38 / Chapter 3.2.2 --- Interaction Between Poly L-arginine and Forskolin --- p.50 / Chapter 3.2.3 --- Ionic Mechanism of Isc Stimulated by Poly L-arginine --- p.58 / Chapter 3.2.3.1 --- Involvement of C1- in Isc Stimulated by Poly L-arginine --- p.58 / Chapter 3.2.3.2 --- Involvement of Basolateral K+ Channels in Isc Stimulated by Poly L-arginine --- p.61 / Chapter 3.2.4 --- Signaling Pathways Underlying the Isc Response to Poly L-arginine --- p.73 / Chapter CHAPTER IV - --- DISSCUSION / Chapter 4.1 --- Presence of CaSR in T84 Cell Monolayers --- p.78 / Chapter 4.2 --- Simultaneous Measurement of Isc and [Ca2+ ]i upon Application of Poly L-arginine --- p.82 / Chapter 4.3 --- Ionic Mechanism Underlying the Increase in Isc Stimulated by Poly L-arginine --- p.87 / Chapter 4.4 --- Signaling Pathway Underlying the Action of Poly L-arginine --- p.93 / Chapter 4.5 --- Does CaSR Mediate Poly L-arginine-evoked C1- Secretion across T84 Cell Monolayers? --- p.96 / Chapter 4.6 --- Future Study --- p.101 / REFERENCES --- p.103

L’obésité, le diabète de type 2 et l’athérosclérose sont les principaux problèmes de santé publique affectant les pays développés. Bien que de nombreux traitements soient disponibles contre ces maladies, de nombreux progrès sont encore nécessaire pour le développement de composés plus actif et plus sûr. Mon laboratoire a montré que l’activation du récepteur aux acides biliaires TGR5 par ses ligands entrainait une augmentation de la dépense énergétique et réduisait le niveau des cytokines chez la souris, ce qui pourrait être une nouvelle voie vers le traitement de ces désordres métaboliques. Nous décrivons ici le développement d’un nouvel agoniste synthétique, spécifique et puissant pour TGR5. A partir d’une librairie de 20.000 composés, les composés 50980906, 13008574 et 37525283 ont été caractérisés comme les plus puissants et stables. Le composé 13008574 a montré une réduction significative sur la prise de poids de souris C57BL/6J après un régime alimentaire riche en graisses. Suite à l’activation de TGR5, nous avons observés une augmentation du niveau d'expression des gènes Ucp-1, Dio-2 et Cpt-1 dans le tissu adipeux brun et une augmentation de la clairance du glucose suite à une augmentation de la sécrétion de GLP-1 chez les souris traitées par le composé 13008574. Nous avons également montrés que le composé 13008574 n’a pas d’effet sur les souris TGR5-/- témoignant de sa spécificité. Enfin nous avons par ailleurs confirmé l'effet du composé 13008574 comme agent anti-inflammatoire, avec un effet protecteur face au développement de l'athérosclérose. Notre travail montre ainsi que le développement d’agonistes pour TGR5, puissant et sûr, est possible pour traiter le syndrome métabolique. / Obesity, type 2 diabetes and atherosclerosis, are amongst the main driving factors of a public health crisis that impacts developed countries. Although several drugs are available, there is still a large unmet medical need to find better and safer compounds to treat these diseases. In this context, my host laboratory discovered that activation of the membrane bile acid receptor TGR5 induces energy expenditure and reduces inflammation in mice, which would be beneficial to manage the above–mentioned disorders. INT-777, a semi-synthetic bile acid, is until now, one of the most specific TGR5 ligands. Here, we report the identification of a new synthetic, selective and potent TGR5 agonist. From a screen of 20,000 compounds as potential TGR5 activators, the compounds 50980906, 13008574 and 37525283 were the most potent and stable. In particular, 13008574 induced a significant reduction of body weight gain when C57BL/6J mice were exposed to a high fat diet, paralleled by an increase in the expression levels of Ucp-1, Dio-2 and Cpt-1 in brown adipose tissue. In addition, mice treated with 13008574 displayed improved glucose clearance, consequent to increased GLP-1 secretion. We showed furthermore that the effects of 13008574 were lost in TGR5-/- mice, testifying the specificity of the compound. In addition, 13008574 acts as an anti-inflammatory agent, with a protective effect on atherosclerosis development in LDLr-/- mice treated with a high cholesterol diet. Our work hence shows that potent, selective, and safe TGR5 agonists can be developed to cure the metabolic syndrome.

Les cannabinoides (CBs) et plus spécifiquement les agonistes des récepteurs CB2 ontdémontré leurs propriétés analgésiques, sans effet psychotrope comparés auxagonistes CB1. Les CBs sont généralement des composés lipophiles et non “drug-like”présentant une faible biodisponibilité. Afin d’évaluer de nouveaux CB2 agonistesd’origine synthétique développés par notre laboratoire, sur des modèles in vivo dedouleur neuropathique, une stratégie de formulation précoce a été mise au point et apermis le développement de quatre systèmes de délivrance d’actif. Une étudepharmacologique d’efficacité a été conduite avec notre tête de série MDA7, formulédans des complexes d’inclusion avec des cyclodextrines (CDs), des liposomes et unesolution micellaire administrés par voie parentérale. Le concept à base de CDs adémontré une plus forte activité anti nociceptive. Une étude de compréhension dumécanisme d’inclusion de MDA7 dans le complexe supramoléculaire formé avec lesCDs a été menée. Des systèmes auto-émulsionnables (SEDDS) ont également étéutilisés pour une administration orale afin d’étudier le profile pharmacocinétique deMDA7. Des nanocapsules (NCs) polymériques et cationiques ont également été développéesafin de stabiliser un phytocannabinoide, CB2, en vue d’une administration in vivo. Desétudes pour caractériser et évaluer l’influence des paramètres affectant la formation desNCs préparées par nanoprécipitation ont été conduites. Nous avons étudié lapropension des NCs développées à former des interactions ioniques avec desmacrocycles anioniques tels que les sulfobutylether-β-cyclodextrines ou, desinteractions électrostatiques avec les cucurbit[n]urils / Cannabinoids (CBs) and particularly CB2 agonists have been shown to reduce pain andinflammation without eliciting any apparent psychotropic effect conversely to CB1agonist compounds. CBs candidates are usually lipophilic non drug-like compoundswith poor bioavailability. To serve the purpose of evaluating new synthetic CB2 agonistsdeveloped by our group, on in vivo neuropathic pain models, an enabling formulationstrategy has been set up and four Drug Delivery Systems (DDS) developed. Forparenteral administration, cyclodextrin (CD)-based inclusion complexes, liposomes andsurfactants/co-solvents micellar solution have been investigated whereas Self-Emulsifying DDS (SEDDS) was selected for oral administration. A pharmacologicalstudy conducted with lead compound MDA7, formulated in CD-based DDS resulted inthe higher antinociceptive activity. A comprehensive study of the inclusion mechanismof MDA7 in the CD supramolecular complexes prepared was carried out. MDA7pharmacokinetic profile was also generated formulated in micellar solution and SEDDS.Besides, cationic polymeric nanocapsules (NCs) have been designed to serve as aprotective DDS for oral administration of a dietary phytocannabinoid CB2 agonist.Studies were undertaken to characterize and evaluate the influence of differentparameters on NCs formation prepared by nanoprecipitation. The cationic NCsdeveloped have been explored for their property to yield proportion of counterioniccondensation in the presence of macrocycles bearing anionic groups such assulfobutylether-beta-cyclodextrin or to form electrostatic interactions/host-guestcomplexion with cucurbit[n]uril.

O melanoma é o mais agressivo tumor da pele, cuja resistência aos tratamentos quimioterápicos tem promovido a crescente utilização de imunoquimioterapia, como é o caso da utilização de agonistas dos receptores Toll-Like (TLRs). Nesse contexto, os compostos abreviados por P-MAPA e seu sintético estrutural MRB-CFI-1 com reconhecidas propriedades antitumorais e imunológicas, são fortes candidatos na terapia e prevenção desse tipo de câncer. Esse estudo visa determinar o potencial anticâncer do P-MAPA e de MRB-CFI-1 contra o melanoma murino em consequência ao padrão de resposta microambiental semelhante ao de morte imunogênica, em regimes de tratamento terapêutico ou vacinal, na vigência de quimioterapia com cisplatina e/ou em associação com antígenos de células tumorais totais. Após avaliação In vivo do crescimento de tumores B16F10 implantados em modelos murinos selvagem e nocaute para o gene Myd88, na vigência ou não do tratamento com cisplatina e/ou P-MAPA, nossos resultados mostraram que o P-MAPA apresentou atividade pró-tumoral e antagonizou a ação da cisplatina em inibir o crescimento dos tumores, de forma dependente de Myd88. Além disso, através de análises qualitativa e quantitativa pelo software ImageJ em fotomicrografias de secções tumorais coradas histologicamente, observamos que o P-MAPA promoveu mudanças microambientais nos tumores que podem impactar negativamente em seu desempenho. Como monoterapia em esquema de vacinação com lisado tumoral total em combinação com quimioterapia, o P-MAPA em dose baixa falhou em suprimir o crescimento de tumores B16F10, mas o seu sintético MRB-CFI-1 foi capaz de prevenir o crescimento desse tipo de melanoma num regime de vacinação profilática. Apesar do sucesso terapêutico desse imunomodulador em diversos modelos de câncer e de doenças infecciosas, o P-MAPA não foi eficaz em produz respostas microambientais contra o melanoma murino, dados esses que limitam a aplicabilidade clínica do composto. De outro modo, o composto fosfato inorgânico MRB-CFI-1 foi protetivo em retardar o aparecimento desse tipo de doença. Assim, o presente estudo foi importante por ampliar o entendimento funcional do P-MAPA numa abordagem imunoquimioterápica em modelos biológicos de tumores de melanoma, e representa uma importante mudança na utilização de constituintes individuais similares ao P-MAPA que sejam mais eficazes, de fácil obtenção, e de produção controlada e garantida / Melanoma is the most aggressive skin cancer, whose resistance to chemotherapeutic treatments has promoted the increasing use of immunochemotherapy, as is the case for the use of Toll-Like receptor agonists (TLRs). In this context, the compounds abbreviated by P-MAPA and its structural synthetic MRB-CFI-1 with recognized antitumor and immunological properties are strong candidates in the therapy and prevention of this type of cancer. This study aims to determine the anti-cancer potential of P-MAPA and MRB-CFI-1 against murine melanoma as a consequence of the microenvironmental response pattern similar to that of immunogenic death in therapeutic or vaccine treatment regimens when using chemotherapy with cisplatin alone or in combination with whole tumor cell antigens. After In vivo evaluation of the growth of B16F10 tumors implanted in wild-type and Myd88 gene knockout mice, under treatment or not with cisplatin and / or P-MAPA, our results showed that P-MAPA showed pro-tumor activity and antagonized the action of cisplatin in inhibiting the growth of tumors in a Myd88-dependent manner. In addition, using qualitative and quantitative analysis by ImageJ software in histological images of tumor sections, we observed that P-MAPA promoted microenvironmental changes in tumors that may negatively impact its performance. As monotherapy in vaccination schedule with total tumor lysate in combination with chemotherapy, low dose P-MAPA failed to suppress the growth of B16F10 tumors, but its synthetic MRB-CFI-1 was able to prevent the growth of this type of melanoma in prophylactic vaccination regimen. Despite the therapeutic success of this immunomodulator in various cancer models and infectious diseases, P-MAPA has not been effective in producing microenvironmental responses against murine melanoma, data that limit the clinical applicability of the compound. Otherwise, the inorganic phosphate compound MRB-CFI-1 was protective in delaying the onset of this type of disease. Thus, the present study was important because it broadened the functional understanding of P-MAPA in an immuno-chemotherapeutic approach in biological models of melanoma tumors and represents an important change in the use of individual constituents similar to P-MAPA that are more efficient, easily obtainable, and controlled and guaranteed production

A detomidina é um agonistas α2 adrenérgicos amplamente empregado para sedação, analgesia e medicação pré-anestésica em equinos. A ativação dos receptores α2 distribuídos no Sistema Nervoso Central e Periférico provoca uma série de alterações fisiológicas, tais como bradicardia, bloqueio átrio-ventricular, diminuição do débito cardíaco, bradipnéia, inibição da secreção de insulina, hiperglicemia, diminuição da motilidade gastrointestinal, relaxamento da musculatura esquelética, diminuição da secreção de ACTH e ADH, hipnose e sedação. Para investigar a interferência da detomidina sobre alguns parâmetros fisiológicos e metabólicos, seis equinos foram mantidos em estação e submetidos a uma hora de infusão contínua de detomidina na dose de 20 μg.kg-1.h-1 , servindo como seus próprios controles. Foram avaliados frequência cardíaca (FC), frequência respiratória (FR), pressão arterial média (PAM), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), tempo de preenchimento capilar (TPC), temperatura retal (TR), hemogasometria sanguínea, glicose e lactato plasmáticos, insulina sérica, proteína plasmática total (PPT), hematócrito (Ht), hemoblobina (Hb), saturação de oxigênio (SO2), bicarbonato, sódio, potássio, e cálcio ionizado sanguíneos, glicogênio e lactato muscular e realizada urinálise, antes da infusão contínua de detomidina (T0), 20 minutos após (T20), 40 minutos após (T40) e 60 minutos após (T60), quando a infusão foi descontinuada. Uma hora após o término da infusão, foi realizada uma última coleta (T120). As variáveis foram submetidas à ANOVA, teste t de Student, teste de Tukey e teste de Friedman de acordo com o tipo de variável com nível de confiança de 95%. Os resultados indicaram diminuição estatisticamente significativa da FC, FR, Ht, Hb, cálcio ionizado e glicogênio muscular, além de aumento significativo da glicose, lactato e bicarbonato sanguíneos. Não houve diferença estatística significativa nas variáveis TPC, TR, PAM, PAS, PAD, PaO2, PaCO2, pH arterial, SO2, insulina sérica, PPT, lactato muscular e variáveis urinárias. A utilização de uma infusão contínua de detomidina na dose preconizada neste estudo promoveu um período de sedação prolongada em equinos em estação, com ocorrência de efeitos adversos moderados e sem significância clínica em animais hígidos. A hipoinsulinemia provocada por esta droga de fato influencia o metabolismo energético através da mobilização de reservas observada e do aumento de lactato sérico. / The detomidine is an α2 adrenergic agonist widely used for sedation, analgesia and premedication in horses. The activation of α2 receptors distributed in Central and Peripheral Nervous System causes a series of changes, such as bradycardia, atrioventricular block, decreased cardiac output, bradypnea, inhibition of insulin secretion, hyperglycemia, decreased gastrointestinal motility, relaxation of skeletal muscle, decreased secretion of ACTH and ADH, hypnosis and sedation. To investigate the interference of detomidine on some physiological and metabolic parameters, six horses were subjected to one hour of continuous rate infusion of detomidine at a dose of 20 μg.kg-1.h-1 and served as their own controls. We assessed heart rate (FC), respiratory rate (FR), mean arterial pressure (PAM), systolic blood pressure (PAS), diastolic blood pressure (PAD), capillary refill time (TPC), rectal temperature (TR), blood gases, blood glucose, plasma lactate, serum insulin, total plasma protein (PPT), hematocrit (Ht), hemoblobin (Hb), oxygen saturation (SO2), bicarbonate, sodium, potassium, ionized calcium, muscle glycogen and muscle lactate, and urinalysis performed before the infusion of detomidine (T0), after 20 minutes (T20), 40 minutes after (T40) and 60 minutes after (T60), when the infusion was discontinued. One hour after the infusion was performed a last collection (T120). The variables were submitted to ANOVA, Student's t test, Tukey’s test and Friedman’s test according to the type of variable with a confidence level of 95%. The continuous rate infusion of detomidine resulted in a significant decrease in FC, FR, Ht, Hb, ionized calcium and muscle glycogen, and a significant increase in glucose, plasma lactate and bicarbonate. There was no statistically significant difference in the variables TPC, TR, PAM, PAS, PAD, blood gases, serum insulin, PPT, muscle lactate and urinary variables. The use of a continuous rate infusion of detomidina in the recommended dose in this study promoted a prolonged sedation, with moderate adverse effects with no clinical significance in healthy animals. The hypoinsulinemia caused by this drug did influence energetic metabolism through the mobilization of reserves and the observed increase in plasma lactate.

Abstract not available

Der Einsatz von Ketamin erfolgt in der Humananästhesie, vor allem aufgrund seiner vielfältigen Nebenwirkungen, nur noch nach strenger Indikation. In der Veterinärmedizin ist Ketamin tierartenübergreifend für die Injektionsnarkose weit verbreitet. Um den bekannten Nebenwirkungen vorzubeugen, wird Ketamin mit verschiedenen anderen Anästhetika kombiniert und stellt so ein sicheres Narkoseverfahren bei Tieren dar. Eine besondere Herausforderung ist die Anästhesie bei ophthalmologischen Patienten unter Berücksich-tigung der Kontrolle des Intraokularen Drucks (IOP). In diesem Zusammenhang gibt es in der Literatur widersprüchliche Angaben zur Auswirkung von Ketamin auf den IOP beim Menschen und verschiedenen Tierarten. Auch für die Auswirkungen von Propofol und der endotrachealen Intubation auf den IOP existieren widersprüchliche Aussagen. In der vorliegenden Arbeit wurde untersucht, ob gängige Ketamin-Kombinationsnarkosen bei der augengesunden Katze einen Einfluss auf den IOP haben. Angeregt durch Berichte in der Literatur wurde zudem untersucht, ob die Applikation von Propofol sowie die endotracheale Intubation den IOP bei der Katze beeinflussen. Methodik: Untersucht wurden 48 adulte, augengesunde Katzen, die dem chirurgischen Patientengut der Klinik für Kleintiere der Universität Leipzig entstammten. Es handelt sich um eine prospektive, randomisierte Blindstudie. Die Patienten wurden vier Untersuchungsgruppen zugeordnet. Zur intramuskulären Narkoseeinleitung erhielten Tiere der KX-Gruppe Ketamin (10 mg/kg) und Xylazin (1 mg/kg), der KXAtr-Gruppe Ketamin (10 mg/kg), Xylazin (1 mg/kg) und Atropin (0,025 mg/kg), der KA-Gruppe Ketamin (20 mg/kg) und Acepromazin (0,5 mg/kg) und der KM-Gruppe Ketamin (10 mg/kg) und Medetomidin (50 g/kg). Bei allen Patienten wurde mittels Tono-Pen® XL zu verschiedenen Zeitpunkten der IOP bestimmt: vor Narkoseeinleitung (Ausgangswert), nach Narkoseeinleitung nach 5, Zusammenfassung 86 10, 15 und 20 Minuten und direkt nach der Intubation sowie final nach Beendigung der Narkose während der Aufwachphase. Einige Tiere erhielten zur Vertiefung der Narkose vor der Intubation Propofol. Im Anschluss erfolgte eine ophthalmologische Untersuchung der Patienten, um eine Augenerkrankung auszuschließen. Ergebnisse: Der mittlere Ausgangs-IOP aller Tiere beträgt 15,8 mmHg. Mit p = 0,756 besteht kein signifikanter Unterschied zwischen den Gruppen. Getrennt nach linken (OS) und rechten (OD) Augen ist der mittlere IOP 15,7 und 15,8 mmHg. Dieser Unterschied ist nicht signifikant (p = 0,442). Daher wird für die Auswertung der Mittelwert aller 6 Datenpunkte pro Tier und Messzeitpunkt zugrunde gelegt. Im Vergleich zum Ausgangswert zeigt die KX-Gruppe keine signifikanten IOP-Änderungen. Die KXAtr-Gruppe und die KM-Gruppe weisen zur Final-Messung einen signifikanten IOP-Abfall um 16 % (p = 0,012) bzw. 17 % (p = 0,021) im Vergleich zum Ausgangswert auf. Die KA-Gruppe zeigt zur 15-Minuten-Messung den stärksten IOP-Abfall mit 21 % Prozent (p = 0,001) gegenüber dem Ausgangswert. Ab der 10-Minuten-Messung bis zur post-Intubations-Messung ist der IOP-Abfall der KA-Gruppe signifikant. Für die Gesamtstichprobe hat die Intubation keinen signifikanten Einfluss auf den IOP (p = 0,063). Die Gabe von Propofol zur Vertiefung der Narkose bei einzelnen Tieren hat ebenfalls keinen signifikanten Einfluss auf den IOP (p = 0,42). Schlussfolgerung: Die verwendeten Ketamin-basierten Narkoseprotokolle bewirken bei der augengesunden Katze keinen signifikanten IOP-Anstieg. Die Gruppen KX, KXAtr und KM gewährleisten für den Zeitraum von 20 Minuten nach Narkoseeinleitung einen relativ stabilen IOP. Trotz des signifikanten IOP-Abfalls in der KA-Gruppe sind sämtliche IOP-Schwankungen aller Gruppen klinisch nicht relevant. Die gemessenen IOP-Werte bewegen sich alle im physiologischen Bereich. Zudem geben die Ergebnisse keinen Hinweis auf eine IOP-Steigerung infolge Propofolgabe und Intubation bei der Katze. / Ketamine is used in human medicine based on strict indications, mainly due to its numerous side effects. In veterinary medicine however Ketamine is commonly used to induce anesthesia intramuscularly throughout all species. To minimize the well known side effects Ketamine is used in combination with several other anesthetics and thus represents a safe anesthetic procedure in animals. Ophthalmological patients are a particular challenge for anesthetists with regard to maintaining the intraocular pressure (IOP). Conflicting data can be found in the literature about the effects of Ketamine on IOP in humans and various animal species. The literature also contains various statements about the effects of Propofol and endotracheal intubation on IOP. In this clinical trial we investigated the effects of commonly used Ketamine-based anesthetic protocols on IOP in cats. Motivated by conflicting statements in the literature the analysis of the effects of Propofol and endotracheal intubation on IOP was included in the study. Methods: This is a prospective, randomized, blinded study. 48 adult cats without ophthalmological abnormalities, recruited from the pool of admitted surgical patients of the Department of Small Animal Medicine of the University of Leipzig were included in the study. The patients were assigned to one of the following four groups and anesthesia was induced intramuscularly. Cats in the KX-group were induced with Ketamine (10 mg/kg) and Xylazine (1 mg/kg). Cats in the KXAtr-group were induced with Ketamine (10 mg/kg), Xylazine (1 mg/kg) and Atropine (0,025 mg/kg). Cats in the KA-group were induced with Ketamine (20 mg/kg) and Acepromazine (0,5 mg/kg). Cats in the KM-group were induced with Ketamine (10 mg/kg) and Medetomidine (50 g/kg). In all patients the IOP was measured three times per eye using the Tono-Pen® XL at particular times: baseline IOP before induction of anesthesia, at 5, 10, 15 and 20 minutes after induction of anesthesia, after intubation and final IOP after completion of surgery. Some cats received a single bolus of Propofol to be able to tolerate endotracheal intubation. After the final IOP-measurement all Zusammenfassung 88 cats were subjected to an ophthalmological examination, including slitlamp biomicroscopy and gonioscopy, in order to exclude patients with ophthalmological pathologies. Results: The mean baseline IOP for all animals is 15,8 mmHg (SD 4,0). There is no significant difference between the four groups (p = 0,756). The mean IOP for the right (OD) and left eyes (OS) of all patients was 15,8 mmHg and 15,7 mmHg, respectively. There is no significant difference between right (OD) and left eyes (OS) (p = 0,442). Therefore all further analyses are based on the mean of all six data points per animal and measuring time. The KX-group shows no significant IOP-change relative to baseline-IOP. The KXAtr and KM-group show a significant decrease in IOP of 16 % and 17 %, respectively, at the final measurement compared with baseline-IOP. The KA-group shows a significant decrease in IOP starting at 10 minutes after induction of anesthesia until the post-intubation measurement. The maximum decrease in IOP in this group is 21 % relative to baseline-IOP 15 minutes after induction of anesthesia. For the total data no significant influence of endotracheal intubation on IOP could be detected (p = 0,063). The application of Propofol in a total of 14 cats has no significant effect on IOP (p = 0,42). Conclusion: The Ketamine-based anesthetic protocols used in this study do not cause a significant increase in IOP in cats without ophthalmological abnormalities. The KX, KXAtr and KM-group ensure a relatively stable IOP for the time period of 20 minutes after induction of anesthesia. Despite the significant IOP-decrease in the KA-group none of the IOP-changes in all groups examined are of clinical relevance. All of the collected IOP-values are within the physiological range for cats. There is no evidence for an increase in IOP caused by endotracheal intubation or the application of Propofol.

No description available.

The role of Indian hedgehog (Ihh) signalling in the regulation of endochondral bone formation is well established. Ihh controls the rate of bone growth by negatively regulating differentiation and positively regulating growth plate chondrocyte proliferation. It has been well documented also that mutations resulting in constitutive activation of signalling through FGFR3 in chondrodysplasia, lead to a significant decrease in this important signalling factor accompanied by reduced proliferation of the chondrocytes and a dwarf phenotype. / In an attempt to rescue the chondrodysplasia phenotype hedgehog agonist Hh-Ag 1.4 was injected subcutaneously into mice with achondroplasia (ACH) or with severe achondroplasia with developmental delay and acanthosis negricans (SADDAN) with mixed results. / Administration of a hedgehog agonist in SADDAN mice led to a significant up-regulation of both Ptch and Gli1, as measured by quantitative PCR, indicating that Hh-Ag 1.4 does indeed stimulate hedgehog signalling in vivo. Also, in situ hybridization for Ihh seems to show a down regulation of native Ihh expression in pre-hypertrophic chondrocytes, possibly due to the activation of the negative PTHrP feedback loop. In our study, Hh-Ag 1.4 treatment resulted in an increased growth plate length and reduced size of the hypertrophic zone. The cortical bone flanking the growth plate in mice injected with Hh-Ag 1.4 was 2-3 times thicker than in control mice, which may be attributed to the positive effect of increased Ihh signalling in osteoblastogenesis. Contrary to our expectations, there was also a noticeable reduction in chondrocyte proliferation in mice treated with the agonist. / Overall, the effect on the growth of long bones was not beneficial and the treatment with high doses of Hh-Ag 1.4 did not result in an amelioration of the chondrodysplastic phenotype.

The extended striatum is a large, dopamine-innervated forebrain structure comprising the caudate-putamen, nucleus accumbens and olfactory tubercle (OT). The OT remains largely unexplored, despite its potentially important role in behaviour and dopamine (DA)-mediated reward. One method of studying function is examining "supersensitive" behavioural responses to DA agonists in animals after striatal DA loss. We examined whether D1 or D2 receptor supersensitivity occurs in the OT and neighbouring islands of Calleja (ICj), after unilateral 6-hydroxydopamine lesions of the medial forebrain bundle and medial OT (mOT). We also asked if the resulting DA receptor supersensitivity is anatomically heterogeneous. Our results showed D1-like receptor supersensitivity occurring in the OT with several DA agonists, and heterogeneously across the extended striatum. There is evidence of D2-like receptor supersensitivity in the ICj. Our focal mOT lesion failed to show DA receptor supersensitivity. Finally, there is little evidence for D2 supersensitivity as measured by [ 35S]GTPgammaS binding.