Call number: LD2668 .T4 1958 P35

The work on Spiraea in vitro shoot cultures was done to determine the feasibility of using light quality to modify endogenous phytohormone balances to decrease apical dominance. Such an effect would enable a reduction in the high levels of exogenous cytokinin benzyladenine (BA) applied in culture and thus reduce potential side-effects. The Spiraea in vitro light quality response was characterized by examining the effects of different light wavelengths on growth. A mixture of red/FR induced rates of shoot proliferation with 0.25 mg/1 BA that were as high as rates obtained under white light with 0.5 mg/1 BA. Shoot quality, as determined by the proportion of shoots 1 cm or longer (useful shoots), was highest under red/FR light. The lowest shoot proliferation rate was observed under blue light. When light wavelengths intermediate between blue and red light (green, yellow, and orange) were applied to explants only minor growth modifications occurred. Green light did not inhibit shoot initiation but inhibited shoot elongation at the 0.5 mg/1 BA level. The efficacy of the light source-filter combinations in the first experiment was studied in two further experiments. With the three light sources (tungsten filament, fluorescent, and metal halide) together with a blue filter, results supported the putative blue light inhibitory effect suggested in the first light quality experiment. Under the red filter, the tungsten filament source induced the highest shoot number means at both BA levels used (0.25 and 0.5 mg/1). Two factors may have contributed to the red/FR effect observed in the first experiment; the time under an incubation light regime before transfer to the treatment regime, and the photon fluence rate of each regime. In the subsequent study to examine these factors, shoot initiation was optimized at the lower BA levels of 0.25 and 0.4 mg/1 when cultures under low fluence red/FR were transferred after four weeks to white light of a higher fluence for one more week. Glyphosate, a known promoter of IAA oxidation, was used to investigate the presumed effect of lowered IAA-cytokinin interactions. Two types of responses to glyphosate occurred, each one dependent on the glyphosate concentration. At the lower glyphosate level (0.087 mg/1), cultures under both light regimes with 0.25 mg/1 of BA, showed a strong inhibition of shoot initiation. This inhibitory effect was overcome in cultures with 0.5 mg/1 of BA and an overall stimulatory response occurred as shoot initiation rates were as much as four-fold higher than in the previous experiments. For both BA levels, changes in shoot number were greater under white light than under red/FR. At the higher glyphosate level (0.2 67 mg/1), the shoot initiation rates were greater than glyphosate-free controls for both BA levels under white light although under red/FR the rates were virtually unchanged from controls. The glyphosate effect investigated for Spiraea cultures appears to be influenced by the levels of the cytokinin BA resulting in pleiotropic effects which depend on the specific concentrations of each component. / Land and Food Systems, Faculty of / Graduate

Typescript. / Bibliography: leaves 158-169. / Photocopy. / Microfilm. / xviii, 169 leaves, bound ill. 29 cm

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Graduation date: 1993

The effects of one night of 3h sleep on cortisol levels were assessed in two groups of women at different points in their menstrual cycles: mid-follicular and mid-luteal. Eighteen women (age: 21.8 ± 0.54; BMI: 22.6 ± 0.63, mean ± SEM) were studied. Salivary samples were collected at six times during two consecutive days: first after a 10 h overnight sleep opportunity and then after a night with a 3 h sleep opportunity. Secondary analysis examined the impact of sleep restriction on self-reports of hunger ratings and mood. Women in the follicular phase showed a significant decrease (p =0.004) in their cortisol awakening responses after sleep restriction and an elevation in afternoon/evening cortisol levels (p =0.008), whereas women in the luteal phase showed no change. Overall group increases in hunger and deterioration in fatigue and vigour were observed. Menstrual cycle phase dramatically altered the responses of women to a single night of sleep restriction.

Thyroxine was observed to stimulate the incorporation of radio labeled amino acids into protein of cell-free Liver systems from treated normal and hypothyroid rats. However, the in vitro addition of the hormone only had a stimulatory effect, though quite erratic in magnitude, on the normal system. This difference in response has not been explained. The hypothyroid rat was also characterized by lowered liver ribonucleic acid levels. It WEB found that thyroxine pretreatment resulted in increased ribonucleic acid levels only in the hypothyroid rat with the greater increase occurring in microsomal ribonucleic acid. No change was observed in the ribonucleic acid base ratios of the hypothyroid rat when compared to those of the normal. However, thyroxine pretreatment cf the hypothyroid rat did alter the rate of incorporation of radio phosphorus into the various nucleotides, although there was little difference in the total amount of incorporated label. / Ph. D.

Vitamin D is a precursor to a steroid hormone, 1,25 dihydroxyvitamin D (1,25(OH)2D). After its discovery and the characterization of its receptor, the vitamin D receptor (VDR), it was initially thought only to be involved in calcium homeostasis, but further research revealed an important role for vitamin D in the regulation of cell growth and differentiation of such cells as osteoblasts and bone marrow adipocytes. 1,25(OH)2D has also been shown to be a strong inhibitor and pro-differentiator of keratinocytes. The anti-proliferative and pro-differentiative properties of this hormone have led to studies where 1,25(OH)2D anticancer properties were assessed and initial findings that showed a requirement of other factors beyond VDR to induce 1,25(OH)2D signaling led to the identification of the retinoid X receptor, a common heterodimeric partner for several hormone receptors. The focus of thesis was to further elucidate the structure-function relationship of both the vitamin D receptor and the retinoid X receptor. Additionally, contributions to work directed towards further identifying the effects of vitamin D on osteoblast differentiation and survival. Interactions of 1,25(OH) 2D3 with its cognate receptor, identifying a key amino acid (Tryptophan 286) required for ligand contact and transcriptional activation, are described in Chapter 2. Mechanisms of vitamin D action on mesenchymal stem cell differentiation, promotion of osteoblast induction and maturation, and inhibition of adipocyte differentiation, are eluicidated in Chapter 3. Chapter 4 illustrates the effects of RAS/RAF/Mitogen-activated protein kinase mediated RXRalpha phosphorylation on the three-dimensional structure of the RXR/nuclear receptor partner heterodimers. Furthermore, this chapter reveals the inhibitory effect of the phosphorylation of a critical amino acid (serine 260) on the interaction of the AF-2 domain of the RXR with several coactivators, resulting in a decrease in the signaling potential of multiple steroid hormone receptors. The findings of this thesis further the knowledge of several areas of vitamin D biology, including both the canonical areas of bone formation, and the non-canonical area of vitamin D and cancer.

Orientador: Patricia de Oliveira Prada / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-25T21:25:58Z (GMT). No. of bitstreams: 1 Reis_SabrinaKaren_M.pdf: 2044889 bytes, checksum: 02eeb1437ecda9df9b2500ae61a282e8 (MD5) Previous issue date: 2014 / Resumo: Obesidade está associada à inflamação crônica de baixo grau e ao desenvolvimento da resistência à insulina. A suplementação com L-glutamina tem sido utilizada para reduzir a inflamação em pacientes críticos. No entanto, os efeitos da suplementação deste aminoácido em doenças inflamatórias de baixo grau, como a obesidade, ainda não foram investigados. Por tanto o objetivo do presente estudo foi investigar se a suplementação oral com L-glutamina altera a massa corporal, circunferência da cintura, sensibilidade à insulina e os níveis séricos de hormônios relacionados ao metabolismo energético em indivíduos com sobrepeso e obesidade. Foi realizado um estudo clínico randomizado, simples cego com 67 voluntários adultos do Hospital Estadual de Sumaré (HES), classificados com sobrepeso (IMC 25 a 29,9 kg/m²) ou obesidade (IMC ? 30). Os indivíduos foram suplementados com 30 g/dia de glutamina ou alanina durante 14 dias. Os níveis séricos de insulina, leptina, adiponectina e GLP-1 foram avaliados no período pré e pós-suplementação, pelo método de ELISA. A glicose sérica foi avaliada pelo método da glicose oxidase. O índice de HOMA foi calculado. A massa corporal, o índice de massa corporal (IMC), a circunferência da cintura e o recordatório alimentar de 24 horas, também, foram avaliados pré e pós-suplementação. A suplementação oral com L-glutamina não alterou a massa corpórea e o IMC, no entanto reduziu a circunferência da cintura e os níveis séricos de leptina, sugerindo uma diminuição na massa adiposa. Não houve diferença significativa nos níveis séricos de glicose, adiponectina e GLP-1. Entretanto, houve uma redução nos níveis séricos de insulina e índice de HOMA, sugerindo uma redução na inflamação de baixo grau e uma melhora na sensibilidade à insulina. Os dados obtidos sugerem que a suplementação oral com L-glutamina em um curto período de tempo pode reduzir a massa adiposa de indivíduos com sobrepeso e obesidade. Essa redução refletiu nos níveis séricos de leptina e provavelmente nos níveis séricos de insulina, melhorando a sensibilidade à insulina. Por tanto, a suplementação com L-glutamina pode tornar-se uma abordagem terapêutica interessante para os indivíduos com sobrepeso e obesidade / Abstract: Obesity is associated with low-grade inflammation and insulin resistance. Glutamine supplementation has been used to reduce inflammation in critically ill patients. However, the effects of glutamine supplementation were not yet investigated in diseases with lowgrade inflammation such as obesity. Previous data showed that glutamine supplementation reduced inflammation, adipose mass and improved insulin sensitivity of obese rats. Thus, the aim of this study was to investigate whether oral glutamine supplementation alters body weight (BW), waist circumference (WC) and hormones levels and insulin sensitivity in overweight and obese humans. A randomized clinical trial, single blind with 67 adult volunteers from the State Hospital of Sumaré (HES), classified as being overweight (IMC 25 a 29,9 kg/m²) or obese (IMC ? 30) was performed. The subjects were supplemented with 30 g / day glutamine or alanine for 14 days. Serum levels of insulin, leptin, adiponectin and GLP-1 were evaluated before and after supplementation, by ELISA. Serum glucose was measured by glucose oxidase method. The HOMA index was calculated. The body weight, body mass index (BMI), waist circumference and 24-hour food record were also evaluated before and after supplementation. Glutamine supplementation did not change BW and BMI, however, reduced WC and serum leptin levels, suggesting a decrease in fat mass. Glutamine supplementation l did not alter serum adiponectin, GLP-1 and glucose levels. However, was reduced insulin levels and HOMA index, suggesting a reduction in low-grade inflammation associated with an improvement of insulin sensitivity. The data suggest that oral supplementation with L-glutamine in a short period of time can reduce fat mass in overweight and obese individuals. This reduction reflected in serum leptin levels and probably in serum insulin levels, improving insulin sensitivity. Thus, glutamine supplementation may become an interesting therapeutic approach for individuals with overweight and obesity / Mestrado / Nutrição / Mestra em Ciências da Nutrição e do Esporte e Metabolismo

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