No description available.

No description available.

No description available.

No description available.

Mammalian reproduction is vulnerable to psychological and physiological stress. This research focuses on the psychophysiological mechanisms that lead to the disruption of pregnancy by the failure of implantation of fertilized ova into the uterine walls. The underlying hormonal mechanisms of implantation failure are not well understood. It is known that many environmental events have a substantial impact on hormonal dynamics in mammals. These environmentally induced hormonal changes can disrupt implantation. This thesis focuses on the hormonal dynamics of female mice that lose their pregnancy when exposed to a novel male during the implantation period (the Bruce effect). In Study 1, a repeatable and reliable Bruce effect was established by indirectly exposing inseminated females during the implantation period to novel males housed above them separated by a wire grid floor. Separating the animals allowed for the independent study of the chemical transmission from male to female, and the physiological transduction within the female. The findings from this study suggest that females must come in direct contact with the excretions of the stimulus novel males. The more excretions the females encounter, the greater the chance is of pregnancy disruption. The Bruce effect is known to be dependent on androgens in the stimulus males, since castration eliminates their capacity to disrupt pregnancy. Study 2 showed that surgically removing the androgen-dependent preputial glands from the stimulus males does not diminish their capacity to disrupt pregnancy. Study 3 showed that administering 17β-estradiol to castrated males can restore their capacity to disrupt pregnancy. This suggests that 17β-estradiol as well as testosterone is involved in the chemical transmission of the Bruce effect. It has been hypothesized that 17β-estradiol is elevated in females that fail to implant in the presence of a novel male. Administering an antibody specific to 17β-estradiol to females during their implantation period can lower the hypothesized increase in 17β-estradiol and implantation takes place despite the exposure to novel males. Finally, in Study 4 testosterone, 17β-estradiol and its major metabolites the estrone conjugates were quantified in females' urine and feces while exposed to novel males during implantation. It was found that testosterone and 17β-estradiol were significantly elevated in females that failed to implant while exposed to novel males. In conclusion, this line of research reveals a potential role of steroids in novel male induced pregnancy disruptions in mice. Elevated testosterone and 17β-estradiol are shown to be related to the prevention of implantation in mice. These hormonal dynamics may be partially responsible for the physiological transduction of the Bruce effect. / Thesis / Doctor of Philosophy (PhD)

No description available.

The purpose of this investigation was to determine the comparability of flexible endoscopy to rigid endoscopy in the examination of rabbit vocal folds in vivo. This work was conducted within a larger parent project that has investigated the adverse effects of combination inhaled corticosteroids (ICs) on voice function in animal models and humans. In this study, both flexible and rigid vocal fold imaging was performed on eight rabbits; four having received ICs and four that were from control conditions. Original recordings were examined frame-by-frame to identify similar views, zoomed in and zoomed out, for flexible and rigid samples. Images were extracted, cropped, and placed in a slide presentation for purposes of visual-perceptual ratings. Two board-certified laryngologists from the parent project performed ratings that included the following: (a) superiority or equivalence (>, <, or =) of randomized rigid and flexible images; (b) erythema severity using a visual analog scale (VAS) for all randomized images; and (c) edema severity using VAS for all randomized images. Each rating was performed twice, in random order, for purposes of computing interjudge and intrajudge reliability. The results indicated that images from rigid endoscopy were of superior quality than those from flexible endoscopy. Additionally, the magnitude of severity ratings was greater for flexible versus rigid images. These findings offer confirmatory evidence that rigid endoscopy remains the preferred method for endoscopic analysis; however, flexible endoscopy is a novel, viable alternative that permits reliable visual-perceptual analysis during in vivo small animal voice research.

O presente trabalho descreve o isolamento e a identificação ou determinação estrutural de metabolitos secundários de folhas e raízes ou rizomas de espécies de aráceas, coletadas na Reserva de Picinguaba, no Estado de São Paulo. O material vegetal forneceu, após extração com hexano, etanol e etanol aquoso, os seus respectivos extratos. A composição de ácidos graxos presentes nos extratos hexânicos foram analisados por CG/EM, observando-se a predominância do ácido palmítico, tanto nas folhas, quanto nas raízes de todas as espécies estudadas. A partição dos extratos brutos com solventes orgânicos e o fracionamento cromatográfico de resíduos das fases resultantes permitiram o isolamento de fitil, fitol, palmitato de sitosterol, 3&#946;-palmitoxil-colest-5-en-7-ona, colest-4-en-3-ona e coleste-4,22-dien-3-ona, a-tocoferol, sitosterol + estigmasterol, 3&#946;-hidroxicolest-5-en-7-ona + 3&#946;-hidroxi-coleste-5,22-dien-7-ona,p-hidroxibenzaldeído, ácido phidroxibenzóico, acilglicosil sitosterol, acilglicosil 3&#946;-hidroxi-colest-5-en-7-ona, acilglicosil + 3&#946;-hidroxi-coleste-5,22-dien-7-ona, acilglicosil 3&#946;,8-dihidroxi-coleste-5-en-7-ona, e glicosil-sitosterol + glicosil-estigmasterol. A elucidação estrutural das substâncias isoladas foi baseada em métodos éspectrométricos, sobretudo na ressonância magnética nuclear de hidrogênio e de carbono 13. / The present work describes isolation and identification or structural elucidation of secondary metabolites from the Ieaves and roots or tubers of Araceae species which were collected in the Pinciguaba Reserve, São Paulo State, Brazil. The extraction of plant materiaIs with hexane, ethanoI, water-ethanol, yielded its respective extracts. The composition of fatty acids present in the hexane extracts was carried out on GC/MS and it was observed that palmitic acid was the major constituent in Ieaves and roots or tubers of all analysed species. The partition of the crude extracts with organic solvent and chromatographic fractionation of residues afforded phytyl, phytol, &#946;-sitosteryl palmitate, 3&#946;- palmitoxyl-cholest-5-en-7-one, choleste-4-en-3-one + choleste-4,22-dien-3-one, (1,- tocopherol, sitosterol + stigmasterol, 3&#946;-hydroxy-cholest-S-en-7 -one + 3&#946;-hydroxy-cholest-5,22-dien-7-one, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, acylglucosyl sitosterol, acylglucosyl 3&#946;-hidroxy-cholest-5-en-7-one, acylglucosyl 3&#946;-hidroxy-cholest-5 ,22-dien-7-one, acylglucosyl 3&#946;,8-dihydroxy-cholest-5-en-7 -one, 3&#946;-O-&#946;-D-glucopyranosylsitosterol + 3&#946;-O-&#946;-D-glucopyranosylstigmasteroI. The structural elucidation of isolated metabolites was performed by spectrometric techniques, mainly by 1H and 13C NMR.

This thesis describes biochemical and molecular methods diagnostic for a spectrum of steroid metabolic diseases. Deficiency of any enzyme in the steroid hormone biosynthetic pathways leads to disorders including congenital adrenal hyperplasia, while some cause disorders of sex development (DSD). A gas chromatography mass spectrometry-based analytical technique called urinary steroid profiling (USP) has been shown to be a useful diagnostic test for these diseases and for steroid-secreting adrenocortical tumours. To test the hypothesis that this approach would be effective in our local population, we interpreted 482 USP results using reference intervals set up from 371 local healthy subjects. Characteristic steroid metabolite excretion patterns were found in 39 patients, including 21 patients with 21-hydroxylase deficiency (21OHD) where there were grossly increased 17-hydroxyprogesterone metabolites, 12 patients with 5α-reductase 2 deficiency (5ARD) with extremely low 5α- to 5β-reduced steroid metabolite ratios, and five patients with adrenocortical carcinoma with markedly raised tetrahydro-11-deoxycortisol and 3,16,20-pregnenetriols levels. / The genetic basis of 21OHD in various populations is mainly due to conversion between the CYP21A2 and the CYP21A1P genes but this has not yet been explored in our population. By using DNA sequencing and multiplex ligation-dependent probe amplification, 74 mutations were found in 35 patients with 21OHD. Gross deletion/conversion of the CYP21A2 gene accounted for 27%. c.290-13A/C>G was the most common point mutation (27%), followed by p.Ile172Asn (17.6%). One novel mutation c.1367delA was also detected. Their prevalence in our patients differs from those in other populations. / The most common cause of 46,XY DSD in Western populations is androgen insensitivity syndrome (AIS) but this has not been verified locally. A prospective study was conducted where 64 patients were recruited for comprehensive hormonal profiling and targeted molecular analysis. In this study, a genetic diagnosis was established in 22 patients, with 5ARD being the most common disease, followed by AIS. Traditionally the diagnosis of 5ARD relies on measuring dihydrotestosterone. However, with our experience in diagnosing this condition based on USP and mutational analysis of the SRD5A2 gene, two new diagnostic algorithms for 46,XY DSD were proposed where dihydrotestosterone is not required. / In vitro study is the preferred method for characterising the function of novel genetic variants. However, clinical laboratories rarely have the facilities and resources for it. In silico prediction programmes appear to be practical alternatives but their performance on testing non-synonymous variants in genes related to steroid metabolism has not been verified. Three web-based in silico prediction programmes, namely Sorting Intolerant From Tolerant, PolyPhen-2 and Pathogenic-Or-Not-Pipeline, were tested by analysing 797 published non-synonymous genetic variants in 12 genes related to steroid metabolism. The results of in vitro functional study and/or clinical phenotype were used as gold standards. The performance of these three programmes were: sensitivity (76.6%, 84.1%, 70.0%), specificity (56.6%, 56.3%, 89.4%) and accuracy (70.1%, 75.2%, 76.8%), respectively. / In conclusion, USP is a valuable biochemical phenotyping technique that helps to select patients for subsequent genetic confirmation. Since the mutation spectrum of 21OHD and the aetiological basis of 46,XY DSD in our population differ from the others, laboratory diagnostic algorithms and molecular analytical strategies must be adjusted accordingly. / Chan, On Kei Angel. / Thesis (M.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 250-269). / Appendixes includes Chinese.

O presente trabalho descreve o isolamento e a identificação ou determinação estrutural de metabolitos secundários de folhas e raízes ou rizomas de espécies de aráceas, coletadas na Reserva de Picinguaba, no Estado de São Paulo. O material vegetal forneceu, após extração com hexano, etanol e etanol aquoso, os seus respectivos extratos. A composição de ácidos graxos presentes nos extratos hexânicos foram analisados por CG/EM, observando-se a predominância do ácido palmítico, tanto nas folhas, quanto nas raízes de todas as espécies estudadas. A partição dos extratos brutos com solventes orgânicos e o fracionamento cromatográfico de resíduos das fases resultantes permitiram o isolamento de fitil, fitol, palmitato de sitosterol, 3&#946;-palmitoxil-colest-5-en-7-ona, colest-4-en-3-ona e coleste-4,22-dien-3-ona, a-tocoferol, sitosterol + estigmasterol, 3&#946;-hidroxicolest-5-en-7-ona + 3&#946;-hidroxi-coleste-5,22-dien-7-ona,p-hidroxibenzaldeído, ácido phidroxibenzóico, acilglicosil sitosterol, acilglicosil 3&#946;-hidroxi-colest-5-en-7-ona, acilglicosil + 3&#946;-hidroxi-coleste-5,22-dien-7-ona, acilglicosil 3&#946;,8-dihidroxi-coleste-5-en-7-ona, e glicosil-sitosterol + glicosil-estigmasterol. A elucidação estrutural das substâncias isoladas foi baseada em métodos éspectrométricos, sobretudo na ressonância magnética nuclear de hidrogênio e de carbono 13. / The present work describes isolation and identification or structural elucidation of secondary metabolites from the Ieaves and roots or tubers of Araceae species which were collected in the Pinciguaba Reserve, São Paulo State, Brazil. The extraction of plant materiaIs with hexane, ethanoI, water-ethanol, yielded its respective extracts. The composition of fatty acids present in the hexane extracts was carried out on GC/MS and it was observed that palmitic acid was the major constituent in Ieaves and roots or tubers of all analysed species. The partition of the crude extracts with organic solvent and chromatographic fractionation of residues afforded phytyl, phytol, &#946;-sitosteryl palmitate, 3&#946;- palmitoxyl-cholest-5-en-7-one, choleste-4-en-3-one + choleste-4,22-dien-3-one, (1,- tocopherol, sitosterol + stigmasterol, 3&#946;-hydroxy-cholest-S-en-7 -one + 3&#946;-hydroxy-cholest-5,22-dien-7-one, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, acylglucosyl sitosterol, acylglucosyl 3&#946;-hidroxy-cholest-5-en-7-one, acylglucosyl 3&#946;-hidroxy-cholest-5 ,22-dien-7-one, acylglucosyl 3&#946;,8-dihydroxy-cholest-5-en-7 -one, 3&#946;-O-&#946;-D-glucopyranosylsitosterol + 3&#946;-O-&#946;-D-glucopyranosylstigmasteroI. The structural elucidation of isolated metabolites was performed by spectrometric techniques, mainly by 1H and 13C NMR.