Over the past decade, a number of epidemiological studies have provided significant evidence that certain major adult noncommunicable diseases, such as hypertension, ischaemic heart disease and non-insulin dependent diabetes mellitus, may be associated with impaired fetal growth. This phenomenon has been termed "programming" which is essentially the term used for persisting changes in structure and function caused by undernutrition or other adverse influences acting during critical periods of early development. Programming has been used as the mechanistic basis to explain the long term sequelae of intrauterine growth retardation (IUGR). The mechanisms underlying the epidemiological observations remain to be elucidated and developed. While it is well established that severe maternal undernutrition during pregnancy leads to IUGR, there has been relatively little well defined animal studies of the somatotrophic axis and postnatal development of growth retarded offspring. The major objectives of this thesis were to establish a model in the rat of IUGR by nutritional restriction of the dam throughout gestation and to examine the effects of fetal growth retardation on endocrine, molecular and growth parameters during postnatal development. In addition, the development of an animal model for IUGR enabled well defined studies testing distinct hypotheses suggested by the epidemiological observations of professor David Barker and colleagues. Timed matings were performed in Wistar rats and dams were randomly assigned to one of two dietary treatment groups. A control group was fed ad libitum throughout pregnancy and a restricted group was fed 30% of ad libitum intake. Restricted fed dams were observed to lose a significant amount of body weight throughout gestation, due to undernutrition, but caught up to the ad libitum group during the lactating period. Maternal undernutrition significantly reduced fetal and placental weights without altering litter size. Postnatally, body weights of offspring from undernourished dams continued to be reduced until at least 18 weeks of age, although they were observed to be growing at the same rate as ad libitum offspring by 2 weeks of age. A cohort of animals from undernourished dams were maintained to measure blood pressure by tail cuff plethysmography. Offspring from undernourished dams were found to have significantly elevated systolic blood pressures from 18 weeks of age. This observation provides direct experimental support for the hypothesis, derived from human epidemiological studies, that the origin of adult hypertension may originate during fetal life as a result of exposure to a sub-optimal intrauterine environment. Parallel reductions in plasma IGF-I and hepatic IGF-I mRNA concentrations before 15 days of age were also observed in growth retarded offspring. Hepatic IGF-I transcription start sites within exon 1 and exon 2 were coordinately reduced with IUGR up to 15 days of age without changes in GHR and GHBP mRNA abundance. The lack of catch-up growth observed in the IUGR offspring despite normalization of their plasma IGF-I and IGF-I mRNA levels from 15 days of age may be due to a state of partial resistance to GH. This observation lead to a series of treatment studies in which neonatal and juvenile offspring from ad libitum and undernourished dams were treated with growth factors to investigate somatic growth responses as a measure for hormone sensitivity. In both treatment studies, ad libitum offspring from both age groups and juvenile IUGR offspring responded to GH treatment However, neonatal IUGR offspring did not exhibit any response to GH treatment.. Analysis of IGF-I gene expression in neonatal offspring showed that GH treatment elevated IGF-I Eb mRNA in ad libitum but not IUGR offspring. These results suggest a possible mechanism for transient GH resistance in that a post-receptor defect in GH action may contribute to the development of temporary postnatal GH resistance as a consequence of IUGR and fetal programming of IGF-I gene expression. In summary, the development of a model of IUGR in the rat using maternal undernutrition throughout gestation has enabled detailed investigation of nutritional regulation of the somatotrophic axis during fetal development and postnatal sequelae. The studies in this thesis have shown that the somatotrophic axis is markedly altered postnatally by nutritional restriction of the dam throughout gestation, leading to prolonged postnatal growth retardation and elevated blood pressure The mechanisms which lead to the induction of such fetal programming and whether these changes may contribute to the development of subsequent adult-onset disease remain to be addressed in future studies.

This thesis is based on two theoretical models of chronic illness: Large, Butler, James, and Peters (1990) introduced a systems model of musculo-skeletal pain which incorporated many of the variables believed to be important in the development and maintenance of pain. Feldman’s model (1974) addressed the difficulties of adapting to chronic illness. Five studies evaluated specific aspects of these models. The epidemiology of pain in New Zealand (NZ) was derived from a psychiatric epidemiology project. Approximately 80% of NZ adults had experienced a life disrupting episode of pain which had required medical consultation. Subjects who reported episodes of pain were more likely to have psychiatric diagnoses of anxiety, depression, and phobia. They were more likely to describe their health as poor and were currently consulting their doctor more than people who did not report an experience of pain. The estimated average cost of health consulting by people attending Auckland Hospital Pain Clinic (AHPC) for the previous year was $1333(NZ). Most people had some subsidy of costs. The health consulting of the AHPC group was higher than that reported in the NZ health literature. Self image and the experience of pain were assessed in two studies. The first asked subjects at AHPC to describe the typical thoughts, feelings, and behaviours, of someone with chronic pain. Subjects described loss of self esteem, alienation from family and friends, fear of the future, frustration and anger. The descriptions focused on psychological aspects of the experience of pain. The second study of self image used repertory grid technique. Two standardised Illness Self Construct Repertory Grids (ISCRG) were evaluated. Issues in the use of standardised grids are discussed and some aspects of ISCRG application are explored. The two ISCRG indicated subjects often identified themselves as a physically ill person and felt isolated from others. People with pain and their "closest other” (CO) completed the ISCRG(A) and questionnaires on the quality of their relationship. Closest others overestimated the role of the physical illness in their partners’ life and believed that they understood them better than the individual with pain thought they did. The personality dimensions of alexithymia and hypnotisability have been hypothesised as pathways for the development of psychosomatic illness. Individuals with chronic pain were tested to establish whether they weremore alexithymic and more hypnotisable than subjects in a general population control group. This was not verified. The constructs of alexithymia and hypnotisability require critical examination. The experience of pain is common and is associated with psychological distress and high health service use. Self construct appears to be a major factor determining response to pain and to treatment programmes. Chronic pain appears to be a particular challenge for individuals who must accept alteration in their lifestyle with perhaps little understanding of what the future may hold. / Whole document restricted, but available by request, use the feedback form to request access.

This poststructuralist qualitative study explored the discourses constructing women’s choice for a caesarean section in the absence of clinical indications, in the talk and texts of women, midwives, an obstetrician, professional journals and the media publications. The study affirms inscriptions surrounding choice in childbirth are shaped discursively through a multiplicity of discourses underpinned by social and institutional practices. With advances in technology, childbearing women have a greater variety of options from which to choose. Controversial, is the option of a caesarean section, regardless of clinical need. The issue is depicted in both professional and popular discourse as contentious, complex and contradictory. Its momentum into the 21st century, as a new object of obstetric discourse, has been played out on a number of platforms. In this thesis I draw from the theoretical ideas of French philosopher Michel Foucault, to examine this complex debate. I argue there is a volatile moment in the history of childbirth in which an explosion of discourses have sculptured choice for a caesarean, in the absence of clinical indications, out of a repartee of autonomy, convenience, desire, fear and risk. In this precarious moment, new meanings joust with the old on a shifting terrain awash with rhetoric that co-opts, competes, and contradicts to bring about a caché of mutable ‘truths’. Whether caesarean, as an optional extra, can be explained in terms of a libertarian imperative, an embodiment of lifestyle, the satiation of desire, the attenuation of fear or the avoidance of risk, the democratisation of this choice has exposed a pathologising paradox, whereupon the normal emerges as the abnormal, and the abnormal emerges as the normal. The deconstruction of choice through a poststructuralist lens has enabled insight into how contradiction and contest befall the ‘order of things ’ and in so doing, provides new openings for contemplating the discursive positioning of women through the competing discourses of childbirth.

The developmental origins of health and disease hypothesis suggests that exposure to adverse prenatal environmental influences can determine an individual’s susceptibility to obesity in adult life. However, the specific causal mechanisms which underlie this hypothesis have yet to be identified. Focusing on the potential mechanistic role of the leptin endocrine axis, the main objective of this thesis was to investigate the long term effects of prenatal undernutrition and different levels of postnatal nutrition on leptin sensitivity and the development of diet-induced obesity (DIO) in the Wistar rat. A well established animal model of maternal undernutrition during pregnancy was used to induce prenatal undernutrition in experimental offspring. To investigate the interaction between prenatal nutrition and postnatal diet, and its effects on obesity development, female offspring were placed on three different diets: standard chow, a high fat diet or a calorie restricted diet. The effects of prenatal undernutrition and postnatal diet on leptin sensitivity were investigated, in adult offspring, by measuring the response to 14 days of peripheral leptin treatment. Changes in gene expression in the liver, retroperitoneal adipose tissue and soleus muscle were then characterised by custom microarray and quantitative real-time RT-PCR (QPCR) analysis. Adult female offspring exposed to prenatal undernutrition (UN offspring) were found to exhibit leptin resistance in adulthood, independent of postnatal DIO. This result demonstrates for the first time that exposure to prenatal undernutrition has a long term effect on adult leptin sensitivity. In UN offspring fed on a high-fat diet, leptin resistance significantly accelerated the development of DIO while in contrast, offspring maintained on calorie restriction remained lean. These findings suggest that prenatal nutrition can shape future susceptibility to DIO by altering postnatal leptin sensitivity. An analysis of gene expression suggests that prenatal undernutrition causes the development of peripheral tissue-specific leptin resistance, and may also further enhance an offspring’s susceptibility to DIO by altering the regulation of peripheral tissue lipogenesis, mitochondrial function, glucocorticoid metabolism and insulin sensitivity. In conclusion, these studies identify peripheral leptin resistance as a key mechanism that can influence postnatal susceptibility to DIO in female offspring exposed to prenatal undernutrition. Furthermore, the identification of specific changes in peripheral gene expression highlights four additional metabolic mechanisms which may also facilitate the development of DIO in leptin resistant UN offspring.

In the first trimester of human pregnancy specialised placental cells, termed cytotrophoblasts differentiate into extravillous trophoblasts (EVTs), which grow out from the placenta and invade into the maternal decidua, acting to physically attach the placenta to the decidua, and adapt the uterine spiral arteries to support pregnancy. A proportion of these EVTs also temporarily occlude the spiral arteries for approximately the first 10 weeks of gestation, preventing maternal blood flow to the placenta and creating a low oxygen environment in which placental and fetal development occur. The processes of trophoblast outgrowth and invasion, and the establishment of a low oxygen environment, are essential for the success of pregnancy, and inadequate trophoblast invasion into the uterus has been associated with recurrent miscarriage, pre-eclampsia and fetal growth restriction. However, the exact mechanisms that control the differentiation of cytotrophoblasts down the extravillous trophoblast lineage are poorly understood. Since the extent of this invasive process is unique to human implantation, animal models are of limited value in studying trophoblast invasion. Existing in vitro models have major limitations in that many are very difficult to quantify while others many not study the correct trophoblast population. The research in this thesis has focussed on the development of novel models by which to study cytotrophoblast differentiation, and the use of these models to further understand cytotrophoblast differentiation down the EVT lineage, and the regulation of EVT outgrowth by oxygen. Methods Outgrowth from first trimester villous explants was characterized using immunohistochemistry. Explant viability was investigated using dual staining with chloromethylfluorescin diacetate (CMFDA) and ethidium bromide, by examining DNA laddering, and by immunostaining sectioned explants over 96 hours of culture. The extended viability of cytotrophoblasts in multilayered cell islands in villous tips was exploited to isolate these cells using sequential trypsin digests of cultured villous explants. The trophoblast population obtained were characterized by immunohistochemistry. Finally, villous explants were cultured in either 1.5% or 8% oxygen and the frequency and area of outgrowths was quantified in order to determine the effect of gestation and oxygen on EVT outgrowth. Results Approximately 1/4 of explants cultured in 20% oxygen produced EVT outgrowth. Outgrowth formation and expansion resulted from proliferation of cells in the tips of anchoring villi, and EVTs within the outgrowth did not proliferate. The percentage of explants producing outgrowth declined as gestation increased from 8 to 12 weeks. Dual staining with CMFDA and ethidium bromide revealed degeneration of the syncytiotrophoblast by non-apoptotic mechanisms within 4 hours of culture, but this syncytiotrophoblast layer was able to be regenerated. The majority of cytotrophoblasts died within one week of culture, but despite this explants were able to produce EVT outgrowth for up to 3 weeks due to the extended survival of a specific set of cytotrophoblasts located in cell islands in the tips of anchoring villi. These surviving cells were able to differentiate into EVTs, but not regenerate the surrounding syncytiotrophoblast in the villus tip. Trypsinization of first trimester villi after extended explant culture resulted in the isolation of a viable population of ‘putative EVT progenitors’ that did not syncytialise in culture, but were able to proliferate. 20% of these cells differentiated down the EVT lineage within 96 hours of culture. The putative EVT progenitors expressed markers previously localised to cytotrophoblasts in cell islands of anchoring villi, including αvβ6 integrin and FGFR-2. The addition of exogenous FGF-4 did not affect the differentiation of these cells into EVTs, nor did FGF-4 alter the frequency of EVT outgrowth from explants. Culture in 1.5% oxygen significantly reduced the frequency and area of outgrowths in comparison to 8% oxygen. HLA-G and α1 integrin were both expressed throughout outgrowths with no difference in expression of these proteins between oxygen concentrations. Gestation influenced the response of explants to oxygen, with a significant differential response to oxygen concentration in placentae under 11 weeks of gestation but no differential response in placentae of 11 or 12 weeks. Conclusions In the first trimester, oxygen and gestational age regulate extravillous trophoblast outgrowth in both an independent and interdependent manner. The cytotrophoblast population in the first trimester does not consist of one homogenous bipotent population. Rather there are at least two separate populations: 1) EVT progenitors that exist in the tips of potential anchoring villi that are likely to be committed to EVT differentiation and 2) monolayer villous cytotrophoblasts which are likely to be committed to syncytiotrophoblast differentiation. The second population is easily isolated by traditional enzymatic digestion methods whereas the first much smaller population can be isolated by exploiting their prolonged survival in explant culture.

Human mammary tissue was incubated in vitro with [7-3H] dehydroepiandrosterone sulphate (DHA-sulphate) and in agreement with other investigators this steroid conjugate was metabolized to DHA and other steroid products. Sulphatase activity was greater in the malignant than the non-malignant tissues and was found to be a function of the tissue cellularity. One of the major products, a "polar steroid" necessitated identification. The "polar steroid" was identified principally as 7a-hydroxy DHA by chemical modification techniques and co-crystallization of the purified steroid metabolite with carrier 7a-hydroxy DHA. This carrier required synthesis and characterization.

Transplacental glucose transport is vital to fetal growth. Although the presence of glucose transporter-1 (GLUT1) and GLUT3 has been demonstrated in mammalian placenta, the factors regulating these genes remain unclear. Therefore, the overall aim of these studies was to clone ovine GLUT1 (oGLUT1) and oGLUT3 cDNAs, and to use these to investigate gene expression during ovine placental development and function. Ovine GLUT1 (~2.2 kb) and oGLUT3 (483 bp) cDNAs were isolated and cloned. Sequence analysis demonstrated that oGLUT1 showed high homology (97 - 99%) with other mammalian species, whereas oGLUT3 did not (84 - 88%). Northern analysis demonstrated that oGLUT1 mRNA abundance increased from d 45 to d 120 of gestation, then decreased towards term (d 145 ± 2), whereas oGLUT3 mRNA abundance increased throughout gestation. Western analysis showed oGLUT1 protein levels increased during late gestation, indicating post-transcriptional regulation of oGLUT1. Localisation experiments revealed spatio-temporal differences in ovine placental GLUT expression. In early gestation (d 45), oGLUT1 protein was restricted to fetal trophoblast cells. By mid gestation oGLUT1 immuno-signal was predominantly localised to maternal villous and endometrial tissue. By late gestation oGLUT1 mRNA was most strongly localised to maternal syncytiotrophoblast and villous tissue, whereas oGLUT3 was predominantly localised to fetal trophoblast cells. Placental oGLUT expression was regulated differently by acute (3 - 8 h) versus long-term (>6 d) alterations in late gestation maternal glucose supply. No evidence was found for regulation of placental oGLUT gene expression by long-term maternal undernutrition, but oGLUT1 and oGLUT3 mRNA and oGLUT1 protein were elevated by short-term (24 - 48 h) maternal hypoglycemia. Acute maternal hyperglycemia transiently increased oGLUT1 and oGLUT3 mRNA abundance, whereas oGLUT1 protein (but not mRNA) levels increased after long-term maternal hyperglycemia. Infusion studies provided no conclusive evidence for regulation of placental oGLUTs by long-term administration of growth hormone (GH) or insulin-like growth factor-1 (IGF-1) to the late gestation fetus. Following acute (4 h) fetal IGF-1 infusion, placental oGLUT3 mRNA abundance was greater in growth restricted (placental embolisation) than in normal fetuses, although the reason for this difference remained equivocal. This thesis describes isolation, cloning and sequence analysis of oGLUT1 and oGLUT3 cDNAs. These studies confirmed the presence of GLUTI and GLUT3 mRNA in ovine placenta, and demonstrated ontogenetic and nutritional regulation of placental oGLUT1 and oGLUT3. In addition, these results indicated that regulation of placental oGLUTs may occur at both transcriptional and post-transcriptional levels.

Whole document restricted, see Access Instructions file below for details of how to access the print copy. / Zinc is an important trace metal in human biology. It plays an active role in enzymic reactions, or simply serves in a structural capacity on a number of cytoplasmic and nuclear proteins. Zinc modulates receptor responses to various excitatory and inhibitory neurotransmitters. It has biphasic effects on several enzymes critical for cell survival and the induction of apoptotic cell death. At a particular concentration threshold, it is cytotoxic both in vitro and in vivo. Recent studies have indicated that zinc may be involved in several neuropathological conditions such as Alzheimer's disease, epilepsy, traumatic head injury and cerebral stroke. This investigation focused on the role of zinc in the context of an Alzheimer's disease paradigm. Rat primary cortical neurons were exposed to freshly-prepared (non-aged) or aggregated (aged) Aβ1-42 protein (20 µM; a highly toxic Aβ species), in the presence or absence of equimolar concentrations of zinc chloride (ZnCl2), or copper chloride (CuCl2).Zinc significantly attenuated, while copper potentiated the neurotoxic effects of non-aged Aβ1-42 after 48 h chronic exposure. Similarly, zinc, but not copper, reduced neuronal death 48 h following exposure to the aged peptide. A metal chelator, DTPA, also showed a protective, but limited effect (only observable at 24 h post-treatment) against the neurotoxicity of aged peptide. At the concentration tested, zinc alone had no effect on neuronal survival, although copper was found to be slightly neurotoxic after 48 h incubation. As hydrogen peroxide (H2O2) production by Aβ has been reported to mediate its cytotoxicity, an in vitro test system was used to identify if zinc affected this process. It was found that co-incubation of zinc (10 µM) with Aβ1-42 peptide alone (10 µM) or with Aβ1-42 and copper (1 µM) showed a significant decrease of Aβ-mediated H2O2 formation using TCEP assay in vitro. This finding suggested that the neuroprotective effect of zinc may not only be due to its capacity to hinder Aβ's redox activity, but also zinc's ability to preclude Aβ-mediated H2O2 generation. A mechanism for these effects of zinc is yet to be determined. As oxidative/nitrosative stress has been widely reported to occur in AD brain, and since zinc metabolism is believed to be dysfunctional in AD brain, the current study also set out to elucidate if cerebral zinc metabolism may be affected by nitrosating agents in vivo. Three unrelated nitric oxide-generating compounds were administered into rat hippocampus. Using Timm's and TSQ stain, a histochemical and a fluorescent staining for zinc, respectively, it was observed that sodium nitroprusside (≥2 nmol) and spermine-nitric oxide complex (≤200 nmol), but not the peroxynitrite-producing agent 3-morpholinosydnonimine (≤200 nmol), caused perikaryal zinc accumulation among certain neurons in the hippocampus. Both membrane impermeable and permeable metal chelators, EDTA and TPEN, respectively, blocked perikaryal zinc staining of hippocampal neurons. Data obtained from EDTA treatment suggested that the source of perikaryal zinc staining was mostly extracellular. Previous reports have shown that metal chelating agents have the capacity to protect neurons and minimize damage from brain insults. The preceding studies showed that chelators minimized perikaryal zinc acccumulation, precluded Aβ's redox activity, and partly reduced Aβ neurotoxicity. Thus, to further assess the possible beneficial effect of these compounds, DTPA, BP, or BC (25 µM) was incubated with a mixture of Aβ1-42 (2 µM) and Aβ1-40 (20 µM). DTPA abolished, while BP delayed the Aβ1-42-mediated Aβ1-40 "seeding" process. This result suggested that contaminating trace metals have an obligatory role in the nucleation-dependent Aβ fibrillogenesis, which is believed to be linked to Aβ neurotoxicity, and AD neuropathology. These results imply that zinc has a biphasic role in AD etiology and disease progression, and that the use of metal chelators to buffer pathologically excessive zinc and other metals, particularly the redox active copper and iron, may have a potential therapeutic value against AD symptomatology.

Whole document restricted, see Access Instructions file below for details of how to access the print copy. / Fetal growth and development is primarily limited by maternal substrate supply. Recent studies also suggest that IGFs and their binding proteins have a significant influence on fetal growth, and that maternal nutritional status is a major factor in the regulation of the IGF/IGFBP axis in fetal plasma. The aim of these studies was a) to develop specific homologous radioimmunoassays (RIAs) for ovine IGFBP-2 and IGFBP-3 for subsequent studies, b) to further define the interactions between maternal nutritional status and circulating IGFs and the IGFBPs in the sheep fetus and c) to characterise aspects of the fetal IGF/IGFBP axis that are temporarily or permanently altered (reprogrammed) in response to limited substrate supply. Such changes might provide mechanistic explanations for epidemiological data linking impaired growth in utero with increased susceptibility to specific diseases in adulthood. IGFBP-2 and IGFBP-3 were isolated from fetal and postnatal sheep serum respectively following 1) cation exchange chromatography to remove endogenous ligand, 2) IGF-2 affinity chromatography and 3) C8 and C18 reverse phase chromatography. N-terminal amino acid sequence analysis revealed strong homology for each peptide with data from several other species. Ovine IGFBP-2 had a 3 amino acid deletion at the N-terminal when compared to human or bovine IGFBP-2, the significance of which is unknown. Specific antisera were raised against both peptides and homologous RIAs were generated. While IGFs did not interfere in either RIA, IGF-1 addition was required in the oIGFBP-3 RIA to overcome a potency difference for the antiserum between purified oIGFBP-3 and plasma IGFBP-3:IGF-1 complex. Both RIAs were validated for analysis of fetal and postnatal sheep plasma. We characterised the roles of insulin and glucose in mediating the effects of substrate supply on plasma IGFs and IGFBPs in the fetal sheep. Pregnant ewes were starved for 72 hours and refed for 48 hours. Fetuses were infused with either glucose or insulin during the final 24hours of maternal starvation. Glucose, insulin, IGF-1 and IGF-2 were reduced by maternal starvation. While glucose infusion increased these parameters to near control values, insulin infusion was only associated with elevations in insulin and IGF-1 concentrations. These data suggest that insulin regulates the fetal plasma levels of IGF-1 but that IGF-2 concentrations were regulated by glucose in an insulin-independent fashion. Fetal plasma IGFBP-1 and -2 were increased, and IGFBP-3, IGFBP-4 and the circulating IGF-2/mannose-6-phosphate receptor (IGF-2/M6PR) were decreased, by maternal starvation. IGFBP-1 and IGFBP-4 levels were restored to normal by glucose and insulin infusions while the IGF-2/M6PR was increased by glucose infusion only (not measured in insulin-infused fetuses). These results are consistent with data regarding firstly the insulin dependency of IGFBP-1 and its role as a glucose counter-regulatory peptide, and secondly the role of insulin in determining IGFBP-4 and IGF-2/M6PR distribution between plasma and tissues. Fetal plasma IGFBP-2 and -3 levels were unaffected by either infusion suggesting that they are regulated by factors other than acute changes in plasma glucose or insulin. We have subsequently examined the hypothesis that exposure to undernutrition around the time of conception would result in a reduced growth rate and reprogramming of the plasma IGF/IGFBP axis in the late gestation fetus. Pregnant ewes were either well fed or undernourished from 60 days prior to mating to d30 of gestation and then subjected to a second period of undernutrition between d105 and d115 of gestation. Periconceptual undernutrition was associated in the late gestation fetus with reduced growth rate and a reduction in the circulating concentrations of IGFBP-1 and IGFBP-3. Furthermore the response of plasma IGF-1, IGFBP-1 and IGFBP-3 in fetuses of the periconceptual undernutrition group to severe maternal undernutrition in late gestation was significantly greater than that measured in fetuses from mothers well fed at the time of conception. The hypothesis that a severe nutritional insult only during late gestation would alter the postnatal regulation of plasma IGF-1 and IGFBP-3 in the lamb was also addressed. While birth weight was reduced in fetuses of mothers undernourished for 20 days, no differential effects of undernutrition in utero on the pre-pubertal ontogeny of IGF-1 and IGFBP-3 or on their response to a GH bolus could be found between the treatment groups. In summary, these studies indicate that IGFs and IGFBPs play an important role in mediating the effects of fetal substrate supply on fetal growth. Reprogramming of the responses by the plasma IGF/IGFBP axis to undernutrition in the late gestation sheep fetus could be induced by a period of periconceptual undernutrition. However, the lack of reprogramming effects on IGF-1 and IGFBP-3 in postnatal plasma following a severe nutritional insult only in late gestation suggests either that reprogramming of the IGF/IGFBP axis is dependent on exposure to undernutrition at earlier timepoints in gestation or that reprogramming of the fetal IGF/IGFBP axis does not persist postnatally.

The nexus or linkages between loneliness, stigma, health complaints, and primary medical care in older New Zealanders was explored from a social constructionist perspective. The intent of the studies was the support and explanation of the underlying arguments of the thesis. For this age group loneliness is a clinical condition which merits greater recognition, diagnosis, and treatment from general practitioners than it presently receives. As a society we silence and stigmatise loneliness in our senior citizens making it likely that they will present indirectly to their doctors when experiencing severe effects of the condition. This behaviour will increase their risk of inappropriate medical intervention at possible cost to themselves and to society. A cross sectional, randomly selected survey of 300 New Zealanders over 60 years old, aimed to establish the patterns of loneliness in the sample using quantitative analysis. The second qualitative study used the methodology of discourse analysis to identify the themes concerning loneliness and medical care in the accounts of older adults, and how these were used. Fourteen people, deemed by their doctors to be lonely and to need frequent medical care, were interviewed in order to further knowledge of the dynamics of loneliness and the medical encounter. Fifteen percent of the sample of 300 had moderate to severe loneliness scores. The sociodemographic indicators of loneliness were extremely easy for a practitioner to recognize. Less than 2% of the total of self reported doctor visits were explicitly for loneliness. According to Barsky's (1981) model, the most likely pathways to the doctor were through symptom amplification and lowered self ratings of health, with a less likely pathway through focusing on and worrying about symptoms, leading to perceived need for medical care. The predictive variances in regressions of loneliness on all health outcomes, except for self reported visiting of more than one doctor for symptoms, were lower for chronic than for situational loneliness. The most important conclusions from the second study were the identification of three rhetorical strategies or "etcetera clauses" which provided a social prescription for the indirect presentation of loneliness by older people. Loneliness may be discussed with the doctor; if it affects your physical health; if you are consulting for another reason; and if the doctor picks it up. Also, the individual doctor defines loneliness as a worthy, or non-worthy, condition for consultation.