The object of this study is to determine the intake (in food) and output (in feces) of vitamin A and carotene of several groups of college women living in the Home Management House.

No description available.

Call number: LD2668 .T4 1953 B65 / Master of Science

Call number: LD2668 .T4 1965 H78 / Master of Science

Maternal obesity is an increasing concern in the obstetric population. It confers increased morbidity and mortality to the mother and offspring during pregnancy and delivery as well as potential long-term increase in risk of ill health to the offspring. There are currently few effective interventions and no pharmacological therapies. Potential mechanisms to account for ill health in obese non-pregnant individuals include excess inflammation, both systemically and within specific tissues such as adipose, as well as alterations in metabolic regulation including hyperglycaemia, reduced sensitivity to insulin and altered adipokine expression. In healthy pregnancy, there are significant adaptations to maternal metabolism, including the development of profound systemic insulin resistance. We hypothesize that there exists an interaction between the metabolic adaptations of pregnancy and those occurring in obesity which could provide a physiologically plausible mechanism which could contribute to the pathogenesis of adverse outcomes associated with obese pregnancies. In this thesis, we sought to understand and define the metabolic adaptations to pregnancy in severely obese women. Anthropometric characteristics are described in a longitudinal case-control study of apparently healthy obese (BMI > 40kg/m2) pregnant women. Systemic adipokine and pro- inflammatory cytokine profiles were measuring using ELISA. Indices of insulin sensitivity were assessed at three time points in pregnancy. In a cohort study of healthy pregnant women in the third trimester, transcript levels of adipokines and inflammatory cytokines in paired subcutaneous and omental adipose tissue biopsies were quantified and correlated these transcript levels with booking body mass index (BMI). Obese pregnant women gained less weight in pregnancy compared to lean women, but had significantly elevated fasting third trimester glucose, as well as elevated blood pressure and fasting insulin resistance throughout pregnancy. Fasting leptin was elevated throughout pregnancy in obese compared with lean pregnancy women; however, in the third trimester there was no correlation between adipose tissue leptin mRNA levels and BMI. Transcript levels of IL-6 were positively correlated with BMI in subcutaneous but not omental adipose tissue; no other positive correlations with BMI were shown. Hyperinsulinaemic euglycaemic clamps with concomitant use of stable isotope tracers were carried out in a case-control study of healthy obese pregnant women to characterise in detail whole body insulin sensitivity, endogenous glucose production and rate of lipolysis. In contrast to the original hypothesis, by the third trimester, there were few differences between lean and obese pregnant women in whole body glucose disposal (WGD) and endogenous glucose production. Compared with non-pregnant women, lean pregnant women demonstrated approximately 60% decrement in WGD; in contrast, obese non-pregnant women were already significantly insulin resistant but did not develop further insulin resistance in response to pregnancy. 3-Tesla (3T) Magnetic Resonance Imaging (MRI) and 1H-Magnetic Resonance Spectroscopy (1H-MRS)was used to assess abdominal fat distribution, hepatic and skeletal muscle lipid content in a case-control study of healthy pregnant women in the third trimester. As expected, obese pregnant women have greater adipose accumulation in both subcutaneous and intra-abdominal adipose depots and greater lipid accumulation in skeletal muscle. However, hepatic lipid content was low in both groups and there were no significant differences between lean and obese pregnant women. This was not expected as both groups are profoundly insulin resistant at this at this gestation, and in non-pregnant individuals, insulin resistance at this level would be expected to drive hepatic lipid accumulation, and may point to a pregnancyspecific hepato-protective mechanism. In conclusion, in this thesis, it has been shown that while obese women are insulin resistant with an adverse metabolic profile, that there does not appear to be the expected worsening of this profile in response to pregnancy and that by the end of pregnancy, lean women have a similar phenotype. Instead, while lean women are exposed to this environment only towards the end of pregnancy, obese women and their offspring are exposed throughout gestation, including key periods of fetal development in early pregnancy. This prolonged exposure may account for the excess pathologies in such pregnancies, potentially by exhausting what physiological reserve such women have pre-pregnancy. Potential therapies must therefore be optimally timed to improve the metabolic profile of obese women in early pregnancy, without hindering the required adaptations of the third trimester.

M. methulotrophus is a Gram negative obligate methylotroph depending on the presence of reduced carbon compounds containing one or more carbon atoms, but containing no carbon-carbon bonds. This organism can synthesize all its cellular constituents from methanol, trimethylamine, dimethylamine, or methylamine. Conversion of methanol and the methylated amines to cell carbon involves the ultimate oxidation to formaldehyde and ammonia. While the methanol dehydrogenase is produced constitutively, the enzymes involved in the assimilation of the methylated amines are inducible. All three enzymes of the trimethylamine pathway are always induced regardless of the methylated amine substrate. Transposon mutagenesis was used to generate mutations in M.methylotrophus and an antibiotic selection procedure used to isolate mutants defective specifically in the trimethylamine pathway. Two mutants were characterised and subjected to further study. The mutant tmd 3 was unable to utilise trimethylamine, dimethylamine or methylamine as substrates and was shown to lack trimethylamine dehydrogenase by polyacrylamide gel electrophoresis. Enzyme studies confirmed the lack of the dehydrogenase within the mutant cells. The mutant mad 1, unable to use methylamine as a substrate, was shown via enzyme studies to contain trimethylamine dehydrogenase, and dimethylamine dehydrogenase, but to lack methylamine dehydrogenase activity. Molecular cloning of wild-type M. methylotrophus DNA in a broad host-range plasmid vector was used to isolate DNA fragments that could replace the mad 1 defect. An 11kb fragment was isolated that fully restored methylamine dehydrogenase activity to mad 1 cells. A 2.5kb fragment was subcloned and shown, by Southern blotting with 32P-labelled In5 DNA as a probe, to contain the site of integration of the In5 insertion, located to within a few hundred base pairs of the end. DNA sequencing, now in progress, has generated 600 base pairs of sequence from either end of the subcloned fragment, within which several regions of interest were noted.

The aim of this thesis was to investigate the regulation and role of invertases in plant carbohydrate metabolism. In the first part of this thesis a molecular approach was adopted and the expression of five invertase genes were examined in different organs and in leaves of different ages in the model plant species Arabidopsis thaliana (L. ). Of the five genes examined two encoded apoplastic invertases (ATßFRUCT 1 and ATßFRUCT 2), two encoded soluble invertases with a probable vacuolar localisation (ATßFRUCT 3 and 4) while the fifth encoded an invertase with an unknown subcellular localisation (ATßFRUCT 5). Generally, Northern hybridisation assays were sufficiently sensitive for the detection of invertase gene expression in A. thaliana, however, in order to examine the expression of rare ATßFRUCT 1 and ATßFRUCT 2 mRNA the reverse transcriptase polymerase chain reaction (RT-PCR) was the method of choice. The development of an RT-PCR internal standard enabled these data to be semi-quantitative in nature. Expression analysis revealed that each of the five invertase genes were differentially regulated in A. thaliana. However, high levels of invertase gene expression were associated with tissues typically considered sinks for carbohydrate. Examination of these tissues also revealed a relationship between invertase activity and the ratio of sucrose to hexoses. Previous work has shown that certain environmental stimuli can influence invertase activity and gene expression. In this thesis the infection of A. thaliana leaves with the biotrophic pathogen Albugo candida resulted in the localised stimulation of cell-wall associated invertase activity. Examination revealed that the majority of this increase was attributable to the stimulation of the host apoplastic invertase gene, ATßFRUCT 1. Furthermore, expression of this gene was also elevated in response to mechanical leaf wounding. The high expression of ATßFRUCT 1 in sink tissues and in response to pathogenesis and wounding suggested that this gene plays an important role in establishing a supply of hexoses to tissues under a wide range of conditions. In the second part of this thesis transgenic tomato plants (prepared by Zeneca Plant Science) with a range of leaf vacuolar invertase activities were examined. There was a linear relationship between vacuolar invertase activity and the amount of leaf hexose. In plants with no detectable leaf vacuolar invertase activity there was an accumulation of sucrose. This suggests that hexoses generated in the leaves of tomato plants are the product of sucrose cycling through the vacuole. The implications of such cycling are discussed in detail.

A simple method for the configurational analysis of the four major 2'-deoxynucleoside 5'-[160, 180] phosphorothioates, (1), and adenosine 5'-[160, 180] phosphorothioate, (1a), is described. The method involves permethylation of (1,1a) with diazomethane or dimethyl sulphate, to generate the corresponding S-methyl-O-methyl phosphorothioate, (2,2a), 8P(3:1 DMF:d4-MeOH) +30ppm. Having assigned the diastereoisomers of (2,2a) to their corresponding 31P.n.m.r. resonances, the 18O-isotope is located by examination of 31P(180) isotope shifts. A larger shift, (0.05ppm), is observed on the diastereoisomer with 180 in the P-O position than in the P-OMe position, (0.02ppm). Configurations of (2,2a) were assigned by partial hydrolysis of the Sp diastereoisomer of a 1:1 mixture of the diastereoisomers of 2'-deoxyribonucleoside- or adenosine 5'-O-methyl phosphorothioate diester, (3,3a), 8P(3:1 DMF:d4-MeOH) +58ppm, by snake venom phosphodiesterase. Subsequent methylation of (3,3a) yielded correspondingly Sp-deficient samples of (2,2a). In all cases Sp(2,2a) resonates downfield of Rp(2,2a) by ca. 0.08ppm whilst Sp(3,3a) resonates upfield of Rp(3,3a) by ca. 0.12 ppm, and shows shorter retention time on reverse-phase h.p.l.c. The method is demonstrated by the stereochemical study of the hydrolysis of (3a) by bovine intestinal mucosa 5'-nucleotide phosphodiesterase, (EC 3.1.4.1), shown to proceed with overall retention of configuration at phosphorus, indicating the involvement of a covalent enzyme intermediate. Mung bean nuclease, (EC.3.1.30.1), is shown to hydrolyse 5'-O-thymidyl 3'-O-(2'-deoxyadenosyl) phosphorothioate with inversion of configuration, consistent with a single step mechanism. The iodine-mediated desulphurisation of a dinucleoside phosphorothioate, Sp 5'-O-(2'-deoxyadenosyl)-3'-Q-thymidyl phosphorothioate, occurs with epimerisation at phosphorus in aqeous pyridine, but with 75% inversion of configuration in aqueous lutidine. These results implicate pyridine as a nucleophilic catalyst in the reaction, several displacements by pyridine causing loss of configuration at the phosphorus centre prior to displacement by water. Less nucleophilic lutidine shows reduced participation, allowing direct displacement of sulphur by water.

No description available.

No description available.