Typescript (photocopy). / Digitized by Kansas Correctional Industries / Department: Biology.

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Master of Dental Surgery / It has been considered for the purpose of this review unnecessary to discuss in detail the Morphology of the dental pulp and dentine, as this may be found in any recognised text-book, but to concentrate on the clinical problems involved. The materials discussed are those in current usage for exposed pulp preservation, whilst other materials may be touched upon and it is the endeavour of the author to review as many results as possible in this field and to draw sound conclusion from statements made. The field of corticosteroids in dentistry is comparatively new and here it is the aim to provide a basis from which further research may be undertaken. Thus, this thesis is divided into two distinct sections. The first section dealing with non-corticoid drugs and the second sections dealing with cortico-steriods and their combinations, exclusively, utilising the commercial product Ledermix as their prime example. However, when considering pulp therapy one must delve into the past to understand the thought and effort that has gone into this realm of dentistry and to note the lack of the true scientific attitude by some into this work. This may then allow us to look again at our own statements to note how much controversy there was, and still is concerning a question such as “should an attempt on the pulp once exposed ever be made to maintain its vitality?” It will be shown at a later stage that the pulp has marvellous recuperating powers if treated in a conservative manner, something which was hardly considered even early this century. Castognola, Quigleyand Berman have all reviewed this subject before. However, my aim is to bring together all of their information as a preface to the important work of considering the immediate study being carried out in this field. The first attempted vital capping was carried out by Philip Pfaff in 1756 with a small piece of gold foil adapted to the base of the cavity. Then in 1826 it was reported that Lenoard Koeker cauterized the exposed pulp with a hot iron wire and placed silver or lead caps over the exposures. It then appeared that little further was written concerning pulp capping until the middle of the 19th century when Albrecht (1856) utilised opiates, caustics and eugenol on the exposed pulp. McKown (1859) recommended cotton soaked in creosote and tannic acid, whilst Taft (1859) was in favour of cauterizing recently exposed pulps with nitric acid and placing a filling immediately. These results were purely a subjective evaluation. In fact Mc Kown’s results were produced on one of his own teeth. The history of pulp preservation really begins in the early 1860’s. Allport (1866) and Atkinson (1866-1868) suggested amputation of all projecting cornua of exposed pulps and placement of a temporary filling until it was healthy. Allport used the b lood clot formed during operation as his means of capping. J Foote (1866) also, believed the blood clot to be the best means of covering the pulp. This certainly appeared to be a reasonable assumption, considering medical knowledge of the day.

Leptin is primarily an adipose-derived hormone that acts in the hypothalamus to regulate body fat levels by suppressing appetite and increasing metabolic rate. Pregnancy is characterised by increased food intake and fat mass to meet the metabolic demands of this physiological state. Leptin concentrations also increase during pregnancy, but this does not prevent the pregnancy-induced hyperphagia, suggesting a state of leptin resistance. The aims of this thesis were to measure hypothalamic leptin responsiveness during pregnancy and to investigate the potential mechanisms underlying pregnancy-induced leptin resistance. The satiety response to intracerebroventricular (i.c.v) leptin was measured in fasted non-pregnant (diestrous), early pregnant (day 7), and mid-pregnant (day 14) rats. Serial blood samples collected from another group of rats demonstrated that despite initial elevated plasma leptin concentrations in pregnant rats, fasting significantly decreased leptin concentrations so that pregnant and non-pregnant groups had similar, low leptin concentrations. Leptin treatment significantly reduced food intake in non-pregnant and early pregnant rats but not in mid-pregnant rats. In addition, there was no post-fasting hyperphagic response in the pregnant rats. These results indicate that pregnant rats become resistant to the satiety action of leptin. To investigate the mechanisms underlying pregnancy-induced leptin resistance, leptin-induced activation of hypothalamic leptin-target neurons was examined. Signal transducer and activator of transcription 3 (STAT3) phosphorylation was measured in non- pregnant and mid-pregnant rats following i.c.v. administration of leptin. Western blot and immunohistochemistry analysis indicated that leptin-induced STAT3 phosphorylation was significantly reduced in the ventromedial nucleus of the hypothalamus (VMH) during pregnancy. A suppression in the amount of leptin-induced STAT3 activation was observed in the arcuate nucleus during pregnancy, yet there was no overall change in the number of leptin responsive neurons compared to non-pregnant rats. This raises the possibility of a decrease in the degree of responsiveness of arcuate nucleus neurons to leptin during pregnancy. Using double-labelled immuno-histochemistry for alpha-melanocyte stimulating hormone (α-MSH) and leptin-induced pSTAT3 it was demonstrated that pro-opiomelanocortin (POMC) neurons remain responsive to leptin during pregnancy. In the VMH, consistent with the reduced pSTAT3, pregnancy also induced a 2-fold reduction in mRNA for the long form of the leptin receptor (Ob-Rb), the only isoform with full signal transduction capabilities. Expression of mRNA for one of the short forms of the leptin receptor (Ob-Ra) in the choroid plexus was decreased in early and late pregnancy, suggesting that reduced leptin transport into the brain may contribute to pregnancy-induced leptin resistance. CSF/plasma leptin concentration ratios did not differ between pregnant and non-pregnant rats however, suggesting unimpaired leptin transport during pregnancy. These results indicate that pregnancy is a state of hypothalamic leptin resistance and is associated with impaired activation of the leptin-induced JAK/STAT3 signalling pathway in the VMH and arcuate nucleus, and reduced expression of Ob-Rb mRNA in the VMH. This state of leptin resistance represents an important adaptation of the maternal brain allowing increased food intake and fat mass so that the maternal body can meet the metabolic demands of pregnancy and prepare for the subsequent demands of lactation.

Includes bibliographical references (leaves 281-328) / iii, 328 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The experiments reported are investigations of the pituitary of rats stunted by undernutrition imposed between birth and 3 weeks of age. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Physiology, 1971

Includes bibliographical references (leaves 191-207) / xiv, 207 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the interactions between thyroid hormones and male reproductive function in mature, prepubertal and post pubertal Merino rams. Hypothyroidism or hyperthyroidism was induced in these rams for 8-10 weeks and their reprodroductive endocrine axis and testis functions were assessed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1986

Bibliography: leaves 161-189. / xx, 189 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of the series of experiments described in this thesis was to investigate the functional characteristics of the subpopulations of the corticotrophs in the fetal pituitary during normal development and after chronic intrauterine stress. / Thesis (Ph.D.)--University of Adelaide, School of Molecular and Biomedical Sciences, Discipline of Physiology, 2004

Includes bibliographical references (leaves 281-328) The experiments reported are investigations of the pituitary of rats stunted by undernutrition imposed between birth and 3 weeks of age.

The neurohypophysial peptide system is involved in modulating a variety of physiological, neurological, and behavioral responses in vertebrates. The principal forms of these peptides in non-mammalian tetrapods are vasotocin (VT) and mesotocin (MT). The studies described in this thesis used pharmacological, molecular, and biochemical techniques, along with phylogenetic analyses, to identify and characterize the mRNA sequences encoding the neurohypophysial peptide precursor proteins and their receptors in urodele amphibians. The cDNAs encoding preproVT and preproMT were amplified by PCR from the brains of two salamander species; the rough-skinned newt, Taricha granulosa, and the red-legged salamander, Plethodon shermani. The neurohypophysial peptides encoded by the identified Taricha cDNAs were VT and MT; the Plethodon cDNAs encoded VT and a novel MT-like peptide, [Val⁴]-MT. Phylogenetic analyses grouped both the Taricha and Plethodon preproVT and preproMT-like sequences with previously identified tetrapod preproVT-like and preproMT-like sequences, respectively. Additional analysis of the preproneurohypophysial sequences indicated that gene conversion (non-homologous crossing over of DNA sequences) appears to have occurred more frequently in mammals than in other tetrapod classes. The cDNAs encoding the VT receptor (VTR) and MT receptor (MTR) were amplified from the brain of T. granulosa by PCR. Sequence identity, and phylogenetic analysis, indicated that the Taricha MTR and VTR were most similar to MTR/OTRs and V[subscript 1a]-like VTRs, respectively. Distribution of PCR amplicons specific to the Taricha MTR and VTR matched previously reported tissue distributions of MTRs and VTRs in other vertebrates in every tissue but kidney, from which the Taricha primers were unable to amplify a cDNA product. Binding experiments of transiently expressed Taricha MTR indicated two binding states, and allowed the determination of ligand binding affinities for this receptor. Inositol phosphate accumulation assays demonstrated that the expressed Taricha MTR and VTR cDNA produced functional receptors, and allowed calculation of ligand potencies of activation and inhibition. Surprisingly, an antagonist frequently used in behavioral experiments to specifically block VTR activity, inhibited inositol phosphate accumulation in cells transfected with either the Taricha MTR or VTR. In conclusion, these studies report the first identified cDNA sequences encoding the preproVT, preproMT, MTR, and V[subscript 1a]-like VTR proteins from urodele amphibians. / Graduation date: 2005