• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 207
  • 136
  • 23
  • 21
  • 13
  • 6
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 492
  • 180
  • 178
  • 138
  • 85
  • 56
  • 46
  • 46
  • 45
  • 39
  • 38
  • 35
  • 32
  • 31
  • 30
  • 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.
81

Att leva med PCOS

Karlson, Johan, Vedenbrant, Pernilla January 2011 (has links)
Aim: To describe the lived experience of women with polycystic ovary syndrome (PCOS). Method: Eight scientific articles of appropriate quality were found, analyzed, condensed and synthesized. Different experiences by women with PCOS were found and ordered into themes. The findings were then anchored in associated literature and discussed. Results: Four different themes were found: Feeling different; Disturbing symptoms; Searching for answers; Care treatment. Each of these themes offered areas of improvement in regard to nursing care. Conclusions: Extra attention to the psychosocial aspects of health for women with PCOS should be taken to improve nursing care. The exchange of information between nursing staff and patients needs to be better adapted to the individual informational needs of women with PCOS.
82

Dynamics and regulation of ovarian antral follicular waves in sheep

Duggavathi, Rajesha 22 December 2004 (has links)
The focus of the present thesis was on ultrasonographic, endocrine and molecular characterization of ovarian antral follicular waves in sheep. Transrectal ultrasonography and computer assisted image analysis were used to determine the feasibility of detecting ovulation and the forming corpus luteum (CL) and to non-invasively monitor CL differentiation and growth. High resolution transrectal ultrasonography and hormone measurements were used to assess changes in numbers of small ovarian antral follicles and their relationships to the emergence of follicular waves in cyclic ewes and to correlate pulsatile secretion of gonadotropins with follicular growth in a wave, during the mid to late-luteal phase of the ovine estrous cycle. A series of experiments were conducted, using treatment with injections of ovine follicle stimulating hormone (oFSH) and measurement of serum concentrations of FSH, in cyclic and anestrous sheep, to investigate the existence of follicular dominance. We also evaluated the characteristics of secretory patterns of FSH that are critical for follicular wave emergence, in anestrous ewes. The possible existence of an endogenous rhythm of FSH secretion, independent of ovarian antral follicular dynamics, was studied in ovariectomized ewes. Finally, ovarian antral follicles at defined stages of growth in a follicular wave (based on transrectal ultrasonographic observations) were collected from separate groups of sheep by ovariectomy, to profile the expression patterns of steroidogenic enzymes (3¦Â-HSD, 17¦Á-OH and aromatase) using immunohistochemistry and gray-scale densitometric analysis. <p> The results of the present studies showed that it is possible to detect ovulation and visualize developing CL as early as 12-24 h after ovulation in the ewe. Changes in echotexture of the CL were closely associated with its morphological and functional characteristics, and we concluded that computer assisted image analysis holds promise for the noninvasive monitoring of CL differentiation and growth. Follicles reaching ovulatory diameter (¡Ý 5 mm) emerged and grew in a wave-like pattern in sheep, but without variation in the number of small follicles (1-3 mm in diameter), as seen in cattle. We concluded that all follicles that are recruited to grow beyond 2-3-mm in diameter, to 4-mm diameter in a wave, succeed in reaching an ovulatory diameter of ¡Ý 5 mm in the ewe. The emergence and growth of ovarian antral follicles in follicular waves, in sheep, do not require changes in LH secretion and may perhaps involve changes in the follicular sensitivity to LH. The largest follicle of a wave, in sheep, appears to have limited effects on other small follicles and on the time of emergence of the next follicular wave. Thus, functional dominance, as is present in cattle, may be absent in sheep. An endogenous rhythm for periodic peaks in serum FSH concentrations that is independent of ovarian follicular dynamics may exist in sheep. The expression patterns of steroidogenic enzymes, in the theca and granulosa compartments of antral follicles growing in each follicular wave in the ewe, paralleled serum estradiol concentrations, with the exception of the concentrations of 3¦Â-HSD in granulosa cells, which increased continuously from follicles 3 mm in diameter to the preovulatory follicle after the LH surge. The largest follicle of any follicular wave, irrespective of the stage of the cycle, would appear to be mature enough to ovulate if a gonadotropin surge is provided.
83

Polycystiskt ovariesyndrom : effekter av olika kostmetoder: en litteraturstudie / Polycystic Ovary Syndrome : effects of different dietary approaches: a literature review

Gustafsson, Katarina January 2013 (has links)
Bakgrund: Runt 5-10 % av kvinnor i fertil ålder har en diagnos av polycystiskt ovariesyndrom men ännu fler lider av syndromet utan en diagnos. Polycystiskt ovariesyndrom innebär att en kvinnas ena eller båda äggstockar är fyllda med cystor och att hon har en hormonstörning. Kosthållning har en betydande effekt på hur syndromet visar sig. Syfte: Se vad olika kostmetoder har för effekter på kvinnor med polycystiskt ovariesyndrom och vilken metod som är bäst. Metod: En litteraturstudie som analyserar tio vetenskapliga artiklar i fyra olika teman. Resultat: En hög-proteinkost, en kosthållning med lågt GI och ökad fysisk aktivitet ger alla tre positiva effekter på syndromet. En fettsnål kost ger mer negativa effekter än vad en fettrik kost ger. Studien visar att viktminskning också förbättrar syndromet. Slutsats: Mer forskning behövs om olika kostmetoders effekter på kvinnor med polycystiskt ovariesyndrom i större studiepopulationer och olika kostmetoder har olika effekter på hur polycystiskt ovariesyndrom visar sig. / Background: About 5-10 % of women in fertile age have been diagnosed with polycystic ovary syndrome diagnosis with many other women also having polycystic ovary syndrome without diagnoses. Polycystic ovary syndrome is a disease where a woman’s ovaries are filled with cysts, along with related hormonal disorders. Diets can help reduce the symptoms of this syndrome. Aim: See how various dietary approaches impacts on women with polycystic ovary syndrome and to see which approach is the best. Method: A literature review that analyzes ten different scientific articles. Four major themes were extracted from this review. Results: A high-protein diet, a diet with low GI and increased physical activity are three different approaches that are show to provide positive effects in people who suffer from this syndrome. Low-fat diets did not show positive effects. The study shows that the syndrome also becomes better with a weight loss. Conclusion: More research is needed on the various dietary approaches effects on women with polycystic ovary syndrome in larger study populations to identify the effects of different dietary approaches.
84

The roles of the plasminogen activator and matrix metalloproteinase systems in ovulation and corpus luteum formation

Bodén, Ida January 2004 (has links)
Proteases of the plasminogen activator (PA) and the matrix metalloproteinase (MMP) enzyme systems are expressed in the ovulatory follicle and in the developing corpus luteum (CL). However, the functional role of these extracellular degrading protease systems in the ovulatory and CL development processes remains elusive. The first aim of this thesis was to develop a mouse model to study gonadotropin-induced CL formation. The second aim was to study the involvement of the PA and the MMP systems in gonadotropin-induced ovulation, and in CL formation and function. A mouse model for gonadotropin-induced CL formation was developed in order to control the timing of CL formation. In this model, immature mice were induced to ovulate by administrating gonadotropins and the endogenous prolactin surges were mimicked by administration of prolactin twice daily from day 2 of CL development. We observed that steroidogenic acute regulatory protein (StAR) mRNA was highly expressed at days 3 and day 6 of CL development and the levels remained high until late stages of CL regression. Since mice lacking plasminogen (plg-/-) only have a 14% reduction of ovulation efficiency, our hypothesis was that the MMP system could compensate for the loss of plasminogen. When administrating the MMP-inhibitor galardin to gonadotropin-primed ovulating mice, we found that wild-type mice (plg+/+ and C67BL/J6) and heterozygous mice (plg+/-) had an 18-20% reduction in ovulation efficiency as compared to untreated mice. Two models for CL formation, the adult pseudopregnant (psp) mouse model and a model whereby immature gonadotropin-primed mice were treated with prolactin, were used to study the formation and function of the CL in plg-/- mice treated with galardin. At day 3 of CL development, we found no alterations other than a slightly lower number of CL in plg-/- mice. This is most likely a secondary effect of the lower ovulation efficiency found in these mice. On the other hand, we found a 54% reduction in serum progesterone levels in plg-/- mice and a 37% reduction in the plg+/- mice as compared to wild type mice. At day 6 of CL development we saw a 45 % reduction of serum progesterone level in the plg-/- mice and a 22 % reduction in the plg+/- mice. A similar trend was observed at day 3 of CL development in immature gonadotropinprimed mice treated with prolactin. Galardin treatment did not alter the results significantly and the CLs were healthy and viable in these mice. In conclusion, our data suggest that both plasminogen and MMPs, alone or in combination, are dispensable for ovulation and for the formation of a viable CL under the conditions used in this study. The reduced serum progesterone levels observed in the plg-/- mice did not appear to be a result of defective CL formation. Instead, plasmin may have a novel role in the maintenance of luteal function. StAR expression may also be a good marker for CL development and regression in mice.
85

Phosphatidylethanolamine deficiency in mammalian cells

Bai, Helin Daniel Unknown Date
No description available.
86

Developmental and Reproductive Toxicity of Progestagens in the Xenopus (Silurana) tropicalis Test System

Säfholm, Moa January 2014 (has links)
Progestagenic compounds are emerging contaminants found in surface and ground water around the world. Information on the effects and potency of progestagens is needed in order to understand the environmental risks posed by these compounds. Using the Xenopus (Silurana) tropicalis test system, developmental and reproductive toxicity after exposure to selected progestagens were determined. Larval exposure to levonorgestrel (LNG) severely impaired oviduct and ovary development causing sterility. No effects on testicular development, spermcount or male fertility were observed. Hepatic mRNA expression of the androgen receptor was increased in the females indicating that the receptor is involved in LNG-induced developmental reproductive toxicity. Exposure of adult females to LNG, norethindrone (NET) or progesterone (P) increased the proportions of previtellogenic oocytes and reduced the proportions of vitellogenic oocytes compared with the controls, indicating an inhibited vitellogenesis. The effects on oocyte development were ascertained at environmentally relevant concentrations of LNG, NET and P (1.3, 1 and 10 ng/L respectively). Since unintentional co-exposure of progestagens and ethinylestradiol (EE2) occurs in wildlife and also in human infants, data on mixture effects of combined exposures to these hormones during development are needed. Co-exposure during development showed antagonistic effects of EE2 and LNG. EE2 caused a female biased sex ratio which showed a tendency to be antagonized by LNG. Moreover, the hepatic AR induction by LNG was counteracted by co-exposure to EE2. In conclusion, the results show that female amphibians are susceptible to reproductive toxicity of progestagens after developmental exposure as well as after adult exposure during the breeding period. The differentiating Müllerianduct and ovary, and the egg development are sensitive targets for progestagens. Finally, the findings reported in this thesis show that environmental progestagens impairs reproductive function in amphibians and may present a threat to reproduction in wild populations.
87

Paršavedžių 4 metų amžiaus kiaušidžių folikulų įvairių stadijų palyginimas ir charakteristika / Sows 4 years age ovarian various stages follicles comparison and characteristic

Foktaitė, Erika 05 March 2014 (has links)
Buvo nustatinėjami paršavedžių folikulų įvairių stadijų dydžiai. / Determined in sows of different stages of follicle sizes.
88

Phosphatidylethanolamine deficiency in mammalian cells

Bai, Helin Daniel 11 1900 (has links)
Almost all mammalian cells contain energy-producing organelles called mitochondria. Phosphatidylethanolamine (PE) is a phospholipid which has been implicated to be important for mitochondrial function. The majority of mitochondrial PE is synthesized in mitochondria using the phosphatidylserine decarboxylase (PSD) pathway. To test the hypothesis that PE made from the PSD pathway is required for mitochondrial function, three Chinese Hamster Ovary Cell lines with different PSD-pathway defects were studied. These three cell lines referred to as PSB-2, R-41, and PSD knockdown cells all had ~35% reductions in mitochondrial PE levels compared to the parental cell line. As a result, the mitochondria from all three cell lines have abnormally high sedimentation densities and increased membrane potentials. However, the energy production, motility, and morphologies of each type of mutant mitochondria were each distinctly different from their parental cell line. / Experimental Medicine
89

GABA-steroid effects in healthy subjects and women with polycystic ovary syndrome / GABA-steroid effects : in healthy subjects and women with polycystic ovary syndrome

Hedström, Helena January 2011 (has links)
Background: The progesterone metabolite allopregnanolone is involved in several clinical conditions in women, e.g. premenstrual dysphoric disorder. It is a very potent GABA-steroid with GABA-A receptor effects similar to other GABA-agonists, e.g. benzodiazepines, and it causes sedation. An objective way to examine effects on the GABA-A receptor in humans is to measure saccadic eye velocity (SEV), which is reduced by GABA-agonists, e.g. allopregnanolone. Animal studies suggest that allopregnanolone is involved in the regulation of gonadotropin secretion via the GABA-A receptor, but this has not been studied in humans. Polycystic ovary syndrome (PCOS) is the most common endocrine disturbance among women of fertile age (5–10%), characterized by polycystic ovaries, menstrual dysfunction, hyperandrogenity, and 50% have obesity. Studies have shown higher allopregnanolone levels in overweight people. PCOS women have increased levels of androstanediol, an androgen metabolite which is an GABA-A receptor agonist. Tolerance often occurs when persons are exposed to high levels of GABAergic modulators. It has not been studied whether GABA-A receptor sensitivity in PCOS women is changed. Another progesterone metabolite, isoallopregnanolone, is the stereoisomere of allopregnanolone but has not been shown to have any GABA-A receptor effect of its own. Instead it has often been used to control steroid specificity to allopregnanolone. Aims: To compare the effects of allopregnanolone and isoallopregnanolone on gonadotropin secretion. To compare allopregnanolone levels, GABA-A receptor sensitivity to allopregnanolone and effects on gonadotropin secretion in both cycle phases and PCOS conditions. To examine pharmacokinetics and pharmacodynamic properties for isoallopregnanolone. Method: In the follicular phase healthy women were examined for the effect of allopregnanolone or isoallopregnanolone on gonadotropin secretion. PCOS women and healthy women in both cycle phases were given allopregnanolone and the differences in effects on SEV were examined, as well as changes in serum levels of gonadotropins and allopregnanolone at baseline and during the test day. Pharmacokinetics and GABA-A receptor sensitivity using SEV were explored for isoallopregnanolone in healthy women. Results: Allopregnanolone decreases gonadotropin serum levels in healthy controls in both cycle phases, but has no effect on gonadotropin secretion in women with PCOS. PCOS women have higher baseline serum levels of allopregnanolone than follicular phase controls, but lower levels than luteal phase controls. PCOS women show greater reduction in SEV to allopregnanolone than controls. Isoallopregnanolone has no effect on gonadotropin secretion. There is an effect of isoallopregnanolone on SEV, explained by a metabolism of isoallopregnanolone into allopregnanolone. Conclusion: There are significant differences in the GABA-A receptor response to a GABA-steroid in different endocrine conditions in women of fertile age examined with saccadic eye velocity. The GABA-steroid allopregnanolone decreases gonadotropin serum levels in healthy women but not in PCOS women. The lack of effect on gonadotropins by isoallopregnanolone suggests an involvement of the GABA-A receptor.
90

Ovarian hormones and effects in the brain : studies of neurosteroid sensitivity, serotonin transporter and serotonin2A receptor binding in reproductive and postmenopausal women

Wihlbäck, Anna-Carin, January 2004 (has links)
Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Page generated in 0.0343 seconds