Alcohol consumption during pregnancy can result in fetal alcohol spectrum disorders (FASD), which encompass a range of physical, behavioral, learning, emotional and social disturbances. Many mechanisms for this array of alcohol-derived fetal injuries have been proposed, but none fully accounts for the deficiencies observed. Alcohol is a ubiquitous drug that may affect the brain at any or all stages of development and at multiple sites; regional differences in vulnerability of different brain structures during different periods of exposure have been demonstrated. This study investigates possible mechanisms for the alcohol induced neurodevelopment damage seen as a result of prenatal alcohol exposure, and also includes evaluation of a potential intervention strategy (glutamine). These experiments all utilized the sheep model, which has distinct advantages over the rodent model for third trimester-equivalent studies (a time of increased vulnerability to the effects of alcohol). The fetal hippocampal formation (pyramidal cells in the CA1 and CA2/3 fields and granule cells of the dentate gyrus) and olfactory bulb (mitral cells) have been altered in response to alcohol exposure in rodent model studies. This study examined the effects on the fetal hippocampal formation and olfactory bulb in response to all three trimester-equivalent alcohol exposure in the sheep model, a species in which the third trimester-equivalent occurs in utero (as opposed to post-natal as occurs in the rodent). It is known that both maternal and fetal cortisol levels increase in response to alcohol. The role of cortisol in mediating fetal cerebellar Purkinje cell loss (known to occur with alcohol exposure) was analyzed. Lastly, the availability of circulating amino acids, both maternal and fetal, in response to alcohol are reported. The results of administration of a single acute dose of glutamine to the ewe, concurrent with alcohol, was evaluated for its ability to prevent the amino acid and pH perturbations known to occur in response to alcohol.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 165-168). Also available online.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2001. / Includes bibliographical references.

Transcription elongation regulator 1 (TCERG1) has previously been demonstrated to be an inhibitor of the transactivation and growth arrest activities of CCAAT/Enhancer binding protein alpha (C/EBPα). Furthermore, TCERG1 had been demonstrated to become relocalized from nuclear speckles to the pericentromeric regions where C/EBPα resides when both proteins are co-expressed in the cell. This thesis demonstrates that the deletion of a unique, imperfect series of 38 glutamine-alanine (QA) repeats near the amino terminus of TCERG1 is able to abrogate the ability of TCERG1 to inhibit C/EBPα-mediated growth arrest, the physical interaction between TCERG1 and C/EBPα, and the relocalization of TCERG1 from nuclear speckles when C/EBPα is co-expressed in the cell. The deletion of the QA domain demonstrated that there was a threshold amount of QA repeats required in TCERG1 for the relocalization and growth arrest inhibitory activities between TCERG1 and C/EBPα. It was demonstrated that between 11 and 20 QA repeats were required in TCERG1 to produce the relocalization from nuclear speckles or to be able to inhibit C/EBPα-mediated growth arrest. The physical interaction of TCERG1 and C/EBPα as examined by co-immunoprecipitation was also found to be QA dependent, with a diminishing interaction observed as the number of QA repeats in TCERG1 were reduced. However, experiments examining the isolated QA domain indicated that it was insufficient to relocalize an mCherry fluorescent protein fusion to either the nucleus or to pericentromeric regions where C/EBPα is concentrated. This inability to produce relocalization suggests that the QA domain requires another domain or domains from TCERG1 to mediate the relocalization activity. When expressed with the WT TCERG1, ΔQA TCERG1 was able to act in a dominant negative manner, preventing the relocalization of the WT TCERG1 protein to pericentromeric domains. Interestingly, the transactivation inhibitory activities of TCERG1 on C/EBPα do not appear to require the QA domain, but rather are localized to the carboxy half of TCERG1, somewhere within amino acids 612-1098. The data obtained provides the first report of a role for this unique QA repeat domain.

Solute carriers (SLCs) comprise the largest group of transporters in humans and there are currently 52 SLC families. They are embedded in cellular membranes and transport numerous molecules; defects in many of the genes encoding SLCs have been connected to pathological conditions, and several SLCs are potential drug targets. The SLC38 family has in total eleven members in humans and they encode transporters called SNATs. In paper I and paper II, we reported molecular and functional characterization of Slc38a7 and Slc38a8, two of the previous orphan members in the family which we suggested to be named SNAT7 and SNAT8, respectively. Using in situ hybridization and immunohistochemistry, these transporters showed similar expression pattern and localized to neurons in the brain For functional characterization proteins were overexpressed in X. laevis oocytes and an Uptake Assay and electrophysiological recordings showed preferred transport of L-glutamine, L-histidine, L-alanine, L-asparagine, L-aspartate and L-arginine for SNAT7. A similar pattern was seen for SNAT8 in a slightly different order of affinities. We classified SNAT7 as a system N transporter and SNAT8 as belonging to system A, and suggests that SNAT7 and SNAT8 could play a role in the glutamine/glutamate(GABA) cycle (GGC) in the brain. Furthermore, we studied the vesicular B0AT3 (Slc6a17) transporter in paper III, and the sodium-coupled amino acid transporter B0AT2 (Slc6a15) in paper IV. Tissue expression studies showed similar localization of Slc6a17 and Slc6a15 mRNA using in situ hybridization and real-time PCR. In paper III, vesicular localization of B0AT2 was shown in both excitatory and inhibitory neurons. When challenging the monoaminergic system with drugs both Slc6a17 and Slc6a15 were upregulated. Suggested roles for the transporters are thereby in synaptic remodeling by regulating the availability of free amino acids used as precursors needed in neurotransmitter synthesis. Moreover, in paper IV, immunohistochemistry showed B0AT3 localization to neurons, astrocytes and epithelial cells of the choroid plexus. Leucine injections caused a smaller reduction of food intake as well as higher neuronal activation in the paraventricular hypothalamic nucleus in Slc6a15 KO mice, compared with wild type mice. This suggests B0AT2 involvement in the anorexigenic effects of leucine.

Our objective was to study the effect of GLN supplementation on whole body protein turnover, somatic growth and gastrointestinal tolerance to enteral feeding in neonates following surgical stress. We hypothesized that GLN in total parenteral nutrition (TPN) would (1) favor retention of lean body mass by reducing protein breakdown (PB) during the acute phase after surgery, (2) promote somatic growth, (3) decrease length of time to achieve full feeds. Protein turnover was measured in a double-blind randomized trial involving neonates admitted to the Neonatal Intensive Care Unit after major surgery. L-GLN (n = 6) was added to TPN at a dose of 200 mg/g of protein intake. Controls (n = 7) were isonitrogenous. Isotope studies were performed on Day 4 of TPN. Subjects were given a 4-hour primed constant intravenous infusion of L-[1-13C]-leucine and [15N2]-urea. In the GLN group, a 15% reduction in PB was measured (unpaired t-test, p < 0.05). There was a trend towards improved net protein balance which was statistically different from zero in the GLN group. There were no differences in somatic growth during TPN course and in the length of time to achieve full enteral feeds. Results suggest that early TPN supplemented with GLN has a beneficial sparing effect on protein metabolism in critically ill neonates after major surgical stress.

Thesis (M.Sc.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Psychiatry. Title from pdf file main screen (viewed on October 31, 2009). Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 165-168). Also available in print.

Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: See full text for abstract / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming

Magnetic resonance spectroscopy (MRS) allows the non-invasive measurement of selected biological compounds in vivo. Despite MRS proven potential it is not yet a routine clinical tool operated by clinicians. This is mainly due to the complex procedure of MRS acquisition, lack of standardisation in both acquisition and analysis protocols along with lack of a standard quality control. This thesis intended to address these issues with the focus on four metabolites glutathione, glutamate, glutamine and GABA using MEGA-PRESS pulse sequence. Recommendations on acquisition and spectra analysis is made for the MRS protocol MEGA-PRESS aiming to detect glutathione in vivo. This is based on an investigation of glutathione acquisition in vivo and in vitro and was aimed to answer the question: can glutathione be measured reliably using conventional pulse sequence PRESS or does it require editing? The results showed strong evidence of using editing in order to have a reliable glutathione concentration measurement. An analysis along with a quality control method is also presented to enable the extraction of glutamate and glutamine from a GABA-optimised MEGA-PRESS pulse sequence. This enables simultaneous measurements of GABA, glutamate and glutamine in a single acquisition. A criterion of NAA linewidth < 8 Hz and Glx CRLB < 16% were defined as optimum features in the GABA-edited spectrum for a reliable glutamate and glutamine quantification. Finally, due to the increasing interest in functional MRS of GABA using MEGAPRESS an investigation on the feasibility of measuring GABA in a functional-MRS setting was performed with recommendations on study designs and subject size. Power calculations suggest that detecting a 40% change in GABA using a 4'30" acquisition requires 9-93 subjects per group in a between-group study design and 13- 68 participants in a within-session design, depending on the region of interest. This thesis is set out in the Journal format thesis. Three introductory chapters, with each experimental study presented as a chapter and a final chapter that summarizes and discusses the work. Results in this thesis provide a basis for a standard and reliable MRS pipeline to reliably measure glutathione, glutamate, glutamine and GABA using MEGA-PRESS pulse sequence at 3 Tesla.