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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metabolism of methionine in women using oral contraceptives

Dow, Marjorie J. 27 May 1975 (has links)
The effect of oral contraceptives on the urinary excretion of several methionine metabolites was determined in women before and after they had received a 3-g dose of L-methionine. Nine women between the ages of 20-29 years served as subjects: five had been using a combination-type oral contraceptive for six months or more (experimental group), and four had not been using these drugs (control group). Cystathionine excretion by both groups before and after the methionine loading was in the range reported for normal female subjects who were not deficient in vitamin B₆ (Krishnaswamy, 1972; Shin and Linkswiler, 1974). Changes in urinary methionine metabolites that were apparently produced by oral contraceptive drugs are: (1) homocysteine was detected in the basal urine of three of the oral contraceptive users. After methionine loading, it was found in the urine of four of these subjects, two of whom excreted measurable quantities. In contrast, three of the control subjects excreted traces of homocysteine only after methionine loading. (2) The mean excretion of taurine by oral contraceptive users was only one-tenth of that excreted by the control subjects. The activity of erythrocyte glutamic oxaloacetic transaminase (EGOT) before and after in vitro stimulation with added pyridoxal phosphate was similar in both groups. Basal activity of erythrocyte glutamic pyruvic transaminase (EGPT) was lower in oral contraceptive users, although the mean values for both groups were within the normal range reported by Miller et al. (1975) and Woodring and Storvick (1970). The percent in vitro stimulation after addition of pyridoxal phosphate was somewhat higher in oral contraceptive users, but the difference was not statistically significant. Thirteen free acidic and neutral amino acids (including metabolites of the methionine pathway) were measured in the urine specimens. The sum of the urinary excretion of these 13 amino acids was significantly lower (p < 0.01) for oral contraceptive users than for control subjects. However, total α-amino nitrogen excretion, measured in the same urine specimens, was similar for both groups. / Graduation date: 1976
2

Effect of oral contraceptives in women on the plasma and urinary levels of vitamin B₆

Kokkeler, Shelly Carol 11 June 1975 (has links)
The effect of oral contraceptives on urinary and plasma vitamin B₆ as well as erythrocyte transaminase activities was investigated in women. Five women who were taking oral contraceptives and four who were not using these drugs served as subjects. They were apparently healthy and free from any known metabolic disorder. The subjects, who consumed normal diets, recorded their dietary intake for three days. Twenty-four hour urine specimens were collected on two consecutive days by the subjects. On the morning of the second day blood for the various biochemical measurements was drawn from fasting subjects. Following the blood drawing the women were given an oral dose of 3 g of L-methionine. Results of the methionine load test are reported elsewhere. The subjects consumed diets that supplied at least two-thirds or more of their National Academy of Science-National Research Council (1974) Recommended Dietary Allowances (RDA) for most nutrients except iron and vitamin B₆. The mean dietary intake of vitamin B₆ was 1.57 mg per day for the untreated women and 1.52 for the oral contraceptive users. On both days the mean levels of free and total vitamin B₆ in urine were less in the oral contraceptive users than that in the untreated controls, but the differences were not statistically significant. There appeared to be some relationship between dietary intake of vitamin B₆ and urinary excretion of the vitamin. The methionine loading dose did not affect the excretion of vitamin B₆ The mean plasma level of vitamin B₆ was lower for the oral contraceptive users than for the untreated controls although the difference is not statistically significant. There was, however, a large variation in values among the subjects taking oral contraceptives. Two of them had extremely low plasma vitamin B₆ levels. Vitamin B₆ in the plasma did not appear to be related to dietary intake or urinary excretion of the vitamin. Erythrocyte glutamic oxaloacetic transaminase (EGOT) and erythrocyte glutamic pyruvic transaminase (EGPT) activities with and without in vitro stimulation with pyridoxal phosphate (PALPO) were also measured. There were no significant differences between the two groups in EGOT and EGPT activities with and without in vitro stimulation. According to the activity indexes (PALPO stimulated activity/activity without added PALPO) for EGOT and EGPT (Sauberlich et al., 1972), all subjects had adequate vitamin B₆ nutritional status. Activity indexes for EGOT and EGPT did not appear to be related to urinary or plasma levels of vitamin B₆ Urinary and plasma vitamin B₆ levels and erythrocyte trans- aminase activities were not related to the length of time the women had been taking oral contraceptives or the estrogen content of their oral contraceptive agent. / Graduation date: 1976
3

Nutrition during oral contraceptive treatment

Siu, Annie Chi-Yee January 2010 (has links)
Typescript, etc. / Digitized by Kansas Correctional Industries
4

Secondary effects of oral contraceptives

Yuen, E Ho January 1978 (has links)
Norethynodrel, a common progestin in oral contraceptives, produces in female rats several significant physiological, cytological and biochemical changes at dose levels of 1 mg and 20 mg per kg: 1) a relative increase in liver mass 2) modification of appearance and extent of the endoplasmic reticulum 3) augmentation of the protein content of the liver 4) increase of the level of cytochrome P- 450 in the liver as determined by : a) difference spectroscopy b) increases in biotransformation of aniline and aminopyrine in vitro and c) reduction of sleeping times of rats dosed with phenobarbital The significance of these findings becomes evident when it is realized that norethynodrel affects and is affected by the same enzyme system which oxidizes medicaments in general in the body: induction of cytochrome P-450 by administration of norethynodrel may interfere with the action of other drugs . Ethinyl estradiol alone showed none of the inductive effects. At high dose levels (20 mg per kg) both norethynodrel and ethinyl estradiol caused a marked inhibition of growth of the animals, producing a net loss of body mass over the 30- day experimental period. Electron micrographic evidence implies that there is also a lowering of glycogen content and a chemical change in the lipids of adrenocortical and liver cells accompanying the use of these agents.
5

THE EFFECT OF LONG-TERM ORAL CONTRACEPTIVE THERAPY PRIOR TO PREGNANCY ON MATERNAL AND FETAL ZINC STATUS.

Beard, Lisa Powell. January 1983 (has links)
No description available.
6

Oral contraceptives, weight control, and fat patterning in young college women

Litchfield, Ruth Edson January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas State University Libraries / Department: Foods and Nutrition.
7

Potential influences of oral contraceptive use and physical activity on bone health : a one-year prospective study in young women

Almstedt Shoepe, Hawley Chase 19 April 2005 (has links)
Osteoporosis is a skeletal disease affecting 44 million Americans. A primary strategy to prevent osteoporosis is to develop a high peak bone mass in youth. Oral Contraceptives (OCs) alter hormones in women and could affect bone mass development. The interaction between OCs and skeletal mineralization is poorly understood. PURPOSE: Our aims were to 1) compare bone mineral density (BMD) of young women who had a history of OC use with regularly menstruating controls, 2) compare changes in BMD in controls, women who initiate OC use, and those who have a history of use, and 3) to evaluate predictive capabilities of physical activity and years of oral contraceptives use on changes in BMD. METHODS: We recruited women, 18 to 25 years of age, with a history of OC use and controls. BMD at the hip, whole-body, and spine (AP, g/cm�� and width-adjusted lateral, g/cm��) was measured by dual-energy x-ray absorptiometry. Physical activity (METs) was measured via questionnaire and grip strength was evaluated using an isometric dynamometer. RESULTS: Groups were similar in body mass index (BMI), fat mass, grip strength, calcium intake and physical activity but controls were slightly older than OC users. In analysis of covariance (ANCOVA), controlling for age and BMI, controls had significantly greater BMD than OC users at baseline at the AP and lateral spine, hip, and whole-body (p<0.05). By ANCOVA (covariates = age at baseline, change in weight), oral contraceptive users had greater bone loss at L��� in the lateral view than controls whereas, controls had greater increases in L��� volumetric BMD, BMD of the total hip, and whole body than OC users (p<0.05). Stepwise regression results did not reveal years of oral contraceptive use, grip strength, or METs to be a significant predictor of changes in BMD at any site. CONCLUSIONS: We conclude that, in the cross-sectional analysis, oral contraceptive use by young women may compromise bone health during a time when mineral is still accruing. In the prospective analysis, regularly menstruating controls had greater BMD accrual or less bone loss over a 12-month time period than women with a history of oral contraceptive use. / Graduation date: 2005
8

The effects of contraceptives on the anti-oxidant status, skin parameters and anthropometric indicators in female students: a pilot study

Germishuys, Martha Petronella January 2019 (has links)
Thesis (MSc (Biomedical Technology))--Cape Peninsula University of Technology, 2019 / Introduction: The provision of access to safe and effective contraception is a critical element in the health of women that enables them to make choices about their fertility. This element of control empowers them and indirectly enables them to access better social and economic opportunities. Hormonal contraceptives are a convenient, effective and relatively safe method of fertility control. Extensive research has been done on the effects of hormonal contraceptives on undesirable metabolic and haemostatic changes, but data on the relationship between oxidative stress and oral contraceptives is scarce and remains subject to debate. Aging of the skin due to oestrogen loss at menopause is thought to include atrophy, decreased collagen content, water content, and sebaceous secretions, loss of elasticity, wrinkling, poor wound healing and manifestations of hyperandrogenism. A number of studies have shown that oestrogens serve many important beneficial and protective functions in skin physiology. Despite extensive clinical experience, many metabolic effects of oral contraceptive treatment remain to be explored. The effects of progesterone on body weight and composition are of interest from several standpoints. Since hormonal contraceptives are widely used, it is important to investigate the effect thereof on oxidative status, skin parameters and anthropometric indicators, to enable women make informed choices about the use of contraceptives, or to adapt their lifestyle if necessary. The aim of the present study was therefore, to assess certain effects of contraceptives in a student population at the Cape Peninsula University of Technology (CPUT). Objectives of the study: To determine the differences in skin health, anthropometric \parameters and oxidative stress status in female university students using various hormonal contraceptives versus non-contraceptive users. Research design: The study adopted a quantitative approach to examine a crosssectional research sample in order to provide a snapshot of the population at a particular time. Concenting participants were selected through the use of questionnaires aimed at ascertaining the type of contraceptive used as well as general health and lifestyle patterns. Blood samples were collected and the antioxidant status was determined. Body composition and skin analysis was conducted on each of the participants in the selected groups and the results were compared to determine the differences between contraceptive and non-contraceptive users. Results: With regards to oxidative stress status, the results indicated a significant increase in superoxide dismutase (SOD) activities within the triphasic contraceptive group compared to the monophasic contraceptive group, suggesting higher levels of oxidative stress in monophasic contraceptive groups. There was also an increase in lipid peroxidation (TBARS) for the triphasic contraceptive group when compared to the control, monophasic contraceptive and injectable contraceptive groups respectively, indicative of increased oxidative stress levels in the triphasic contraceptive group. In this study, skin parameters evaluation revealed that there was a general increase in the presence of erythema in the monophasic contraceptive group compared to the control; injectable contraceptive; implant contraceptive and triphasic contraceptive groups, symptomatic of higher vascular activity in the monophasic group. Melanocyte activity measured in the forehead, cheek and chin areas were also significantly increased when the monophasic contraceptive group was compared to the control and other contraceptive groups, characterised by the pigmentation pattern of chloasma/melasma known to be caused by hormones. The hydration measurements were significantly increased in the implant contraceptive group compared to the control and monophasic contraceptive groups. Furthermore, a significant increase in hydration was evident in the injectable contraceptive group when compared to the control and monophasic contraceptive groups. Injectable contraceptives and implant contraceptives mainly contain progesterone which has been proven to combat signs of aging and increase collagen and elastin in the skin. With respect to anthropometric measurements, there was a significant increase in the measurement of waist to hip ratio in the implant contraceptive group compared to the control group (non-contraceptive). Progesterone influence on adipose tissue distribution indicated a more significant increase of adipose tissue in the abdominal region. Conclusion: In this study there was some evidence that the type of hormonal contraceptive used does have significant effects on the variables tested in the population sample. These effects are dependent on the composition of the contraceptive and the levels of progesterone and/or oestrogen.

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