The differentiation of preadipocytes into adipocytes is one of the most intensely studied biological processes and has led to the understanding of a number of signaling pathways involved in cell growth and differentiation. The nuclear phosphatidyl inositol (pl) signalling pathway, centred around the enzyme phospholipase C (PLC) βI has been demonstrated to be involved in a number of cellular processes such as mitogenesis and differentiation. Recently components of another lipid signalling pathway, that involving prostaglandins, have also been shown to localise at or within the nucleus. To date, there have been no reports demonstrating the role of either of these nuclear pathways during the differentiation of adipocytes. The 3T3-L1 preadipocyte cell line was used to study the role of nuclear pI and prostaglandin lipid signalling in adipocyte differentiation. In Chapter 3 data is presented to show that two phases of nuclear PLC βl activity occur during adipocyte differentiation. The first phase occurs within minutes of differentiation being induced, is regulated by the actions of extracellular signal-related kinase (ERK) l/2 and protein kinase c (pKC) α, and is involved in the mitotic clonal expansion phase of differentiation. The second phase of activity occurs from day 2 of differentiation, is regulated independently of ERK 1/2 and pKC α and is involved in the regulation of the cell cycle factors cyclin D3 and cyclin-dependent kinase (cdk) 4. In Chapter 4 I investigate the nuclear localisation of prostaglandin synthases, how their localisation is altered by differentiation, and the role of these enzymes in adipocyte differentiation is characterized through inhibitor studies. Cytosolic phospholipase A2 (cPLA2) cyclooxygenase (COX) 1 and 2, microsomal prostaglandin E2 synthase (mPGES), prostacyclin synthase (PGIS), lipocalin prostaglandin D2 synthase (L-PGDS) are localised to the nuclear membrane and their localisation changes during differentiation. The COX 1 and2 enzymes also localise within the nucleus and this COX 1 localisation appears to be cell cycle dependent. COX 2 is functionally coupled to mPGES and PGIS and plays a role in adipocyte differentiation as inhibition of COX 2 with a specific inhibitor (NS 398) completely blocks adipocyte differentiation. COX 1 is functionally coupled with L-PGDS and appears to be involved in lipid metabolism as the inhibition of COX 1 with a specific inhinitor (SC 560) partially blocks lipogenesis. In Chapter 5, I investigate the localisation of prostaglandin receptors in the differentiation process. 3T3- L1 cells express the prostaglandin E2 (EP4) receptor, prostaglandin F2α (FP) receptor and the prostaglandin D2 (DP) receptor but these do not have a nuclear localisation. Activation of the DP receptor is involved in lipid metabolism as the DP receptor antagonist, BW A868C, partially inhibits lipogenesis. lnternalisation of prostaglandins appears to be necessary for differentiation to occur fully as treatment of differentiating 3T3-L1 preadipocytes with the anionic transport inhibitor bromocresol green (BCG) partially inhibits carbaprostacyclin (cPGI2) induced differentiation and completely inhibits that caused by cyclopentenone prostaglandins. Thus, nuclear lipid signalling pathways appear to play a role in the process of adipocyte differentiation and a proper understanding of these pathways may lead to a better understanding of fat cell development and the role it plays in obesity and its related diseases. / Whole document restricted, but available by request, use the feedback form to request access.

Measurement of diastolic left ventricular (LV) function is vitally important in the assessment of cardiac disease. However, only limited information on tissue function can be obtained with current clinical techniques. This Thesis developed and investigated novel parameters of both global and regional myocardial function, using cardiac magnetic resonance imaging (MRI) with three-dimensional tissue tagging. Multidirectional peak myocardial shortening strains and strain rates, as well as the peak systolic displacement and velocity of the mitral valve annulus plane (MVP), were considered as parameters of LV systolic function. The corresponding peak diastolic strain relaxation rates and peak diastolic MVP velocity were used to assess diastolic function. The effects of normal ageing were studied in people with no evidence of cardiac disease, and compared with the effects of disease in patients with type 2 diabetes mellitus (DM). In normal healthy subjects, systolic strain parameters were preserved, while diastolic parameters were impaired, with age. DM patients showed impaired diastolic function on correction for age, and systolic functional parameters were also impaired, even though LV ejection fraction was normal. MVP systolic and diastolic motion were reduced both with age and in DM patients. Systolic LV torsion was increased with age and in DM, with no corresponding increase in torsional relaxation. Both systolic and diastolic function parameters were regionally heterogeneous. With normal ageing, diastolic function was impaired in a regionally non-uniform manner. Thus, a complete assessment of LV function requires measurement of LV tissue mechanics as well as chamber haemodynamics. MRI provides valuable information regarding myocardial tissue behaviour, contributing to systolic and/or diastolic dysfunction, which cannot be obtained otherwise. Systolic tissue dysfunction may develop concomitantly in patients with diastolic dysfunction, even when global ejection fraction is preserved. Regional analyses provide important information on how local changes contribute to global function. The influence of age must be taken into account in studies of disease.

Voltage-activated Ca2+ channels and group I metabotropic glutamate receptors (mGluRs) are important determinants of neuronal excitability and repetitive discharge behaviour. They are also implicated in perinatal developmental processes and Ca2+ -dependent excitotoxic cascades thought to contribute to neurodegeneration. To understand the role that these channels/receptor systems play in the physiology, ontogeny and pathophysiology of MNs, it is necessary to characterise them, during development, in MNs that differ functionally in the behaviours they control, the firing behaviour they produce, their rate of maturation, and their vulnerability to degeneration in ALS. Surprisingly few studies, however, have characterised these channels/receptor systems in MNs, particularly beyond early postnatal stages. I therefore compared voltage-activated Ca2+ channels and group I mGluRs in brain slices from neonate (P1-5) and juvenile (P14-19) rat, in oculomotor (III) and hypoglossal (XII) MNs using whole-cell patch-clamp recording and immunohistochemical techniques. III MNs innervate extraocular muscles, control eye movements that are not fully functional in rat until 2 weeks postnatal, fire at high frequency for sustained periods, and are resistant in ALS. In contrast, XII MNs innervate tongue muscles, control behaviours that are functional at birth, fire bursts of low frequency action potentials, and are vulnerable to degeneration in ALS. In neonates, low voltage-activated (LVA) Ca2+ current densities are similar in III and XII MNs but high voltage-activated (HVA) Ca2+ current densities are ~2-fold higher in XII MNs. While N- and P/Q-type HVA Ca2+ channels are present in both MN pools, greater expression of P/Q-type channels in XII MNs accounts for their greater HVA Ca2+ currents. Developmentally, LVA and HVA Ca2+ current densities decrease ~2-fold by P14-19 in III MNs, but remain unchanged in XII MNs. Thus, in juveniles the HVA Ca2+ current density is ~3-fold greater and the LVA ca2+ current density ~2-fold greater in XII compared to III MNs. The group I mGluR agonist, DHPG, induces inward currents in III and XII MNs of neonatal and juvenile rat, which are mediated by the reduction of a resting K+ conductance. Antagonism of these currents by the mGluR1 antagonist LY367385, but not the mGluR5 antagonist MPEP, and immunohistochemical labelling for mGluR1a but not mGluR5 protein on III and XII MNs, suggest that currents primarily result from the activation of mGluR1. In neonatal rat the current density of DHPG-induced currents is similar between III and XII MNs. However, in juvenile rat DHPG-induced current density is ~3-fold greater in XII compared with III MNs. Differential expression of LVA and HVA Ca2+ currents and varying effects of group I mGluR activation in III and XII MNs during development supports a role for these channels and receptor systems in determining the distinct firing patterns of these two different classes of MNs. The greater voltage-activated Ca2+ currents and group I mGluR-mediated effects in XII MNs, particularly in juvenile MNs, may also contribute to the greater sensitivity of XII MNs to pathophysiological processes, predisposing them to degeneration as seen in ALS.

No description available.

Breastfeeding benefits the mother as well as the baby. Breast milk is a complete food for newborn human infants, adequately supplying all nutritional needs for at least the first 4- 6 months of life (Kramer & Kakuma, 2002). In 1993, the Commonwealth of Australia recommended the following goals for promoting breastfeeding by the year 2000 and beyond (Nutbeam, Wise, Bauman, Harris & Leader, 1993): For infants to the age of three months, 60% should be fully breastfed or 80% should be partially breastfed. For infants to the age of six months, 50% should be fully breastfed or 80% should be partially breastfed. However, according to the most recent national survey, these targets have not been met (Donath, 2000). In effect, breastfeeding figures have not changed in the last ten to fifteen years (Mortensen, 2001). Research indicates that the largest decrease in breastfeeding occurs between two weeks and six weeks after birth (Binns & Scotts, 2002; Stamp & Crowther, 1995; Mogan 1986), with women giving Insufficient Milk Supply (IMS) as the major reason for stopping. Despite research in the field of physiology, biochemistry, psychology and socioeconomics, this phenomenon of IMS remains an 'enigma' (Hill, 1991, p. 312). However, failure to thrive in infancy can be seen in babies who do not achieve an adequate weight gain within the normal time span. According to lactation consultants at the Royal Women’s Hospital Breastfeeding Assessment Service in Melbourne, some babies who are breastfed present with inadequate weight gain due to IMS. Women with low breastmilk supply who wish to persist with breastfeeding often look for some means to increase their milk supply. There are very few alternative treatment to assist them. For over a thousand years mothers in China have used acupuncture to increase their supply of breast milk. Within the last decade, several authors have published results of studies on the effect of Traditional Chinese Acupuncture (TCA) on lactation (Wu, 2002; Huang & Huang, 1994; Tureanu, 1994; Dong, 1988; Kang, 1990). These study all indicated improvement in lactation after TCA therapy. However, all these studies have been uncontrolled clinical trials. This research is a first single blind controlled clinical trial to investigate the effectiveness of Traditional Chinese Acupuncture for the treatment of IMS. The aim of the study is to find out whether a course of Traditional Chinese Acupuncture treatment would help mothers diagnosed with insufficient breast milk supply produce more milk. This clinical trial was conducted by a qualified Traditional Chinese Medicine practitioner. The researcher gained a Bachelor of Medicine degree in TCM after completing the five years program at the Beijing College of TCM in China. The researcher has been in clinical practice for more than 15 years. This is a pilot study. The final number of subjects in the study was 27,: 9 in the Traditional Chinese Acupuncture (TCA) Group; 6 in the Sham Acupuncture (SA) Group and 12 in the Non-Treatment Control Group. The major finding of the study was that - 'Other things being equal, infants whose mothers received TCA weighed 160.13 grams more on average than those whose mothers received SA. This effect is marginally significant (p less than 0.1)'. The finding generally confirms that the Traditional Chinese Acupuncture intervention to the mother is effective in increasing infant weight gain.

Psychogenic symptoms (trouble sleeping, lack of energy, difficulty in concentration, nervous tension, feelings of sadness/ downheartedness) are among the most frequently reported symptoms of menopausal transition, as are nocturnal hot flushes/sweats. Few studies have combined psychosocial and biomedical models to seek an explanation as to why menopausal symptoms such as these are problematic for some but not all women during menopausal transitional. In Study 1, 71 transitional women (mean age: 50.02 years, SD: 3.52 years) completed questionnaires examining the predictive value of a number of psychosocial factors in terms of the impact of menopausal symptoms on the ability to maintain a normal lifestyle during transition. Participants included women undergoing natural transition and those using hormone replacement therapy (HRT). A sub-set of participants (N=22) with the highest and lowest psychogenic symptom frequency scores took part in Study 2. Their evening on-set salivary melatonin secretion levels were compared, as was their exposure to natural light at 500, 3,000 and 10,000 lux levels, their subjective and objective (wrist actigraph) sleep quality and their nocturnal peripheral body temperatures (PBT). Results from Study 1 indicated that, while the quality and availability of health care was of most concern to all participants, domestic environment, including quality of relationships and communications, was the main predictor of successful transition when assessed as the ability to maintain a normal lifestyle during transition. No significant differences were found between natural or HRTassisted transition in terms of the impact of symptom severity, or the predictive value of psychosocial factors. Participants with low psychogenic frequency scores (less frequent symptoms) showed a trend towards higher evening on-set melatonin secretion levels, and had significantly greater exposure to natural light than their high psychogenic frequency counterparts. These results were consistent regardless of transitional status (natural or HRT-assisted). No significant differences between the high and low psychogenic symptom groups were found in either subjective or objective sleep quality. However, women with high psychogenic frequencies spent significantly more hours with higher peripheral body temperatures (35º - 36ºC) and reported significantly more nocturnal hot flush/sweat episodes than their low psychogenic frequency counterparts. These results show that, in terms of overall menopausal transition, domestic environment plays a major role in the way in which transitional women are able to deal with the impact of menopausal symptoms during transition. They also suggest a permissive link between melatonin evening on-set of rhythms and psychogenic symptoms that may be mediated by exposure to natural light. However, these results should not be viewed in isolation from each other, but in combination with each other. It could be argued that a healthy domestic environment may affect the perception of symptom severity. This could result in greater involvement in domestic and social activities outside the home, increasing exposure to natural light, and thus better entrained melatonin secretion on-set rhythms. However, any inference of causation (rather than association) requires experimental verification, preferably in research designs where key factors, such as exposure to natural light, can be experimentally manipulated.

Most research on the mental life of medical patients has focused on personality characteristics said to influence the experience and reporting of physical symptoms. This is despite minimal support for personality as causally related to physical illness. The popularity of daydreaming (and dreaming) is widespread in the self-help market. Yet research definitions of mental life have seldom included imaginal activities. The aim of this research was to establish a health (and mental life) profile of patients in general practice to the west of Melbourne. The principal focus was to determine if the health of patients could be predicted by mental life. Two studies were conducted. The first study investigated mental life in the form of daydreaming. Patients, approached prior to their consultation with a general practitioner, completed the Short Form Health Survey (SF-36), Severity of Physical Symptoms Checklist (SPSC), Daydream Frequency Scale (DFS), and Short Imaginal Processes Inventory (SIPI). The mental health of the sample was below the norm in the general population. The physical health of males, but not females, was also below the norm. Most patients reported less frequent daydreaming. They did, nevertheless, report more negative daydreams (than the norm). Patients unable to maintain sufficient mental control reported more negative daydreams, but not more (or fewer) positive daydreams. More negative daydreams predicted lower mental health. Patients reported fewer positive daydreams than the norm, and more positive daydreams did not improve their mental health. These findings were only partially consistent with the research literature. The second study sought to explore these findings further by determining if they were mediated by life orientation. Patients completed the Revised Life Orientation Scale (LOT-R), in addition to the SF-36 and SIPI. There were important sex differences in relationships between measures of mental life and mental health. For females, more pessimism was related to more negative daydreams and predicted lower mental health. For males, insufficient mental control predicted lower mental health. Consistent with the first study, positive daydreams (and optimism in the second study) was not related to male or female mental health. Results for females support recent research indicating that it is pessimism, and not optimism, that is the principal determinant of mental health. It is clear, however, that much more research on the correlates of male mental health, and how these differ from those of females, is warranted. The findings of the present research suggest that daydreaming is not a mundane activity: rather it is an important dimension of mental life requiring further consideration in mental health research.

The research work described in this thesis has two studies on processes that may lead to adipic acid production through hexanoic acid synthesis pathway by the anaerobic bacterium Megasphaera elsdenii and its subsequent utilisation by Pseudomonas strains. The first part of the research described was concerned with the ability of Pseudomonas putida (syn P. oleovorans) to convert hexanoic acid to adipic acid. However, despite a sustained effort the research was unable to confirm the formation of adipic acid in these strains and this line of research was not pursued further. The research however, did show for the first time that these Pseudomonas strains could produce octanoic acid from n-octanol vapours in the presence and absence of n-hexanoic acid and has thus led to important new information. The second line of research pursued and which constituted the major research effort was concerned with an investigation on regulation and production of the metabolic intermediates and end-products during glucose and lactate metabolism in M. elsdenii. A number of wild type strains were studied as well as mutants isolated as resistant to 3-fluoropyruvate were used to investigate end-product inhibition and the biochemical pathways used for fermentation. Small volume cultures and controlled fermenters were used to investigate the fatty acid end-products during glucose, lactate and mixed substrates and to optimise the effect of pH on growth and metabolism. An important finding was that the mutant ME5 produced relatively more valeric and hexanoic acid compared to its parental strain ATCC 25940 in mixed substrates. While in the presence of glucose, the proportion of valeric acid produced by strain ME5 was higher than seen for its parental strain ATCC 25940 and mutant ME7. Another important finding was that pH control improved the yield of acids compared with uncontrolled fermentation. The work described in this thesis was also concerned with the recovery of fermentation products to obtain higher productivity and more efficient recovery of the products by adsorption to anion exchange resins. Initially, Amberlite IRA-93 (weak base anion-exchange resin) and Amberlite IRA-400 (strong base anion-exchange resin) resins were tested for their ability to adsorb and desorb butyric and hexanoic acids from water and peptone-yeast-glucose media. It was observed that both resins adsorbed more n-hexanoic acid than n-butyric acid, which suggested that the VFA chain length might affect the degree of adsorption. Both acids were desorbed more effectively by esterification from Amberlite IRA-93 resin. This indicated that Amberlite IRA-93 might have some attractive features above Amberlite IRA-400 in terms of product recovery in the form of esters. Further studies were carried out on the adsorption and desorption of both acids on the fermentation level in peptone-yeastglucose media under pH controlled and uncontrolled pH conditions. Results indicated that using the Amberlite IRA-93 had an advantage in that it did not release a counter ion on binding of anions so that it exerts a buffering effect on the fermentation broth, thus reducing the degree of pH control needed and the amount of alkali used to maintain the optimum pH. The outcome of this finding is that better yields and better recovery of products can be achieved. Another line of research was concerned with the key enzymes involved in the fermentation and the genes coding for them. The research detected pyruvate dehydrogenase (PDH) in strain ATCC 25940 for the first time and showed that the activity of this enzyme was significantly lower in the mutant ME5. However, lactate dehydrogenase (LDH) activity in ME5 was significantly higher compared with ME7 and the parent ATCC 25940. It was also shown that enzyme expression was highest in exponential growth. It was concluded that the relative changes in PDH and LDH in ME5 were responsible for the changes in carbon flow to acid end-products. The final component of the research was concerned with a preliminary investigation of the molecular biology of the enzymes leading to the formation of hexanoic acid. The sequence of the short-chain acyl-CoA dehydrogenase (SCAD) in ATCC 25940 and mutants ME5 and ME7 were obtained and compared. However, no changes were seen which could explain the altered end-products. Likewise a minor change in the sequence of the electron-transferring flavoprotein was unlikely to affect the metabolic activity. An attempt to design PCR primers from related sequences of lactate dehydrogenase to investigate the LDH genes was unsuccessful.

Narcolepsy is a debilitating sleep disorder, characterized by excessive daytime sleepiness, cataplexy, hypnogogic hallucinations, sleep paralysis and automatic behaviour. Automatic behaviour can be defined as 'stereotyped and repetitive sequences of actions that are performed without awareness', which usually occur during monotonous tasks (Zorick, Salis, Roth, & Kramer, 1979, p. 194). A classic example is reaching a destination without realizing how one got there. At present little is known about this complex phenomenon, and research in the area is minimal. The aim of the current study was to document the phenomenon of automatic behaviour in ten individuals with narcolepsy (selected on the basis of self-report of moderate to severe automatic behaviour), via phenomenological analysis and a series of case studies. Data was obtained through two structured interviews with each participant, an interview with a spouse or family member, a weekly journal and a daily journal (completed on minimal medication). Using qualitative methodology, a number of important features of automatic behaviour were identified. The current study provided an in depth analysis of the loss of recall associated with episodes of automatic behaviour and was able to define the types of errors associated with this state (sequencing errors, item/ environment intrusions, perseverative action leading to nonsense, context inappropriate behaviours). Different types of automatic behaviour were identified. Type 1 (sleepiness with low cognitive load) and Type 2 (sleepiness with high cognitive load) have been previously reported in the literature (but not so labeled). Type 3 (high cognitive load without sleepiness) however has not previously been identified. The vigilance levels associated with these types (from microsleeps to fluctuating vigilance levels) were discussed, making comparisons with previous research in the area (Guilleminault et al, 1975; Valley, & Broughton, 1981; 1983). Subsequently, a hypothesised formula for automatic behaviour was developed, including the various factors in its manifestation (that is, excessive daytime sleepiness, cognitive load, and individually determined threshold for automatic behaviour). A descriptive model of automatic behaviour was also developed and compared to previous research. An explanation from a cognitive perspective was considered, linking the automatic behaviour experienced in narcolepsy to automatic behaviour in normals. Finally, a questionnaire to measure automatic behaviour was developed, for further research to pilot.

The experiences of working in an acute psychiatric unit were investigated in this research using multiple qualitative methodologies, particularly Reflective Topical Autobiography and Participatory Action Research. The Participatory Action Research was undertaken in an acute psychiatric unit of a major public hospital in Melbourne. The collaborative design focused on bringing staff and consumers of psychiatric services together with an aim to develop new work practices for mental health practitioners. Four consumer consultants including a Koori representative participated in this study. Consumer consultants and staff, working in collaboration with the researcher, informed the fluid and iterative research process. Data included thirty eight interviews with psychiatric health professionals (2 psychiatrists, 2 managers, 6 psychiatric registrars and 28 nurses, including two charge nurses). Horizontal violence, and its impact on the capacity for reflexive work practices, became a strong emergent theme. Other emergent and important themes included workplace hierarchy, values, power, and the impact of critical incidents and supervision. Ego-state theory was utilised to better understand the psychology of staff members, and Organisational Egostate theory was presented as an original concept to explore the psychiatric unit as an organism having its own personality characteristics. It was concluded that for there to be permanent and iterative change to the organisation that engrained automatic responses of the organisation need to be identified and new responses developed. The research resulted in a number of new work practice recommendations, including the establishment of non-discriminatory review processes where work practices that are viewed as inappropriate by staff and consumers can be assessed with consideration to the importance of all stakeholders. Specific insights and conclusions have been suggested in relation to the treatment of aboriginal (Koori) people in the psychiatric unit. A central conclusion from this study was that psychiatric staff and consumers need more inclusion in the design and review of work practices.