• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 375
  • 192
  • 72
  • 49
  • 19
  • 18
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 9
  • 5
  • 4
  • Tagged with
  • 976
  • 161
  • 153
  • 111
  • 109
  • 100
  • 98
  • 96
  • 94
  • 89
  • 87
  • 86
  • 70
  • 69
  • 67
  • 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

Regulation of Extra-Pituitary Prolactin in Monocytes and Macrophages

Barrett, Richard 01 January 2018 (has links)
Recently it has been shown that leukocytes are capable of producing prolactin (PRL). Evidence of extra-pituitary PRL (ePRL) production is so far been limited to primates and is not shared across other mammal species such as mice and rats. While ePRL is characterized as an identical protein to traditional pituitary PRL, it is controlled under an alternative promoter and is thus regulated differently from pituitary PRL. Little is known about what regulates ePRL or its direct role in human physiology, but given that PRL has well over 300 described functions, it is likely that the autocrine and paracrine effects of this hormone could have far reaching implications in overall physiology. This work takes some of the first steps in understanding how leukocyte ePRL is regulated. Our results show that, adrenergic hormones are one key stimulus in ePRL expression in monocytes/macrophages. This is particularly intriguing considering the opposing role of these two signals in settings such as adipose tissue where adipose tissue macrophages are constantly exposed to pro-lipolytic adrenergic hormones that would in turn stimulate production of an anti-lipolytic hormone, PRL. Further, our work shows that the inflammatory phenotype of the leukocytes influences basal expression of PRL and overall ePRL expression increases significantly as monocytes differentiate into macrophages, as is a common occurrence in adipose tissue. The final portion of our work shows how monocytes/macrophages also respond to preadipocytes directly. These stem cell precursors to mature adipose cells release an unknown factor that stimulates ePRL production in monocytes/macrophages. Analysis of our gene array shows many of the genes stimulated by adipose stem cells alongside PRL are important genes in tissue regeneration and remodeling, a possible role that fits well with known effects of PRL. Understanding such primate specific interactions between the immune system and major metabolic tissues such as adipose fills vital gaps in knowledge that may explain why so many treatments fail when transitioning from mouse models to humans.
2

Effects and interactions of endocrine disrupting chemicals and diet on the mouse reproductive system

Jones, Maren Bell, January 2007 (has links)
Thesis (M.A.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 29, 2007) Vita. Includes bibliographical references.
3

Seasonal changes in some endocrine organs of the vole (Microtus agrestis)

Forsyth, Isabel A. January 1962 (has links)
Considerable progress has been made in determining the factors in the environment which are responsible for the control of seasonal breeding in mammals and birds. There is less information available about how these factors produce their physiological effects. Light has been shown to be very important in the control of vole breeding seasons. Temperature may also have some effect. How these factors act is not known. As part of an attempt to understand how the breeding season of the vole is controlled, an investigation of some of its endocrine organs has been undertaken. Animals have been collected from the field in mid-summer (at the height of the breeding season) and in mid-winter (during the non-breeding period). A total of 174 adult field animals has been studied. As an approximate indication of the reproductive and endocrinological state of the animals, measurements have been made of the weights of their bodies, adrenals, thyroids, gonads and also certain accessory organs (the uteri of females in winter and the seminal vesicles and ventral prostates of males in both summer and winter). From the examination of this data it is clear that there are considerable endocrine changes with season. Furthermore, within both winter and summer populations reproductive sub-groups which show endocrine differences can be recognized. More detailed study of these endocrine differences has involved the use of cytological and histological methods. Because of the trophic control which the adenohypophysis exercises over the other endocrine organs, it may be presumed to be important in bringing about seasonal changes. It has, therefore, received particular study. The adenohypophyses of field animals have been examined by the methods of cytology, histochemistry and bioassay. In order to identify the cells responsible for the production of gonadotrophin and thyrotrophin, the pituitary function of laboratory bred animals has been altered by castration and the administration of goitrogens. In the adenohypophysis of the vole five cell types have been recognized. Oval basophils which are periodic acid-Schiff (PAS) positive and aldehyde fuchsin (AF) negative. They react to castration by degranulation and the subsequent formation of colloid filled castration cells. They are considered to secrete gonadotrophins. In field animals it has been found that the gonadotrophin producing cells (gonadotrophs) of winter animals are markedly different from those of summer animals. The gonadotrophin content of the pituitaries of male voles in winter and in summer has been studied by means of bioassay. In the summer the vole pituitary contains well granulated gonadotrophs and gonadotrophic hormone can be detected. In winter the gonadotrophs are vesiculated and no gonadotrophic hormone can be detected. This indicates that the granulated gonadotrophs contain hormone, but that the vesiculated cells are depleted of active gonadotrophic principles. Angular basophils which are PAS positive and AF positive. They react to the administration of goitrogen by the formation of colloid filled thyroidectomy cells. They are considered to secrete thyrotrophin. They show no marked changes with season, as would be anticipated from the lack of marked change in the thyroid itself. Round acidophils which show no marked change with season. This study provides no indication as to their function. A second type of acidophil which is numerous and well developed only in females which are pregnant or show signs of mammary development. It is suggested that they may be the source of prolactin. The adenohypophysis also contains a few large cells with poor staining qualities. They do not show any marked changes with season or in response to either castration or the administration of goitrogens. Their function is not known. The gonads were, in general, found to exhibit the expected seasonal change in activity. Sexually inactive males in winter may be divided into two groups on the basis of the structure of the tunica albuginea. It is suggested that these two groups represent, respectively, regressed males, which were sexually active in the preceding summer, and inhibited males, which were born late in the season and have never been sexually active. Similarly, on the basis of uterine weight, female voles in winter can be divided into two groups, parous and non-parous. The pituitary cytology of regressed and inhibited males, parous and non-parous females in winter is similar. In one winter collection the males show considerable evidence of being sexually active. This suggests the operation of a factor or factors other than light and temperature in the control of vole breeding seasons. These males were distinguished from the males in other winters by differences in pituitary cytology. The study of the pituitary suggests that gonadal changes at the end of the breeding season are secondary to changes in the pituitary. The alternative possibility, that the gonads are not competent to respond to pituitary hormones, was tested experimentally. Commercial gonadotrophins were injected into winter field animals and into laboratory bred animals whose sexual development had been inhibited by maintaining them on short days in the cold. The results suggest that the gonads of such animals are able to respond to gonadotrophins. The adrenal has been found to undergo marked changes in weight with season. In summer there is also a sex difference in adrenal weight. These weight changes can be correlated with striking histological differences in the inner regions of the adrenal cortex. In winter voles the adrenal cortex possesses a juxtamedullary zone. It is similar in cytological appearance to the X zone of mice and the two zones are seemingly homologous. The zone is present in all winter field voles, whether regressed or inhibited males, parous or non-parous females. The zone is small or absent in the adrenals of sexually active males. It must, therefore, be formed secondarily in the adrenals of regressed males. It also reappears in a similar, though not identical, form in males after castration. The zone can also disappear from females, but is present in an especially well developed form in all pregnant and lactating animals. Multipara and primipara differ in the details of the structure of the juxtamedullary zone. These changes are clearly related to sexual activity, but their significance is not known. The epithelium lining the ventral prostate is the site of marked stimulation in winter field males and in castrated laboratory animals. It is possible that the adrenal is the source of the hormone responsible for this stimulation. The zona glomerulosa and zona fasciculata of the adrenal cortex also show cytological and histological change with season. Their structure in the winter males which may have been sexually active suggests that these changes are not primarily related to sexual activity. The principal conclusions which can be drawn from this study are: That in the vole there is functional differentiation of adenohypophyseal cells. Two cell, types have been recognized which are clearly related to the production and secretion of gonadotrophic and thyrotrophic hormones, respectively. A third cell type is probably the source of prolactin. There is no evidence available on the function of the other two cell types which have been recognized. That the cessation of breeding in winter in the vole is apparently brought about by a cessation of both the synthesis and the secretion of gonadotrophin. That there are striking changes in the juxtamedullary region of the vole adrenal which appear to be related to sexual activity.
4

Seasonal effects of treated sewage effluents upon the reproduction and development of European freshwater molluscs

Clarke, Neil January 2009 (has links)
The most widespread evidence of environmental endocrine disruption in aquatic wildlife is from the feminising effects of oestrogenic endocrine disrupting compounds. However, very little is known of the effects of these chemicals (and others) upon freshwater molluscs found in our river and lakes. This thesis aimed at evaluating the effects of treated sewage effluent upon the reproductive and developmental cycle of a range of commonly found European freshwater gastropod molluscs. Initial mesocosm experiments were undertaken to test a range of mollusc species for their the suitability to the experimental system, and to test adult snails for their reproductive and developmental responses during spring to summer time. With suitable species chosen, P.corneus, a pulmonate species (sequential hermaphrodite), and V. Viviparus a prosobranch species (dioeious; separate sexes), full reproductive output was assessed over summertime and into autumn, along with developmental responses amongst the F1 generation of snails. My results suggest that the affects of effluent upon the reproductive and developmental cycle of P. corneus are strongly mitigated by both day length and water temperature (day length is most important with V. viviparus); results are sensitive to seasonal effects. However, at the peak of reproduction mid summer, P. corneus produced significantly more egg masses in effluent (100% effluent particularly), and more than one parameter of reproduction was affected. Egg masses were significantly smaller in effluent and contained significantly fewer eggs per mass. Further, there were indications that total reproductive output was increased (100% effluent significantly) in effluent compared to the river water control. In the prosobranch species V. viviparus results were less convincing, however, in 100% effluent a second reproductive peak occurred that was not seen in river water. Further, in both species there was a failure of certain reproductive parameters to observe the normal seasonal decline towards winter. In P. corneus there was a failure to stop producing egg masses in effluent, in V. viviparus the second reproductive peak in effluent could also threaten their survival with winter approaching. Developmental effects in the F1 generation were the subject of preliminary investigations, however, F1 V. viviparus demonstrated a higher than normal incidence of intersex (male and female developmental features) in effluent, and P. corneus appeared to have disturbed reproductive function (disturbance of both male and female reproductive function in the ovotestis). Therefore, both of these species of molluscs demonstrated that they are sensitive to the effects of effluent in mesocosm studies. However, we need to understand much more about their responses to effluent; in particular whether these effects could have repercussions for wild mollusc populations, and whether these effects could occur over more than one generation of snail threatening the survival of wild populations of molluscs.
5

Development and validation of novel molecular techniques to elucidate mechanisms of endocrine disruption

Park, June-Woo. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Zoology-Environmental Toxicology, 2008. / Title from PDF t.p. (viewed on Mar. 30, 2009) Includes bibliographical references. Also issued in print.
6

Kognitive Leistungen bei Patienten mit angeborenen und erworbenen Hormonstörungen

Batisweiler, Georgia. January 1995 (has links)
Thesis (doctoral)--Universität der Bundeswehr München, 1995. / Includes bibliographical references.
7

Kognitive Leistungen bei Patienten mit angeborenen und erworbenen Hormonstörungen

Batisweiler, Georgia. January 1995 (has links)
Thesis (doctoral)--Universität der Bundeswehr München, 1995. / Includes bibliographical references.
8

An investigation of type 2 diabetes self-management in Taiwan

Wu, Hsiu-Li January 2009 (has links)
In Taiwan, as in other countries, type 2 diabetes is a major public health problem. Taiwanese nurses are being called upon to play an increasingly large role in diabetes care, but little is known about the factors that contribute to good or poor diabetes self-management in the Taiwanese context. This study is an exploratory investigation of Taiwanese women’s experiences of living with type 2 diabetes. Adopting an open-ended qualitative approach, the research aimed to discern personal characteristics, strategies, socio-cultural and health system factors that affected women’s ability to manage their condition effectively. Thirty-eight women were interviewed. These included twenty women who were nominated by health professionals as being effective at diabetes self-management and eithteen who were considered to have difficulties, in controlling their HbA1c. Five senior diabetes nurses were also interviewed. Data was analysed thematically. The study found that for many women, their diabetes diagnosis was marked by profound shock and change in their sense of self. Learning to live with diabetes was an ongoing ‘journey’ in which women engaged in a range of strategies to acquire information and support, to gain a sense of control over their condition and to find a health care provider they could trust. The findings challenge the prevailing medical model that defines ‘successful’ self-management on the basis of clinical outcomes alone. Rather, self-management was found to be highly contingent upon individual life circumstances. From women’s own perspectives, successful self-management involved coping with a context of severe social stigma and juggling their own self-care alongside maintenance of multiple social gender roles and financial responsibilities, often in the face of social or economic difficulties. The research points to a need for health professionals to adopt a non-judgemental, individualised and empowering philosophy in their approach to diabetes care whereby education and treatment is tailored to the specific and complex needs of individual patients.
9

Studies on the hormonal activity of wastewater during its treatment

Kirk, Lucy Ann January 2002 (has links)
No description available.
10

The endocrine control of reproductive processes in the nephtyidae (Annelida : polychaeta)

Bentley, M. G. January 1984 (has links)
No description available.

Page generated in 0.0615 seconds